Meeting Abstracts

Earth-Sun System Exploration 5 Conference
Kona, HI, USA, January 13 - 19, 2013



Transient solar wind structure intermediate to turbulent flow and fast CMEs

B.V. Jackson, , H.-S. Yu, A. Buffington, P.P. Hick and J.C. Mejia-Ambriz (UCSD/CASS)

Borovsky (JGR, 117, 2012) and others have postulated that the larger structure differences in the solar wind depart from what is expected of turbulent flow as shown by magnetic field and velocity measurements near Earth. Clearly one example are fast CMEs that retain some semblance of a difference from deep in the corona. However, there is another type of solar wind flow more ubiquitous over the solar surface that we explore here. We present some of the observations related to this solar wind structure difference that we have observed. These observations and their analyses include; the manifestation of the jetting response in the corona and heliosphere, the non-static flow observed in the corona above the solar polar holes, and velocity shears observed in the plasma tails of comets. These remote-sensing observations provide an interesting, comprehensive story that we explore more completely in this presentation.




2012 Fall AGU Meeting
San Francisco, CA, USA, December 3 - 7, 2012



Tracing polar jets into the inner heliosphere by using images from the LASCO C2 and STEREO COR2 coronagraphs and 3D tomographic reconstructions from interplanetary scintillation and the Solar Mass Ejection Imager (SMEI)

H.-S. Yu, B.V. Jackson and A. Buffington (UCSD/CASS)

During recent years coordinated efforts to gather data from a large number of spacecraft (Hinode, SDO, SOHO, STEREO, and SMEI) and ground-based instruments using interplanetary scintillation (IPS), have allowed a study of the polar jetting process, and tracing the jet response into the heliosphere in a statistical manner. The brightest of these polar jets observed by the Hinode XRT and the SDO/AIA show a positive correlation with high-speed responses traced into the interplanetary medium. LASCO C2 and STEREO COR2 coronagraph images allow measurement of the coronal response to some of these jets, and the nearby background solar wind velocity giving a determination of their speeds and energies that we compare with Hinode and AIA observations. By using the full data set from white light SMEI images, and IPS velocities, we are able to track these same high speed solar jet responses into the inner heliosphere in order to determine the extent to which they retain their identity at large solar distances.




3-D reconstruction of the inner heliosphere from remote-sensing data: a global solar wind boundary that includes CME transient effects

B.V. Jackson, H.-S, Yu, P. Hick and A. Buffington (UCSD/CASS)

At UCSD, remote-sensing analyses of the inner heliosphere have been regularly carried out using interplanetary scintillation (IPS) data for almost two decades. These analyses have measured and reconstructed 3-D solar wind structure throughout this time period. These global results, especially using Solar-Terrestrial Environment Laboratory (STELab) IPS observations, provide a time-dependent inner boundary in density and velocity that is nearly complete over the whole heliosphere for the major part of each year and with a time cadence of about one day. When using the IPS velocity analyses we can accurately convect-outward solar surface magnetic fields and thus provide values of the field throughout the global volume. In the inner heliosphere results of these 3-D analyses of density, velocity, and vector magnetic field have been compared successfully with in-situ measurements obtained near Earth, STEREO, Mars, Venus, MESSENGER, and at the Ulysses spacecraft. The resulting precise time-dependent inner boundary of these parameters can be further extrapolated outward to the edge of the heliosphere using current 3-D MHD modelling techniques. Here we present sample determinations of this boundary for recent IPS data, and give the details that allow the interpolation of these boundary values during IPS “outage” periods when insufficient remote-sensing data are available to provide complete daily coverage.




The ability of radio heliospheric remote sensing observations to provide global solar wind parameters

B.V. Jackson, P. Hick, A. Buffington and H.-S. Yu (UCSD/CASS)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
R. Fallows (ASTRON, the Netherlands Inst. for Radio Astronomy, Dwingeloo, Netherlands)

Heliospheric remote sensing, in particular those using Interplanetary Scintillation (IPS) observations, allow the 3-D reconstruction of solar wind parameters globally. These parameters include velocity, density, and by extrapolation from solar surface magnetogram observations, vector magnetic field components. Since the year 2000, the Solar-Terrestrial Environment Laboratory (STELab), Nagoya University, Japan, has provided a source of IPS data with short-enough latency to enable forecasts of these solar wind parameters throughout the inner heliosphere. Over time these techniques have been improved upon with data from other radio sites (Ootacamund - Ooty - India; and the European Incoherent SCATter - EISCAT - radio telescopes based across Northern Scandinavia). Here we review the improvements, limitations, and the potential future of these techniques. In particular in one new development, the ability to measure polarization from radio sources allows the possibility to use Faraday rotation inputs to reconstruct heliospheric vector magnetic fields without a reliance on solar surface magnetic field extrapolation.




Remote Sensing of Solar Wind Velocity Applying IPS Technique using MEXART

J.C. Mejia-Ambriz (UCSD/CASS, San Diego, USA and Instituto de Geofisica, UNAM, Morelia, Mexico)
A. Gonzalez-Esparza and E.R. Hernandez (Instituto de Geofisica, UNAM, Morelia, Mexico)

Radio waves coming from compact cosmic radio sources are scattered by electron density fluctuations in the solar wind plasma, producing a diffraction pattern at Earth which moves along with the solar wind. This phenomenon results into flux density fluctuations observed by a radio telescope and it is known as Interplanetary Scintillation (IPS). By employing IPS observations, it is possible to track solar wind velocities in the inner heliosphere. The Mexican Array Radio Telescope (MEXART) is an new instrument devoted to IPS observations at 140 MHz. We present preliminary estimates of solar wind velocities by using IPS observations of the MEXART.




AOGS-AGU (WPGM) Joint Assembly
Singapore, Malaysia, August 13 - 17, 2012



Heliospheric observations using LOFAR and EISCAT

M. Bisi (Aberystwyth Univ., Aberystwyth, United Kingdom)
R. Fallows (ASTRON, The Netherlands Inst. for Radio Astronomy, Netherlands)
E. Jensen (ACS-Consulting/MMT Obs., US)
S. Hardwick (Aberystwyth Univ., Aberystwyth, United Kingdom)
B. Jackson (Univ. of California, San Diego, US)
A. Asgekar (ASTRON, The Netherlands Inst. for Radio Astronomy, Netherlands)
J. Clover (Univ. of California, San Diego, US)

Remote-sensing studies of the inner heliosphere using radio telescopes and arrays are carried out through observations of interplanetary scintillation (IPS). These observations record radio waves from compact astronomical natural sources. Such sources can also be used for the observation of heliospheric Faraday rotation (FR) as well as using spacecraft radio beacons. FR is the rotation that occurs as an electromagnetic wave traverses a birefringent medium such as the solar corona and solar wind; it is the integrated product of the electron density and the component of the solar magnetic field parallel to the wave vector of the electromagnetic wave.FR, combined with IPS or white-light imager observations, can provide essential information on the Sun’s extended magnetic-field structure. We specialise in relatively-high-frequency observations of IPS (500 MHz to 6 GHz) using the European Incoherent SCATter (EISCAT) radar, the EISCAT Svalbard Radar (ESR), as well as the Multi-Element Radio-Linked Interferometer Network (MERLIN) radio telescopes. In addition, we are presently working on new low-frequency IPS and FR experiments for the Low Frequency ARray (LOFAR) as well as future observations of IPS using the upcoming EISCAT_3D system and following the planned EISCAT VHF refit this summer to 224 MHz. The data sets from various IPS-capable systems can be used for input to tomographic reconstruction of the inner heliosphere in three dimensions. These employ analyses from the University of California, San Diego (UCSD) three-dimensional (3-D) computer-assisted tomography (C.A.T.) algorithms in addition to other remote-sensing data. The 3-D reconstruction and visualisation tools make it possible to compare multi-point in-situ measurements from various deep-space spacecraft, and allow us to learn further about the solar wind and its subsequent outflow from the Sun, and indeed insights into space-weather forecasting. We will present and discuss the recent-past, present, and future observations and results using these radio systems.




IPS techniques and observations

B. Jackson, J. Clover, H.-S. Yu, P. Hick, A. Buffington (UCSD/CASS)
M. Bisi (Aberystwyth Univ., Aberystwyth, UK)
M. Tokumaru (Nagoya Univ., Nagoya, Japan)

The University of California, San Diego (UCSD) three-dimensional (3D) time-dependent tomography program has been used for well over a decade to reconstruct and forecast coronal mass ejections (CMEs) from observations of interplanetary scintillation (IPS) taken using the Solar-Terrestrial Environment Laboratory (STELab) IPS arrays. Unlike near-solar solar surface propagation models, these analyses fit a solar wind model to inner-heliospheric data, and enable 3D reconstruction of solar wind structure as it transits between Sun and Earth. Here we show the latest analyses using this technique to measure solar wind velocity and density. Using the global velocity data available from IPS we are also able to project outward solar-surface magnetic fields in order to provide reasonable global in-situ magnetic-field component trends from one day to the next. These same extrapolations allow an immediate relationship between any remote heliospheric position to a location on an inner boundary near the solar surface in order to estimate solar particle propagation paths.




SHINE 2012
Wailea Maui, HI, June 25-29, 2012



The 3D global forecast of inner heliosphere solar wind parameters from remotely sensed IPS data

B.V. Jackson, J.M. Clover, P.P. Hick, H.-S. Yu and A. Buffington (UCSD/CASS)
M. Tokumaru (Nagoya Univ.)

At UCSD, remote-sensing forecast analyses of the inner heliosphere have been regularly carried out using interplanetary scintillation (IPS) data. These analyses have measured and reconstructed the 3-D time-dependent solar wind structure for almost two decades using Solar-Terrestrial Environment Laboratory (STELab) IPS observations. More recently we have provided an even more accurate 3-D forecast analyses by incorporating in-situ spacecraft measurements into the remotely-sensed volumes. When using the IPS velocity analyses we can accurately convect-outward solar surface magnetic fields using potential field model techniques, and thus also provide values of the field throughout the global volume. This forecast analysis is being operated in real time at the UCSD website http://ips.ucsd.edu, and at the NASA Goddard Community Coordinated Modeling Center (CCMC) website: http://iswa.ccmc.gsfc.nasa.gov:8080/IswaSystemWebApp/index.jsp? The results of these time-dependent 3-D analyses of density, velocity, and vector magnetic field are compared with in-situ measurements obtained in real time near Earth, and are also displayed in real time at all the other inner planets: Mercury, Venus and Mars as well as at the locations of the STEREO A and B spacecraft. We display these forecasts obtained from our UCSD website at this poster presentation, and discuss a metric that we have devised to determine how well these forecasts agree with ongoing in-situ measurements.

PPT Poster


The 3D reconstructed global solar wind boundary from remote-sensing IPS data

H.-S. Yu, B.V. Jackson, P.P. Hick, A. Buffington and J.M. Clover (UCSD/CASS)
M. Tokumaru (Nagoya Univ.)

At UCSD, remote-sensing analyses of the inner heliosphere have been regularly carried out using interplanetary scintillation (IPS) data for almost two decades. These analyses have measured and reconstructed 3D solar wind structure throughout this time period. These global results, especially using Solar-Terrestrial Environment Laboratory (STELab) IPS observations, provide a time-dependent inner boundary in density and velocity that is nearly complete over the whole heliosphere for the major part of each year and with a time cadence of about one day. When using the volumetric velocity provided by UCSD time-dependent tomography, we can accurately convect-outward solar surface magnetic fields and thus provide values of the magnetic field throughout the global volume. These resulting time-dependent 3D reconstructed results of density, velocity, and vector magnetic field, which are available from 15 solar radii out to 3.0 AU, have been compared successfully with in-situ measurements obtained near Earth, STEREO, Mars, Venus, MESSENGER, and at the Ulysses spacecraft. Here we present sample determinations of these global solar wind boundary for 3D-MHD models from recent IPS data.

PPT Poster


Validation of Inner Heliospheric Models near Solar Minimum: WSA-Enlil, MAS-Enlil, SWMF, and IPS Tomography Models

L.K. Jian (Univ. of Maryland, College Park, MD, USA), and Heliophysics Science Division, NASA GSFC, MD, US
P.J. MacNeice (Heliophysics Science Division, NASA GSFC, MD, USA)
B.V. Jackson (UCSD/CASS, La Jolla, CA, USA)
R. Evans (Heliophysics Science Division, NASA GSFC, MD, US, and Oak Ridge Associated Univ., TN, USA)
D. Odstrcil (Heliophysics Science Division, NASA GSFC, MD, USA, and George Mason Univ., VA, USA)
P. Riley (Predictive Science Inc, CA, USA)
I.V. Sokolov (Univ. of Michigan, MI, USA)

Since the last SHINE workshop, the new versions of MAS (MHD-Around-A-Sphere) – Enlil, SWMF (Space Weather Modeling Framework), and IPS (Interplanetary Scintillation) Tompography models have become available to request runs at the Community Coordinated Modeling Center (CCMC). We have selected Carrington rotations (CRs) 2056 – 2062 (April 27 – November 4 in 2007) to represent the solar minimum phase, because Ulysses perihelion pass in this period can enable us to validate the heliospheric models out of the ecliptic plane. We have obtained the results from the WSA (Wang-Sheely-Arge)-Enlil model using the synoptic photospheric magnetograms from NSO (National Solar Observatory) at Kitt Peak, GONG (Global Oscillation Network Group), and MWO (Mount Wilson Observatory), SWMF using GONG magnetographs, MAS-Enlil model using MDI (Michelson Doppler Imager on board SOHO) magnetograms, and IPS Tomography models. By comparing the modeling results of various solar wind structures and parameters with the observations at multiple locations from 0.3 to 2 AU, including OMNI data, Ulysses, Venus Express (VEX), and MESSENGER, we access the performance of these models in capturing the solar wind features and predicting the solar wind parameters. The strengths and shortcomings of these models will be drawn, and the effect of photospheric magnetograms from different observatories will be studied too.




Solar Wind 13
Kona-Kailua, HI, June 18 - 22, 2012



Using comet plasma tails to study the solar wind

B.V. Jackson, A. Buffington, J.M. Clover, P.P. Hick, H.-S. Yu (UCSD/CASS)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)

The plasma tails of comets have been used as probes of the solar wind for many years, and well before solar wind measurements enabled direct measurements. The much greater regularity of images from space instruments now reveals far more detail and extent of outward solar wind flow than previously possible. These analyses mark the location of the solar wind flow in three-dimensions over time much as do in-situ measurements. Data from comet plasma tails using coronagraphs and heliospheric white-light imagers view closer to the Sun than spacecraft have ventured to date. These show that this flow is chaotic and highly variable, and not the benign, regular outward motion of a quiescent plasma. While this is no surprise to those who study and characterize the solar wind in-situ or use remotely-sensed interplanetary scintillation techniques, spacecraft images allow a visualization of this as never-before possible. Here we summarize the results of a technique used to determine solar wind velocity on multiple comets observed by the Solar Mass Ejection Imager (SMEI) and also using images from the Heliospheric Imager on board the STEREO A spacecraft. Finally we present results using an analysis technique that measures this same behavior on coronagraph images in the low corona.




The 3D Analysis of Polar Jets Using Images from LASCO C2 and STEREO COR2 Coronagraphs and the Solar Mass Ejection Imager (SMEI)

H.S. Yu, B.V. Jackson, J. Clover, and A. Buffington (UCSD/CASS

The high cadence X-ray images taken by the X-ray Telescope onboard Hinode and the Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA) instrument provide an opportunity to observe solar jetting activity. The brightest of these polar jets show a positive correlation with high-speed responses traced into the interplanetary medium. LASCO C2 and STEREO COR2 coronagraph images allow measurements of the coronal response to some of these jets, and the nearby background solar wind velocity giving a determination of their speeds and energies that we compare with Hinode and AIA observations. By using the full SMEI (Solar Mass Ejection Imager) image data set, we are able to track these same high speed solar jet responses into the inner heliosphere in order to determine the extent to which they retain their identity at large solar distances.




Space Weather Workshop
Boulder, CO, April 24 - 27, 2012



The 3-D forecast of inner heliosphere solar wind parameters from remote-sensing and in-situ data

B.V. Jackson and H.-S. Yu (UCSD/CASS, La Jolla, CA, USA)
P.P. Hick (UCSD/CASS and UCSD/SDSC, La Jolla, CA, USA)
A. Buffington and J.M. Clover (UCSD/CASS)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)
L. Jian (Univ. of Maryland, College Park, MD, USA and
NASA Goddard Space Flight Center, Greenbelt, MD, USA)

At the University of California, San Diego (UCSD), remote-sensing forecast analyses of the inner heliosphere have been regularly carried out using interplanetary scintillation (IPS) data. These analyses have measured and reconstructed the 3-D time-dependent solar wind structure for almost two decades using Solar-Terrestrial Environment Laboratory (STELab) IPS observations. More recently we have provided an even more accurate 3-D forecast analysis by incorporating in-situ spacecraft measurements into these remotely-sensed volumes. When using the IPS velocity analyses we can accurately convect-outward solar surface magnetic fields using potential field model techniques, and thus also provide values of the field throughout the global volume. These extrapolations allow an immediate relationship of any remote heliospheric position to the corresponding location on an inner boundary near the solar surface and an instantaneous trace-back to this boundary in order to estimate potential solar particle propagation paths. This forecast analysis is being operated in real time at the UCSD website http://ips.ucsd.edu, and at the NASA GSFC Community Coordinated Modeling Center (CCMC) website: http://iswa.ccmc.gsfc.nasa.gov:8080/IswaSystemWebApp/index.jsp? The archival results of these time-dependent 3-D analyses of density, velocity, and vector magnetic field are compared with in-situ measurements obtained near Earth, and at STEREO, Mars, Venus, MESSENGER, and the Ulysses spacecraft.

PPT Poster



Space Weather: The Space Radiation Environment
11th Annual International Astrophysics Conference.
Palm Springs, CA, March 19 - 23, 2012



3-D reconstruction of the inner heliosphere from remote-sensing and in-situ data: tracing magnetic field structure to near the solar surface

B.V. Jackson, Hsiu-Shan Yu, P.P. Hick, A. Buffington, J.M. Clover (UCSD/CASS)
Munetoshi Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)
Lan Jian (Inst. of Geophysics and Planetary Physics, UCLA, CA, USA

At UCSD, remote-sensing analyses of the inner heliosphere have been regularly carried out using interplanetary scintillation (IPS) data. These analyses have measured and reconstructed the 3-D time-dependent solar wind structure for almost two decades using Solar-Terrestrial Environment Laboratory (STELab) IPS observations. More recently we have provided even more accurate 3-D analyses by incorporating in-situ spacecraft measurements into these remotely-sensed volumes. When using these IPS velocity analyses we can accurately convect-outward solar surface magnetic fields measured and thus provide values of the field throughout the global volume. These extrapolations allow an immediate location of any remote heliospheric position to an inner boundary near the solar surface, in order to estimate potential solar particle propagation paths. In the inner heliosphere results of these time-dependent 3-D analyses of density, velocity, and vector magnetic field have been compared successfully with in-situ measurements obtained near Earth, and at STEREO, Mars, Venus, MESSENGER, and the Ulysses spacecraft.




3-D reconstruction of the inner heliosphere from remote-sensing data: a global solar wind boundary that includes CME transient effects

Hsiu-Shan Yu, B.V. Jackson, P.P. Hick, A. Buffington, J.M. Clover (UCSD/CASS)
Munetoshi Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)
Lan Jian (Inst. of Geophysics and Planetary Physics, UCLA, CA, USA

At UCSD, remote-sensing analyses of the inner heliosphere have been regularly carried out using interplanetary scintillation (IPS) data for almost two decades. These analyses have measured and reconstructed 3-D solar wind structure throughout this time period. These global results, especially using Solar-Terrestrial Environment Laboratory (STELab) IPS observations, provide a time-dependent inner boundary in density and velocity that is nearly complete over the whole heliosphere for the major part of each year and with a time cadence of about one day. When using the IPS velocity analyses we can accurately convect-outward solar surface magnetic fields and thus provide values of the field throughout the global volume. These extrapolations allow an immediate location and a track of any remote heliospheric position to the inner boundary surface in order to estimate potential solar particle propagation paths. In the inner heliosphere results of these 3-D analyses of density, velocity, and vector magnetic field have been compared successfully with in-situ measurements obtained near Earth, STEREO, Mars, Venus, MESSENGER, and at the Ulysses spacecraft. The resulting precise time-dependent inner boundary of these parameters can be further extrapolated outward to the edge of the heliosphere using current 3-D MHD modelling techniques. Here we present sample determinations of this boundary for recent IPS data, and provide some of the details that allow the interpolation of these boundary values during STELab “outage” periods where insufficient remote-sensing data are available to provide complete daily coverage.




SDO-4/IRIS/Hinode Workshop,
Dynamics and energetics of the coupled solar atmosphere:
the synergy between state-of-the-art observations and numerical simulations Monterey, CA, March 12 - 16, 2012



A preliminary study of the HOP-187 jet analysis

B.V. Jackson, H.-S. Yu, A. Buffington, J. Clover (UCSD/CASS)
M. Shimojo (Nobeyama Solar Radio Observatory, NAOJ, NINS, Japan)
N. Sako (Dept. of Astronomical Science, Sokendai, NAOJ, Japan)

The Hinode Observing Proposal (HOP)-187, "Tracking X-ray Jets from the Solar Surface to Interplanetary Space" (Jackson and Shimojo, 2011) was carried out successfully during the summer of 2011. On two occasions (00-06 UT 17 June, 2011, and 00-08 UT 22 August 2011) XRT observations were run at a higher cadence over the south polar region in conjunction with LASCO C2 observations that also provided an enhanced 5-minute cadence and 100-sec exposures from this instrument. This campaign effort was joined by the NASA SDO AIA, the Solar TErrestrial RElations Observatory (STEREO) Coronagraph (COR II) and Heliospheric Imagers (HI's), ground-based interplanetary scintillation (IPS) observations from the Solar Terrestrial Environment Laboratory (STELab) and Ootacamund (Ooty), India, and finally data from the Solar Mass Ejection Imager (SMEI). In this data analysis, as in previous campaign-mode operations of the Hinode XRT instrument, we find a positive correlation between the brightest of the polar jets and a high-speed response traced into the interplanetary medium. Here, we report on the preliminary measurements of the jet responses that were observed during this successful HOP-187 campaign.




The 3D Analysis of Polar Jets Using Thomson-Scattering Observations from LASCO C3 Images and the Solar Mass Ejection Imager (SMEI)

H.S. Yu and B.V. Jackson (UCSD/CASS)

The X-Ray Telescope (XRT) onboard Hinode provides an opportunity to observe solar jetting activity above the solar poles. LASCO C3 images allow measurements of the coronal response to some of these jets, giving a determination of their speeds and energies that we compare with Hinode observations (Sako et al. 2010, 38th COSPAR). By using the full SMEI (Solar Mass Ejection Imager) image data set, we are able to study these same solar jet responses in the inner heliosphere. Preliminary results from 3D-reconstructed SMEI pseudo C3 coronagraph images have shown a good agreement at the correct position angles and time with the jet responses observed in LASCO (Jackson, 2012, Adv. in Geosciences). Using the SMEI volumetric data we carry this analysis farther, attempting to determine the extent to which these 3D jet responses maintain their identity into the inner heliosphere.




2011 Fall AGU Meeting
San Francisco, CA, Decemeber 5 - 9, 2011



A study of long-term heliospheric brightness using SMEI data

A, Buffington, J.M. Clover (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
B.V. Jackson (UCSD/CASS)
M.M. Bisi (UCSD/CASS and Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK

The Solar Mass Ejection Imager (SMEI) has been returning white-light photometric maps of nearly the entire sky with a 102-minute cadence for well over eight years. When the usual sidereal and zodiacal backgrounds are removed, the residual maps are used to study CME/ICME events. Moreover, the successful sidereal subtraction provides a certification of SMEI’s photometric accuracy over this time period. Further, since the zodiacal background removal employs a brightness model which does not vary with time, a search for potential long-term changes in the residue can show whether the zodiacal cloud’s dust distribution varies within this portion of the present solar cycle. We present results from studies using SMEI imagery along with a concluded zodiacal-light model.

PPT Poster


Imaging coronal mass ejections and large-scale solar wind structure using Thomson-scattering measurements from SMEI

B.V. Jackson, J.M. Clover, A. Buffington (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK, and UCSD/CASS)
K. Marubashi (Korea Astronomy and Space Science Inst., Daejeon, Republic of Korea)
D.F. Webb (Inst. of Scientific Research, Boston College, Newton, MA, USA)

In January 2010, two coronal mass ejections (CMEs) erupted from near the solar east limb, the first on late 14 January 2010 and the second on 17 January 2010. Both arrived at the Solar TErrestrial RElations Observatory Behind spacecraft (STEREO-B) about six days later. We are able to reconstruct the heliospheric density of both CME events in three dimensions (3D) using data from the Solar Mass Ejection Imager (SMEI) and our tomographic analysis. For each event, we isolate the particular portion of the heliosphere attributed to the transient CME density structure from the tomographic results, and then estimate its extent. The structure of these events is shown in detail in the three-dimensional reconstruction both as pseudo-coronagraph images and later as density at the locations of STEREO-B and the Earth. The first of these CMEs was associated with a magnetic cloud that had a density enhancement near its center. By assuming that this density enhancement extends along the loop, we can use the three-dimensional density analysis to map the extent and orientation of this structure in order to match it to existing magnetic-loop models and to use the remote-sensing observations to constrain the various flux-rope models determined using the in-situ measurements of the 14 January 2010 event.




SMEI and IPS 3-D CME reconstructions, and what they indicate of heliospheric solar wind acceleration

B.V. Jackson, J.M. Clover (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
A. Buffington (UCSD/CASS)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)

The remotely-sensed measurements of coronal mass ejections (CMEs) and their interplanetary counterparts (ICMEs) from Solar Mass Ejection Imager (SMEI) white-light brightness and radio interplanetary scintillation (IPS) data can be used to provide limits on the acceleration and deceleration of transients in the inner heliosphere. As an intermediate measurement between the Sun and 1 AU, the limits provided by remote sensing are convolved with line-of-sight effects and CME/ICME `evolution’ as each feature of the transient moves outward from the Sun. Here we review a few of the popular events and studies that have been presented to show how CME propagation proceeds in the inner heliosphere. Often, the apparent acceleration shown can only be provided by employing an assumption of the CME three-dimensional (3-D) shape, which often changes with solar distance and CME visibility along the line of sight. This assumption can often abrogate the original acceleration measurement. In particular we concentrate here on the analysis of two events during periods in 02-04 November 2003, and also in January 2010 showing how each event provides significantly different acceleration profiles depending on which structures are identified in each transient. Finally, we highlight the strange case of polar coronal jets (that are essentially miniature CMEs) frequently observed to move outward in the polar coronal fast wind at speeds of over three times ambient. These small solar wind transients seem to have disappeared by the time they can be observed in Ulysses in-situ data. Thus, a detailed study of these jets may provide an understanding of smaller-scale CME/ICME deceleration processes.




UCSD Time-dependent tomographic forecasting with interplanetary scintillation and white-light observations

J.M. Clover and B.V. Jackson (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
A. Buffington (UCSD/CASS)
M. Tokumaru, K. Fujiki and M. Hirota (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK and UCSD/CASS)

The University of California, San Diego (UCSD) time-dependent tomography program has been used successfully since the beginning of the year 2000 to remotely sense and forecast interplanetary scintillation (IPS) observations of coronal mass ejections (CMEs). Recently, this program has included real-time ACE data in the analysis. This more-efficiently extends velocity and density measurements obtained near Earth in real time to those derived from remotely-sensed observations, and allows a far more efficient extrapolation from the present time into the future. These analyses are now also used with real-time extrapolations of radial and tangential magnetic fields from the National Solar Observatory. The time-dependent program is also being adapted to provide similar forecasts (but at higher spatial and temporal resolutions) of heliospheric density using Thomson-scattering data from the Solar Mass Ejection Imager (SMEI). Here, we describe the current state of these IPS and SMEI real-time data pipelines and show their usefulness. These demonstrate in near real-time the improved accuracy of the remote-sensing fits with the inclusion of space-borne in-situ density and velocity measurements during the current rising phase of the solar cycle.




Comparative validation of realtime solar wind forecasting using the UCSD Heliospheric Tomography Model

P.J. MacNeice (NASA Goddard SFC, Greenbelt, MD, USA)
A. Taktakishvili (UMBC GPHI, Greenbelt, MD, USA)
B.V. Jackson, J.M. Clover and M.M. Bisi (UCSD/CASS)
D. Odstrcil (George Mason Univ., Physics & Atronomy, Fairfax, VA, USA)

The University of California, San Diego 3D Heliospheric Tomography Model reconstructs the evolution of heliospheric structures, and can make forecast of solar wind density and velocity up to 72 hours in the future. The latest model version, installed and running in near real-time at the Community Coordinated Modeling Center(CCMC), analyzes scintillations of meter wavelength radio point sources recorded by the Solar-Terrestrial Environment Laboratory (STELab) together with real-time measurements of solar wind speed and density recorded by the Advanced Composition Explorer(ACE) Solar Wind Electron Proton Alpha Monitor(SWEPAM). The solution is reconstructed using tomographic techniques and a simple kinematic wind model. Since installation, the CCMC has been recording the model forecasts and comparing them with ACE measurements, and with forecasts made using other heliospheric models hosted by the CCMC. We report the preliminary results of this validation work and comparison with alternative models.




Current and planned solar wind observations using the EISCAT and LOFAR radio-telescope systems

M.M. Bisi (Inst. of Mathematics & Physics, Aberystwyth Univ., Aberystwyth, UK and UCSD/CASS
R.A. Fallows (Inst. of Mathematics & Physics, Aberystwyth Univ., Aberystwyth, UK)
E.A. Jensen (Planetary Science Inst., Tucson, AZ, USA)
A. Breen and M. Xiong (Inst. of Mathematics & Physics, Aberystwyth Univ., Aberystwyth, UK)
B.V. Jackson (UCSD/CASS)

Remote-sensing observations of the inner heliosphere using the technique of interplanetary scintillation (IPS) provide essential information on the velocity and density of developing solar wind structure. For many years, observations of IPS have been undertaken with the European Incoherent SCATter (EISCAT) radio telescopes based across Northern Scandinavia. We are presently developing the IPS experiment for use on new and upcoming cutting-edge instrumentation. Such instrumentation includes the LOw Frequency ARray (LOFAR) which is situated primarily in the Netherlands with additional stations currently sited across central Europe. Using data sets from various IPS-capable systems, the University of California, San Diego (UCSD) three-dimensional (3-D) tomographic-reconstruction and visualisation algorithms can yield reconstruction results for comparison with multi-point in-situ measurements from spacecraft. This makes it possible to study the structure of the inner heliosphere as a whole, including the isolation of individual features or events such as interplanetary coronal mass ejections (ICMEs), stream interaction regions (SIRs), or their interactions with the ambient solar wind as well as the ambient wind itself. We are also testing the Faraday rotation (FR) response at low frequencies using LOFAR. Combined, these techniques have large implications and capabilities for space-weather forecasting. This work is focused on the global structure of the inner heliosphere during the minimum and rise phases of the current solar cycle.




Necessity of 2D image data for determining 3D configurations of magnetic clouds

K. Marubashi (Korea Astronomy and Space Science Inst., Daejeon, Republic of Korea)
M. Tokumaru (Solar-TerrestrialEnvironment Lab., Nagoya Univ., Nagoya, Japan)
B.V. Jackson and J.M. Clover (UCSD/CASS)

The structure of magnetic cloud (MC) has long been studied by fitting in-situ magnetic field measurements to magnetic flux rope models. Such studies generally provide the size and orientation of the model structure, which are taken to be applicable only locally to the portion where the cloud passed the spacecraft. The obtained geometry often changes depending on the models used for the fitting. For example, for a single observational data set, a cylinder model and a torus model often give different cloud axis orientations. Thus we need further consideration about the global configuration to deduce the 3D structure of the MC. 2D images from heliospheric remote sensing measurements provide reliable constraints about the global MC structure. With the above in mind we attempt to study the global structure of MC by combining the model fitting results and the 3D reconstruction data from the Solar Mass Ejection Imager (SMEI) and interplanetary scintillations (IPS). For this purpose, we first select MC events in which the proton densities are high enough (generally > 20 /cc) in the sheath regions behind the driven shocks and/or in the regions occupied by MCs. Then we examine possible 3D configurations which are consistent with the orientation of the MC axis obtained from model fittings. The global MC structure is finally obtained by applying the constraints from 2D image data. Our preliminary examination shows that the above procedure is helpful for determining the most probable 3D global structures of MCs.




AOGS 2011
Taipei, Taiwan, August 8 - 12, 2011



Forecasting Transient Heliospheric Solar Wind Parameters at the Locations of the Inner Planets

B.V. Jackson, P. Hick, A. Buffington, J.M. Clover (UCSD/CASS)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)

Both interplanetary scintillation (IPS), and Thomson-scattering observations from the Air Force/NASA Solar Mass Ejection Imager (SMEI) allow a determination and forecast of solar wind parameters at the locations of the inner planets. Analysis of these observations yields low-resolution temporal measurements of solar wind velocity and bulk density, and often does so before their arrival at the respective planets. Here we explore the different techniques used, the parameters forecast, and how in the future we can provide even more meaningful information from these remotely-sensed heliospheric measurements.




The 3D Reconstruction of Heliospheric Density Using Interplanetary Scintillation and Thomson-Scattering Observations – Current Progress and Future Prospects

B.V. Jackson, J.M. Clover, A. Buffington, P. Hick (UCSD/CASS)
M. Tokumaru and K. Fujiki (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)
M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)

Both interplanetary scintillation (IPS) and Thomson-scattering observations from the Air Force/NASA Solar Mass Ejection Imager (SMEI) allow a determination of density in the inner heliosphere and its forecast from remote-sensing heliospheric observations. Here we explore our attempts to provide density from these techniques, and our current success in this endeavour. Comparisons of these two different techniques are provided. We would like to provide the best possible measurements of this heliospheric parameter, and here we explore this possibility with larger radio array systems such as the Murchison Widefield Array (MWA) that is now under construction in Western Australia.




SHINE 2011
Snowmass, Colorado, July 11-15, 2011



Investigations of the July-August 2010 CME Event(s)

M.M. Bisi (UCSD/CASS and Aberystwyth Univ., UK)
B.V. Jackson and J.M. Clover (UCSD/CASS)
E.A. Jensen (Planetary Science Inst.)
T.M. Mulligan (Aerospace Corp.)
P.K. Manoharan (Tata Inst. of Fundamental Research)
P.P. Hick (UCSD/CASS)

A complex solar eruption (or set of eruptions) occurred at the start of August 2010 releasing a disappearing filament and halo CME on an Earth-wards trajectory launching from AR 1092. The first ICME arrived on 03 August followed by a second stronger ICME on 04; both were travelling at speeds approximately twice that of the ambient solar wind at the time. The ICMEs triggered a G2-class geomagnetic storm. Here, we look at the 3-D reconstruction of the event(s) from Solar Mass Ejection Imager (SMEI) white-light data, and where possible, interplanetary scintillation (IPS) data. We also discuss flux-rope modelling results as measured by ACE, VEX, and STEREO-B instrumentation. We will discuss and attempt to pull together our findings in the context of the inner heliosphere.




UCSD Time-Dependent Tomographic Forecasting with Interplanetary Scintillation and White Light Observations

J.M. Clover and B.V. Jackson (UCSD/CASS)
P.P. Hick (UCSD/SDSC)
A. Buffington and J.C. Lindford (UCSD/CASS)

The University of California, San Diego (UCSD) time-dependent tomography program has been used successfully since the beginning of the year 2000 to remotely sense and forecast interplanetary scintillation (IPS) observations of coronal mass ejections. Recently, this program has incorporated ACE data in the analysis to more efficiently extend, in real time, near-Earth observations of velocity and density, to those derived from remotely-sensed observations. This allows a more efficient extrapolation from the present time into the future. The time-dependent program has now also been adapted to provide forecasts of heliospheric density using Thomson-scattered brightness from the Solar Mass Ejection Imager (SMEI). Here we describe the current state of these IPS and SMEI real-time data pipelines, and show examples of the improved accuracy of the remote-sensing fits with the inclusion of space-borne in-situ density and velocity measurements.




Observations of Polar-Region Jets and Their Manifestations in the Solar Wind

B.V. Jackson, J.M. Clover, P.P. Hick, A. Buffington and J.C. Linford (UCSD/CASS)
M. Shimojo (Nobeyama Solar Radio Obs., NAOJ/NINS, Japan)
N. Sako (Tokai Univ., Kanagawa, Japan)

High-cadence images taken by the X-Ray Telescope (XRT) aboard Hinode (Solar B), have shown that X-ray jets occur at very high frequency over the polar regions of the Sun. Only the brightest of these explosive events had been previously observed. It is possible that Alfven waves generated by jets contribute greatly to the acceleration of the solar wind; each jet provides a conduit for Alfven waves that add significant energy to the corona by spreading outward from these localized areas on the Sun. Here we explore the manifestations of the jet response in the solar wind using observations from Hinode, the LASCO coronagraph, and from 3D tomographic observations at greater heights above the Sun. We attempt to quantify the jet response in the interplanetary medium from these measurements, and to explore the diminution of this response with solar radius.




2011 SPD Meeting
Las Cruces, NM, June 12 - 16, 2011



The 3D Reconstruction of Heliospheric Density Using Thomson-Scattering Observations – Current Progress and Future Prospects

B.V. Jackson, J. Clover, A. Buffington, P. Hick (UCSD/CASS)

Thomson-scattering observations from the Air Force/NASA Solar Mass Ejection Imager (SMEI) allow a determination of density in the inner heliosphere and its forecast from remote-sensing heliospheric observations. Here we describe our recent attempts to provide density from this technique, and our current success in this endeavour. We would like to provide the best possible measurements of this heliospheric parameter remotely. Here we explore this possibility with the larger amounts of data available from the SMEI imagery that can now be cleaned of auroral signals such that as many as 10,000 lines of sight can be available on each 100-minute orbit to provide these measurements. We speculate on the degree to which these measurements can be used on future heliospheric missions should such instruments provide as finely-calibrated images as those from SMEI.




Royal Astronomical Society National Astronomy Meeting
(RAS/NAM), UK Solar Physics (UKSP) and Magnetosphere,
Ionosphere and Solar-Terrestrial (MIST)
Llandudno, North Wales, UK, April 17-21, 2011



Radio Remote-Sensing Studies of the Inner Heliosphere

M.M. Bisi, R.A. Fallows and A.R. Breen (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, Wales, UK)
E.A. Jensen (ACS Consulting, Houston, TX, USA)
J.M. Clover (UCSD/CASS)
P.K. Manoharan (Radio Astronomy Cntr, National Cntr for Radio Astrophysics, Tata Inst. of Fundamental Research, Udhagamandalam (Ooty), India)
B.V. Jackson (UCSD/CASS)
P.P. Hick (UCSD/CASS an UCSD/SDSC)
J.A. Davies (STFC Rutherford Appleton Lab., Chilton, England, UK)
M.J. Owens (Space Environment Physics Group, Dept of Meteorology, Univ. of Reading, Earley Gate, Reading, England, UK)
S. Hardwick (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, Wales, UK)

Radio remote-sensing observations of the inner heliosphere can be undertaken by both the observation of interplanetary scintillation (IPS) of astronomical radio sources and also the observation of Faraday rotation (FR) of spacecraft or astronomical radio sources. The data sets from various IPS-capable systems are used with the University of California, San Diego (UCSD) three-dimensional (3-D) tomographic-reconstruction and visualisation algorithms. We are able to make comparisons with multi-point {\it in-situ} measurements from various deep-space spacecraft using our reconstruction results. This makes possible the study of structure in the inner heliosphere as a whole as well as the ability to isolate individual features or events such as interplanetary coronal mass ejections (ICMEs) or stream interaction regions (SIRs). FR is the rotation that occurs as an electromagnetic wave traverses a birefringent medium such as the solar corona and inner heliosphere. FR is the integrated product of the electron density and the component of the solar magnetic field parallel to the wave vector of the electromagnetic wave. We will present and discuss the most-recent radio remote-sensing observations of the inner heliosphere using the newly-operational LOw Frequency ARray (LOFAR) as well as those results from other radio-capable systems. We will also investigate the global structure of the heliosphere during the current and previous solar minima using radio-based data primarily, and discuss similarities and differences between the two solar cycles where possible.




217th AAS meeting
Seattle, WA, January 9 - 13, 2011



Analysis of Epsilon Aurigae light curve from the Solar Mass Ejection Imager

J. Clover, B. V. Jackson, A. Buffington, P.P. Hick (UCSD/CASS)
B. Kloppenborg, R. Stencel (Univ. of Denver)

The Solar Mass Ejection Imager (SMEI) was launched aboard the Coriolis spacecraft in 2003. It is equipped with 3 CCD cameras to measure the brightness of Thomson-scattered electrons in the heliosphere. Each CCD images a strip of the sky that is 3°×60°. The three cameras are mounted on the satellite with their fields of view aligned end-to-end so that SMEI sweeps nearly the entire sky each 102 minute orbit. SMEI has now accumulated stellar time series for about 5700 bright stars, including epsilon Aurigae, for each orbit where data is available. SMEI data provide nearly year-round coverage of epsilon Aurigae. The baffled SMEI optics provide more accurate photometric data than ground-based observations, particularly at mid-eclipse when epsilon Aurigae is close to the Sun. We present an analysis of the brightness variations of the epsilon Aurigae system, before and during the eclipse.

The University of Denver participants are grateful for support under NSFgrant 10-16678 and the bequest of William Hershel Womble in support of astronomy at the University of Denver.




2010 AGU Fall Meeting
San francisco, CA, December 13 - 17, 2010



Solar Mass Ejection Imager (SMEI) 3-D reconstructions of CMEs, CIRs and interplanetary shocks, and comparison with in-situ data

B.V. Jackson and J.M. Clover (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
A. Buffington (UCSD/CASS)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)

The Solar Mass Ejection Imager (SMEI) has been operating since February 2003. At the University of California, San Diego (UCSD), a series of editing steps and a tomography program removes zodiacal light, high-energy-particle hits, and aurorae the SMEI data; and generates reconstructed sky-map images and three-dimensional (3-D) volumetric densities shortly after the SMEI CCD images become available. The removal of a long-term base allows us to map the 3-D density extents of coronal mass ejections (CMEs) and co-rotating structures, and measure the density variations of these structures including estimates of their continuity and the extent of density enhancements behind interplanetary shocks. We match our analysis with the in-situ density columns that pass the spacecraft near Earth as well as near the twin Solar TErrestrial RElations Observatory (STEREO) spacecraft. Here we concentrate on Thomson-scattered white-light SMEI observations of the 3 April 2010 halo CME, contrasting it to the studies of previous CME events that provide similar Sun-to-Earth analyses.




Remote-Sensing Studies of Heliospheric Solar-Wind Structure Around Two Solar Minima

M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
J.M. Clover (UCSD/CASS)
A. Breen (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
E.A. Jensen (ACS Consulting, Houston, TX, USA)
R. Fallows (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
B.V. Jackson (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
A. Rawlins (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
J.A. Davies (Space Physics Division, STFC Rutherford Appleton Lab., Didcot, UK)
M. Owens (Dept. of Meteorology, Univ. of Reading, Reading, UK)
M. Xiong (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
A. Buffington (UCSD/CASS)
M. Grande (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)

Remote-sensing observations of the inner heliosphere are carried out routinely using both the interplanetary scintillation (IPS) observations of astronomical radio sources and also the Thomson-scattered white light from heliospheric electrons. For these latter observations, we use the Earth-orbiting Solar Mass Ejection Imager (SMEI: from February 2003) aboard the Coriolis Satellite, and more recently using the Heliospheric Imagers (HIs) aboard the Solar TErrestrial RElations Observatory twin spacecraft (STEREO: from late 2006/early 2007). The data sets from various IPS-capable systems as well as SMEI are used with the University of California, San Diego (UCSD) three-dimensional (3-D) tomographic-reconstruction and visualisation algorithms. We are able to compare with in-situ measurements from multiple spacecraft with these reconstruction results. This makes it possible to study the structure of the inner heliosphere as a whole, including the isolation of individual features or events such as interplanetary coronal mass ejections (ICMEs) or stream interaction regions (SIRs). We look at the global structure of the heliosphere during the current and previous solar minima, and discuss similarities and differences between the two solar cycles where possible.




Type III Metric Radio-Wave Activity Prior to and During Active Region Flaring and CMEs

B.V. Jackson (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
A. Buffington (UCSD/CASS)
D. Oberoi (Haystack Obs., Massachusetts Inst. of Technology, Westford, MA)
L.D. Matthews (Haystack Obs., Massachusetts Inst. of Technology, Westford, MA)

From the time that type III metric radio-wave activity has been known, and imaged, there has been a realization that this activity often increases during, and for some events from a few minutes to several hours prior to the major manifestations observed for a flare or Coronal Mass Ejection (CME). We review these analyses from as long ago as the observations from Culgoora, Australia, and more recently from the French Nancay radio observatory. We find there can be precursor activity before a flare or CME as indicated by the increasing numbers of isolated type III bursts, and that this can be a maximum prior to the most obvious manifestation of either the surface flare or the most obvious rapid outward coronal motion of a CME. Current imaging measurements from the Nancay radio array further clarify the location of this activity for specific events such as the 26 April 2008 CME that was observed just following the Whole Heliosphere Interval (WHI) near the time of solar minimum. A plausible explanation for this precursor activity exists, and we expect that this idea can be more fully tested using present-day observations. As solar activity increases and more observations become available from, for instance, the Murchison Widefield Array (MWA) now under construction in Western Australia, far better worldwide temporal coverage for this type of analysis will exist. In conjunction with current NASA instrumentation such as the Solar TErrestrial RElations Observatory (STEREO) and SOlar and Heliospheric Observatory (SOHO) coronagraphs, and the Solar Dynamics Observatory (SDO), we expect a significant improvement in our understanding of this unique flare and CME precursor activity.




A Heliospheric Imager for Deep Space: Lessons Learned from Helios, SMEI, and STEREO

A. Buffington, B.V. Jackson (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
J.M. Clover (UCSD/CASS)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)

The zodiacal-light photometers on the twin Helios spacecraft, the Solar Mass Ejection Imager (SMEI) aboard the Coriolis spacecraft, and the Heliospheric Imagers (HIs) on the twin Solar-TErrestrial RElations Observatory (STEREO) spacecraft all point the way to optimizing future remote-sensing Thomson-scattering observations from deep space. In the future, such data could be provided by wide-angle viewing instruments deployed on Solar Orbiter, Solar Probe Plus, and other deep-space missions. Here, we present instrument specifications required for a successful heliospheric imager, and the calibration measurements and data-processing steps that enable the best use of these remote-sensing systems. When properly designed and calibrated, data from these types of instruments measure zodiacal-dust properties, and are used to provide three-dimensional reconstructions of heliospheric electron density over large volumes of the inner heliosphere. Such systems measure fundamental properties of the inner heliospheric plasma, provide context for the in-situ monitors on board spacecraft, and perhaps most significantly, enable physics-based analyses of this important segment of the Sun-Spacecraft connection.




Imaging Coronal Mass Ejections and Large-Scale Solar Wind Structure Using IPS and Thomson-Scattered Sunlight

J.M. Clover, B.V. Jackson and A. Buffington (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
M.M. bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth, UK)
M. Tokumaru and K. Fujiki (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)

The Solar Mass Ejection Imager (SMEI) observes Thomson-scattered white light from heliospheric electrons across almost all of the sky nearly all of the time since early 2003. Interplanetary scintillation (IPS) observations of velocity and g-level provide similar structure information but with a less-complete sky-and-time coverage. The Solar TErrestrial RElations Observatory (STEREO) twin spacecraft outer Heliospheric Imagers (HI-2) currently image the heliosphere in Thomson-scattered light near the ecliptic plane far from Earth. The Solar-Terrestrial Environment Laboratory (STELab) IPS observations provide IPS velocity and g-level values, which in conjunction with our tomographic reconstruction program, yield velocities and densities of the inner heliosphere in three dimensions. The same tomographic program substitutes SMEI Thomson-scattering brightness information for the g-level values to derive heliospheric densities from these data alone. We look at the global structure of the heliosphere concentrating mainly on three events from 2007 through the rise phase of Solar Cycle 24. The first event, observed in both the IPS and SMEI defines the three-dimensional velocity and density structure around the time of the shock observed at Earth on 02:02 UT 17 December 2007. The second event, seen only by SMEI, is that of the 23-26 April 2008 coronal mass ejection (CME) and its interplanetary counterpart. The third event is the CME (and its interplanetary counterpart) that took place 17 January 2010 and arrived at STEREO-B about four days later. For each event, we isolate the particular portion of the heliosphere attributed to the transient density structure using our tomographic technique, and then estimate its extent.




SHINE 2010
Santa Fe, New Mexico, July 26 - 30, 2010



UCSD IPS 3-D time-dependent reconstruction of the global solar wind during the last solar minimum

B.V. Jackson, J.M. Clover, P.P. Hick, A. Buffington and N. Amirbekian (CASS/UCSD)

The University of California, San Diego (UCSD) maintains an interplanetary scintillation (IPS) data base from the Solar-Terrestrial Environment Laboratory (STELab), Nagoya, Japan, from the mid-1990’s up to the present. UCSD’s three-dimensional (3-D) reconstruction of these data in time-dependent format is available to provide measurements of global solar wind velocity and density for this entire period with a time cadence of one day when data from STELab are available (generally from April to December each year). Here we concentrate on analyses of measurements obtained during the recent solar minimum, and show time-dependent global solar wind velocity and density in several coordinate formats (e.g., Sun-centered ecliptic and heliographic, and as averaged per Carrington rotation). Velocity and density from these reconstructions are combined to also provide global solar wind dynamic pressure in these same formats. These analyses are used to determine the global extent and change of the solar wind during the last solar minimum. The current UCSD IPS 3-D reconstruction program is now also available for use at the Goddard Spaceflight Community Coordinated Modeling Center (CCMC) for analyses of specific time intervals and ICMEs.




UCSD 3D Reconstruction of the 12 December 2008, 20 January 2009, and 3 April 2010 CMEs

J. Clover, B.V. Jackson, P.P. Hick, A. Buffington and N. Amirbekian (CASS/UCSD)

The Solar Mass Ejection Imager (SMEI) data base is available for the three-dimensional (3-D) reconstruction of CME/ICMEs from early 2003 up through the present. Here we concentrate upon analyses of three events, on 12 December 2008, 20 January 2009, and 3 April 2010; and provide comparisons with in-situ measurements during this interval. The University of California, San Diego (UCSD) SMEI database includes individual full-sky maps and orbit differences that preserve the original instrument resolution and photometric precision. Higher-level products (3-D reconstructions from the data, and 3-D tomographic reconstructed images are also maintained by UCSD on its SMEI website for the entire SMEI period of operation. The SMEI 3-D reconstruction program is now also available for use at the Community Coordinated Modeling Center (CCMC) located at the NASA/Goddard Space Flight Center.




The 13-15 May 2005 CME/ICME/MC: A Comprehensive Study from the Sun to the Earth

M. Bisi, A.R. Breen (Aberystwyth Univ., Wales, UK)
B.V. Jackson (Univ. of California, San Diego, CA, USA)
R.A. Fallows (Aberystwyth Univ., Wales, UK)
A.P. Walsh (Mullard Space Science Laboratory, England, UK)
M.J. Owens (Univ. of Reading, England, UK)
P. Riley and Z. Mikić (Predictive Science, Inc., CA, USA)
A. Gonzalez-Esparza and E. Aguilar-Rodriguez (MEXART, Universidad Nacional Autonoma de Mexico, Mexico)
H. Morgan (Univ. of Hawaii, HI, USA)
A.G. Wood (Aberystwyth Univ., Wales, UK)
E.A. Jensen (ACS Consulting, TX, USA/MMT Observatory, AZ, USA)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Japan)
P.K. Manoharan (Tata Institute of Fundamental Research, Ooty, India)
I.V. Chashei (Pushchino Radio Astronomy Observatory, Moscow Region, Russia)
A.S. Giunta (Univ. of Strathclyde, Scotland, UK/Rutherford Appleton Lab., England, UK)
C.J. Owen (Mullard Space Science Laboratory, England, UK)
K. Fujiki (Solar-Terrestrial Environment Lab., Nagoya Univ., Japan)
J.A. Linker (Predictive Science, Inc., CA, USA)
V.I. Shishov (Pushchino Radio Astronomy Observatory, Moscow Region, Russia) and S.A. Tyul’bashev (Pushchino Radio Astronomy Observatory, Moscow Region, Russia)
G. Agalya (Tata Institute of Fundamental Research, Ooty, India)
S.K. Glubokova (Pushchino Radio Astronomy Observatory, Moscow Region, Russia/Pushchino State Univ., Moscow Region, Russia)
J.M. Clover and P.P. Hick (Univ. of California, San Diego, CA, USA)
B. Pintér (Aberystwyth Univ., Wales, UK). (Institute)

Here, we present a brief overview of the results of a multi-technique, multi-instrument, co-ordinated study of the solar-eruptive and Earth-effective event(s) of 13-15 May 2005. We look at the resulting Earth-directed (halo) coronal mass ejection (CME), the interplanetary counterpart (ICME), and briefly, the flux-rope (Magnetic Cloud – MC) effects on the terrestrial space environment and upper Earth atmosphere. We have combined observations and measurements from coronal and interplanetary remote-sensing instruments, interplanetary and near-Earth in-situ measurements, remote-sensing observations and in-situ measurements of the terrestrial magnetosphere and ionosphere, as well as the use of coronal and heliospheric modelling. These analyses are subsequently used to trace the origin, development, propagation, terrestrial impact, and consequences of this event to obtain the most-comprehensive view (to our knowledge) of an Earth-effective solar eruption to date. Full details of the study of this event can be found in a comprehensive paper by Bisi et al., Solar Physics, Topical Issue (TI) on Remote Sensing of the Inner Heliosphere, 2010, when the TI is published in August/September 2010.




38th COSPAR Scientific Assembly
Bremen, Germany, July 18 - 25, 2010



Solar Mass Ejection Imager (SMEI) near real time images and 3-D reconstruction comparisons with multi-spacecraft observations during the rising phase of Solar Cycle 24

B.V. Jackson, J.M. Clover, P.P. Hick and A. Buffington (UCSD/CASS)
M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., Wales, UK)

The Solar Mass Ejection Imager (SMEI) has been operating since February 2003. At the University of California, San Diego (UCSD) we are now able to provide photometric images from SMEI in near real time. These are available in quick-look form as orbit-to-orbit diㄦence sky maps in a variety of formats. A series of editing steps and a tomography program cleans these data sets of aurora and provides three-dimensional (3-D) volumetric density soon after the images become available, and allows us to map the 3-D density extents of interplanetary coronal mass ejections (ICMEs) and co-rotating structures. Here, we report on observations and 3-D reconstructions from SMEI during the current rising phase of Solar Cycle 24. We match our analyses with in-situ densities from spacecraft near Earth as well as at the two STEREO spacecraft. These include both direct in-situ density variation comparisons and measurements of columnar mass fluxes for different events. These comparisons show the continuity of the structures that match in-situ density measurements at each spacecraft, and their extensions beyond the ecliptic plane.




Changes in Gegenschein brightness with time, recorded by the Solar Mass Ejection Imager (SMEI)

A. Buffington, B.V. Jackson, P.P. Hick and J.M. Clover (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI), operating since February 2003, has provided photometric-quality visible-light maps covering nearly the entire sky, at a rate of roughly 15 per day for more than seven years. To measure the Gegenschein and characterize other aspects of the zodiacal light, we combine these maps into daily averages after subtracting individual bright stars, a residual sidereal background, and finally an empirical zodiacal-light model. From averages of the yearly brightness over the seven-year period, we find that the Gegenschein brightness has been steadily decreasing by about 2 percent per year. To confirm that this observation does not result from an error in assessing the change in imager response over this time, we also search for a potential brightness change of three comparably-bright but presumably unchanging sidereal objects, the Andromeda Galaxy and the two Magellanic Clouds. We find the brightness of these remains constant over this seven-year time period to better than 1 percent.




Asia Oceania Geosciences Society (AOGS) 2010)
Hyderabad, Andhra Pradesh, India, July 5 - 9, 2010



Reconstructions of the solar wind structure in the inner heliosphere and at the inner planets

M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
B.V. Jackson (UCSD/CASS, USA)
A.G. Wood (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
J.M. Clover (UCSD/CASS, USA)
A.R. Breen and R.A. Fallows (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
E.A. Jensen (ACS Consulting, Houston, TX; MMT Observatory, Mt. Hopkins, Amado, AZ, USA)
M. Tokumaru and K. Fujiki (Solar-Terrestrial Environment Lab., Univ. of Nagoya, Nagoya, Japan)
P.P. Hick (UCSD/CASS; UCSD/SDSC, USA)
A. Buffington (UCSD/CASS, USA)

We are able to reconstruct the inner heliosphere in three dimensions through the use of a Computer Assisted Tomography (C.A.T.) algorithm which incorporates a kinematic solar-wind model. This C.A.T. technique can use multiple lines of sight from either observations of interplanetary scintillation (IPS) or Thomson-scattered white-light brightness from the Solar Mass Ejection Imager (SMEI), or both of these as input. We present an overview of results of inner-heliosphere reconstructions along with evaluations of density and/or velocity at various points in the inner heliosphere such as the inner planets and deep-space spacecraft. Various large-scale features can be reconstructed, such as interplanetary coronal mass ejections (ICMEs), co-rotating features, and also the fast and slow solar wind streams.




Reconstructions of the solar wind over two separate solar minima

M.M. Bisi (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
B.V. Jackson (UCSD/CASS, USA)
M.J. Owens (Inst. of Mathematics and Physics, Aberystwyth Univ., UK
J.M. Clover (UCSD/CASS, USA)
A.R. Breen and R.A. Fallows (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
P.P. Hick (UCSD/CASS; UCSD/SDSC, USA)
M. Tokumaru and K. Fujiki (Solar-Terrestrial Environment Lab., Univ. of Nagoya, Nagoya, Japan)
A. Buffington (UCSD/CASS, USA)

We present results of three-dimensional (3-D) reconstructions of the inner heliosphere at two different solar minima. We investigate the gross structure in both density and velocity reconstructions for the present, seemingly-elongated, Solar Cycle 23-24 minimum, and compare these with that of the previous Solar Cycle 22-23 minimum (which may have occurred during a time of grand maxima). Where possible, since we are able to evaluate density and velocity values at any place within the 3-D reconstructed volume, we will compare our density and velocity results with spacecraft in-situ measurements based both near the Earth and elsewhere in the inner heliosphere. We will concentrate primarily on reconstructed interplanetary scintillation (IPS) data (since these are available from both solar minima), but we will also incorporate Solar Mass Ejection Imager (SMEI) Thomson-scattered brightness data where possible for the present solar minimum.




Royal Astronomical Society National Astronomy Meeting
(RAS/NAM), UK Solar Physics (UKSP) and Magnetosphere,
Ionosphere and Solar-Terrestrial (MIST)
Glasgow, Scotland, UK, April 12-16, 2010



A comprehensive study of the 13-15 May 2005 solar event(s)

M.M. Bisi and A.R. Breen (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
B.V. Jackson (UCSD/CASS, USA)
R.A. Fallows (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
A.P. Walsh (Mullard Space Science Lab., Univ. College London, England, UK)
M.J. Owens (Inst. of Mathematics and Physics, Aberystwyth Univ., UK)
Z. Mikic and P. Riley (Predictive Science, Inc., San Diego, CA, USA)
C.J. Owen ((Mullard Space Science Lab., Univ. College London, England, UK)
A. Gonzalez-Esparza (Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Morelia Mich, Mexico
A.G. Wood (Inst. of Mathematics and Physics, Aberystwyth Univ., UK
E. Aguilar-Rodriguez (Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Morelia Mich, Mexico
H. Morgan (Inst. for Astronomy, Univ. of Hawaii, Honolulu, HI, USA)
E.A. Jensen (ACS Consulting, Houston, TX; MMT Observatory, Mt. Hopkins, Amado, USA)
M. Tokumaru (Solar-Terrestrial Environment Lab., Univ. of Nagoya, Nagoya, Japan)
P.K. Manoharan (Radio Astronomy Centre, National Centre for Radio Astrophysics, Tata Inst. of Fundamental Research, Udhagamandalam (Ooty), India)
K. Fujiki (Solar-Terrestrial Environment Lab., Univ. of Nagoya, Nagoya, Japan)
I.V. Chashei (Pushchino Radio Astronomy Obs., Astrospace Center, Lebedev Physical Inst., Moscow region, Russia)
A.S. Gunta (Dep. of Physics, Univ. of Strathclyde, Glasgow; Space Science and Technology Dep., Rutherford Appleton Lab., Didcot, UK)
J.A. Linker (Inst. of Mathematics and Physics, Aberystwyth Univ., UK
V.I. Shishov and S.A. Tyul'bashev (Pushchino Radio Astronomy Obs., Astrospace Center, Lebedev Physical Inst., Pushchino, Russia)
G. Agalya (Radio Astronomy Centre, National Centre for Radio Astrophysics, Tata Inst. of Fundamental Research, Udhagamandalam (Ooty), India)
S.K. Glubokova (Pushchino Radio Astronomy Obs., Astrospace Center, Lebedev Physical Inst., Pushchino; Pushchino State Univ., Pushchino, Russia, Russia)
P.P. Hick (UCSD/CASS; UCSD/SDSC, USA)
J.M. Clover (UCSD/CASS, USA)
B. Pintër (nst. of Mathematics and Physics, Aberystwyth Univ., Aberystwyth. UK)
A. Buffington (UCSD/CASS, USA)

We present an overview of the results of a multi-technique, multi-instrument, co-ordinated study of the solar-eruptive event of 13 May 2005 and its progression through the inner heliosphere. We have combined observations and measurements from coronal and interplanetary remote-sensing instruments, interplanetary and near-Earth in-situ measurements, remote-sensing observations and in-situ measurements of the terrestrial magnetosphere and ionosphere, along with coronal and heliospheric modelling. We discuss the resultant Earth-directed (halo) coronal mass ejection (CME), and briefly, the effects on the terrestrial space environment and upper Earth atmosphere. These analyses are used to trace the origin, development, propagation, terrestrial impact, and subsequent consequences of this event to obtain the most-comprehensive view of a geo-effective solar eruption to date. Full details of the study of this event can be found in Bisi et al., Solar Physics, Topical Issue (TI) on Remote Sensing of the Inner Heliosphere, 2010, when the TI is published.




9th Annual International Astrophysics Conference:
Pickup Ions Throughout the Heliosphere and Beyond
Maui, HI, March 14 - 19, 2010



3-D reconstruction of the inner heliosphere: a global solar wind boundary from remote-sensing data

B.V. Jackson, P.P. Hick, A. Buffington and J. Clover (UCSD/CASS)

Observations of the inner heliosphere have been carried out on a routine basis using interplanetary scintillation (IPS) for more than two decades, and from the Solar Mass Ejection Imager (SMEI) since its launch in early 2003. These remote-sensing data have been used to measure and reconstruct three-dimensional (3-D) solar wind structure throughout this time period. These global analyses, especially from Solar-Terrestrial Environment Laboratory (STELab) IPS observations, provide an inner boundary in density and velocity that is nearly complete over the whole heliosphere for the major part of the year with a time cadence of about one day. By using the IPS velocity analyses we are able to convect-outward solar surface magnetic fields measured during these periods in order to provide measurements of the field throughout the global volume. In the inner heliosphere these 3-D analyses of density, velocity, and vector magnetic field have been compared successfully with in-situ measurements obtained near Earth, STEREO, Mars, and at the Ulysses spacecraft. These provide a precise inner time-dependent boundary for these parameters that can be extrapolated outward to the edge of the heliosphere using current 3-D MHD modelling techniques. We present this boundary for recent IPS data, and we show its potential for extending these parameters globally to the edge of the heliosphere.




2009 AGU Fall Meeting
San Francisco, CA, December 14 - 18, 2009



About the Solar Mass Ejection Imager (SMEI) 3D-Reconstruction-and-Display of Co-rotating Heliospheric Structure during the Present Deep Solar Minimum

B.V. Jackson and M.M. Bisi (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
A. Buffington and J.M. Clover (UCSD/CASS)

Observations of the inner heliosphere from the Solar Mass Ejection Imager (SMEI) since its launch in early 2003 have been used to measure and map the outward flow of over 300 coronal mass ejections (CMEs). Here, we report on observations and three-dimensional (3D) reconstructions of co-rotating heliospheric structures observed by SMEI during the present deep solar minimum. There is little evidence of large, continuous density structures that co-rotate over the long term (for durations of several weeks) throughout this solar minimum time period. We compare the SMEI evidence of co-rotating density structures with 3D reconstructions of interplanetary scintillation (IPS) velocity observations, and generally with in-situ solar wind measurements from the SOHO, Wind, ACE, and twin STEREO spacecraft. If we define co-rotating heliospheric structure by these in-situ measurements or by the IPS 3D-reconstruction velocity analyses, a general pattern emerges for co-rotating heliospheric density structure in Thomson-scattering observations. The density enhancements shown in brightness difference images that co-rotate and that emanate from specific regions on the Sun appear to expand to a far larger extent than a single heliospheric current sheet region, or than the standing density structures near their origin on the solar surface.




Coronal Mass Ejections in the Declining and Minimum Phase between Solar Cycles 23 and 24

M.M. Bisi, B.V. Jackson and J.M. Clover (UCSD/CASS)
M. Tokumaru (STELab, Nagoya Univ., Nagoya, Japan)
A. Buffington (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
K. Fujiki (STELab, Nagoya Univ., Nagoya, Japan)

The Solar Mass Ejection Imager (SMEI) observes Thomson-scattered white light from heliospheric electrons across the sky all the time, and observes heliospheric structure throughout a large portion of the inner heliosphere all year round. Interplanetary scintillation (IPS) observations of velocity and g-level provide similar structure information but with sky and temporal coverage which is generally less complete. We have used Solar-Terrestrial Environment Laboratory (STELab) IPS observations to provide IPS velocity and g-level values (a proxy for density), in conjunction with our three dimensional (3D) tomographic reconstruction program, to yield velocities and densities of the inner heliosphere out to around 3 AU. A second determination substitutes SMEI brightness information for the g-level values to derive the heliospheric density. We look at the global structure of the heliosphere throughout this time, concentrating on two time intervals from 2008 (in the declining phase of solar cycle 23). The first interval includes the 23-26 April 2008 coronal mass ejection (CME) and its interplanetary counterpart seen best in SMEI data. The second interval includes a CME (and its interplanetary counterpart) that took place 02-06 June 2008. We try to isolate the particular portion(s) of the heliosphere attributed to each event, and then estimate their masses. We also compare our results with the STEREO Heliospheric Imager data where possible.




Measurements of Zodiacal-light brightness from the Solar Mass Ejection Imager (SMEI)

A. Buffington, M.M. Bisi, J.M. Clover, P.P. Hick and B.V. Jackson (UCSD/CASS)

Observations from the Solar Mass Ejection Imager (SMEI), now spanning over 6 years, provide unprecedented near-full-sky photometric maps each 102-minute orbit, using data from 3 unfiltered CCD cameras. SMEI’s 0.1% photometric precision enables observation of heliospheric structures with surface brightness down to several S10’s (an S10 is the equivalent brightness of a 10th magnitude star spread over one square degree). When individual bright stars and an empirical residual sidereal background are removed from the maps, the residue is dominated by the zodiacal light (ZL). The present work combines individual SMEI sky maps to produce daily average maps, and uses the sequence of these for both an empirical characterization of the ZL and an investigation of its variation over time scales from several days to several years.




The 26 April 2008 CME; a Case Study Tracking a CME into the Heliosphere

D.F. Webb (ISR, Boston College, Chestnut Hill, MA, USA)
A.B. Galvin (EOS, Univ. of New Hampshire, Durham, NH, USA)
N. Gopalswamy (NASA Goddard Space Flight Ctr., Greenbelt, MD, USA)
T.A. Howard (Southwest Research Institute, Boulder, CO, USA)
A.A. Reinard (NOAA Space Weather Prediction Ctr., Boulder, CO, USA)
B.V. Jackson (CASS, Univ. of California - San Diego, La Jolla, CA, USA)
C. Davis ( Space Science and Technology Dept., Rutherford Appleton Lab., Chilton, UK)

With the current unique constellation of spacecraft, we are studying the origins of CMEs, their 3D structure and how they propagate through the heliosphere. Here we present the results of a case study of one well observed event that occurred during the Whole Heliosphere Interval (WHI), originating at the Sun on 26 April 2008. The event arose from a cluster of 3 active regions that evolved over several solar rotations centered on WHI. The CME was moderately fast with evidence of a shock and was associated with a coronal arcade, coronal dimming and an EUV wave. The April 26 CME originated from disk center for STEREO-B and apparently caused a small SEP event and shock and possible magnetic cloud at STEREO-B on April 29. A brief IP type II suggests that this event had the lowest starting frequency ever observed, which has implications for the medium through which the shock propagates. Possible ejecta was detected in situ at STEREO-B. The Fe charge states suggest that there was a CIR-type interface with some bidirectional electron streaming present. This is confirmed by SMEI 3D reconstructions of density indicating that the ICME interacted with a preexisting CIR. The ICME was also imaged by the SECCHI HI imagers; both the SMEI and HI data permit us to track the dense material from the Sun past 1 AU.




Whole Heliosphere Interval: Second WHI Workshop
Boulder, CO, November 10 - 13, 2009



A Summary of Three-Dimensional Reconstructions of the Whole Heliosphere Interval Using STELab IPS Data

M.M. Bisi, B.V. Jackson and J.M. Clover (UCSD/CASS)
P. Hick (UCSD/CASS and UCSD/SDSC)
M. Tokumaru (STELab, Nagoya Univ., Nagoya, Japan)
A. Buffington and S. Hamilton (UCSD/CASS)
K. Fujiki (STELab, Nagoya Univ., Nagoya, Japan)

Interplanetary scintillation (IPS) is the rapid variation in radio signal from a compact distant natural radio source produced by turbulence and variations in the solar-wind density. We use a time-dependent three-dimensional (3D) Computer-Assisted Tomography (C.A.T.) algorithm incorporating a kinematic solar-wind model in order to reconstruct the inner heliosphere (out to a distance of 3 AU) in three dimensions for both density and velocity solar-wind parameters. The IPS data used here are taken from the Solar-Terrestrial Environment Laboratory (STELab) IPS arrays based in Japan and operated by Nagoya University at the Toyokawa laboratory. We present an overview and synopses of these 3D C.A.T. reconstructions for the Whole Heliosphere Interval (WHI) when STELab IPS data were available, and comment on the context of this period in relation to other periods during this current and seemingly elongated solar minimum activity. The WHI covers Carrington Rotation 2068 (CR2068) and for the Earth’s perspective using synodic rotation continues in time from 00:27 UT on 20 March 2008 through to 07:19 UT on 16 April 2008. The synodic (or Carrington) rotation period of the Sun is 27.28 days, while the sidereal rotation period is 25.38 days.




SMEI Three-Dimensional Reconstructions and Analysis of the Whole Heliosphere Interval

B.V. Jackson (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
A. Buffington, M.M. Bisi, J.M. Clover and M.S. Hamilton (UCSD/CASS)
J.A. Davies and S.R. Crothers (Space Sciences and Technology Cntr, Rutherford Appleton Lab., Didcot, UK)

The Solar Mass Ejection Imager (SMEI) measures Thomson-scattered brightness from Earth Orbit. We use a time-dependent three-dimensional (3D) Computer-Assisted Tomography (C.A.T.) algorithm incorporating a kinematic solar-wind model to reconstruct the density structure in the inner heliosphere from these brightness observations. We present an overview and synopses of these analyses for the Whole Heliosphere Interval (WHI), and comment on the context of this period in relation to other periods during the current and seemingly-elongated period of solar-minimum activity. The WHI covers Carrington Rotation 2068 (CR2068), and for this period we construct J-maps (elongation-time plots at a fixed position angle) of the brightness differences from SMEI 3D-reconstructed images. These maps provide a synopsis of the structures present during the WHI, and also a method to compare with similar J-maps obtained from the Solar TErrestrial RElations Observatory (STEREO) Heliospheric Imagers for the same time intervals. There are many CME-like structures and only a few corotating structures observed in both the SMEI and STEREO analyses during the WHI. The corotating structures are neither as numerous nor as dominant as in some Carrington rotations around the WHI.




ILWS 2009 Meeting
Ubatuba, Sao Paulo, Brazil, October 4 - 7, 2009



The Solar Mass Ejection Imager (SMEI) 3D-reconstruction of density enhancements behind interplanetary shocks
B.V. Jackson, P.P. Hick, A. Buffington, M.M. Bisi, J.M. Clover, S. Hamilton (UCSD/CASS)

M. Tokumaru and K. Fujiki (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)

The Solar Mass Ejection Imager (SMEI) observes the increased brightness from the density enhancements behind interplanetary shocks that are observed in situ near the Earth. We use the University of California at San Diego (UCSD) time-dependent 3D-reconstruction technique to map the extents of these density enhancements. As examples, we examine the shock density enhancements associated with several well-known coronal mass ejections (CMEs) including that of the 28 October 2003 (Halloween storm) event, the 20 January 2005 CME-induced shock, and the shock observed following the CME of 13 December 2006. We compare these density enhancements with reconstructed velocity observations from STELab interplanetary scintillation (IPS) measurements when these are available. The analyses from these and additional SMEI-observed events show that the shock response density increase is generally not a continuous broad front surrounding the CME driver, and that within analysis errors the UCSD 3D-reconstructions determine shock densities from remotely-observed brightness that match those observed in situ.




Coronal Mass Ejections and Large-Scale Solar Wind Structure in the Declining and Minimum Phase between Solar Cycles 23 and 24

M. M. Bisi, B.V. Jackson, J.M. Clover (UCSD/CASS)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)
A. Buffington (UCSD/CASS)
P.P. Hick (UCSD/CASS and UCSD/SDSC)
K. Fujiki (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)

The Solar Mass Ejection Imager (SMEI) observes Thomson-scattered white light from heliospheric electrons across almost all of the sky nearly all of the time; thus it observes heliospheric structure throughout much of the inner heliosphere all year round. Interplanetary scintillation (IPS) observations of velocity and g-level provide similar structure information but with a less-complete sky and time coverage. We have used Solar-Terrestrial Environment Laboratory (STELab) IPS observations to provide IPS velocity and g-level values, in conjunction with our tomographic reconstruction program, to yield velocities and densities of the inner heliosphere in three dimensions. A second determination substitutes SMEI brightness information for the g-level values to derive heliospheric densities. We look at the global structure of the heliosphere at this time concentrating mainly on two events from 2008 (still in the declining phase of cycle 23). The first event, seen only by SMEI, is that of the 23-26 April 2008 coronal mass ejection (CME) and its interplanetary counterpart. The second is the CME(and its interplanetary counterpart) that took place 02-06 June 2008. For each event, we attempt to isolate the particular portion of the heliosphere attributed to the transient using our tomographic technique, and then estimate its mass.




SOHO-23: Understanding a Peculiar Solar Minimum
Northeast Harbor, Maine, September 21 - 25, 2009



SMEI and IPS remote sensing and 3D reconstruction of corotating heliospheric structures during solar minimum

B.V. Jackson, M.M. Bisi, P.P. Hick, A. Buffington and J.M. Clover (UCSD/CASS, La Jolla, CA)
D.F. Webb (ISR, Boston College, Chestnut Hill, MA)

Observations of the inner heliosphere from the Solar Mass Ejection Imager (SMEI) since its launch in early 2003 have been used to measure and map the outward flow of over 300 coronal mass ejections (CMEs). Here we report on observations and 3D reconstructions of corotating heliospheric structures and CMEs observed by SMEI during the current solar minimum. In these observations and 3D-reconstructions at this solar minimum, there is little evidence of density structures that corotate over the long-term (for durations of several weeks). We compare the SMEI evidence we have of corotating density structures with 3D-reconstructions of interplanetary scintillation (IPS) velocity observations from the Solar-Terrestrial Environment Laboratory (STELab), Nagoya University, Japan. From these analyses we can extract both solar wind density and velocity to compare with ground truth multi-point, in-situ solar wind measurements from the SOHO, Wind, ACE, and the STEREO spacecraft. If we define corotating heliospheric structures by in-situ measurements or by the 3D velocity analyses, the dense structures preceding and following these regions generally appear discontinuous in radial extent from near the Sun out to 1 AU.

PPT Poster


Tracking CMEs from the Sun into the heliosphere during the WHI period

D.F. Webb (ISR, Boston college, Chesnut Hill, MA)
A. Galvin (Univ. of New Hampshire, Durham, NH)
N. Gopalswamy (NASA Goddard Space Flight Ctr., Greenbelt, MD)
D. Haber (ILA, Univ. of Colorado, Boulder, CO)
P. McIntosh (Heliosynoptics, Inc., Boulder, CO)
B.V. Jackson and M.M. Bisi (UCSD/CASS, La Jolla, CA)
S.P. Plunkett (SSL, Naval Research Lab., Washington, DC)

The Whole Heliosphere Interval (WHI) is an internationally coordinated observing and modeling effort to characterize the 3-dimensional interconnected solar-heliospheric-planetary system. WHI observing campaigns began with the 3-D solar structure from solar Carrington Rotation 2068, which ran from March 20 - April 16, 2008. One of the working groups is concerned with the effect of transient activity on the quiet heliosphere. We report on progress of this WHI working group on transients. Our overarching goal is to trace the effects of solar structure and activity through the solar wind to the Earth, other planets and spacecraft. Specific projects involving data during the WHI interval are the origins/initiation of CMEs including associated active regions and filaments/prominences, using multi-spectral data to study transients over large distances (from Sun), and analyses of specific events. A summary of some of the key results so far from the WHI transients working group, including from the recent IAU JD16 meeting in August 2009, will be given.




Whole Heliosphere Interval
XXVII IAU General Assembly Joint Discussion JD16
Rio de Janeiro, Brazil, August 12 - 14, 2009



3D reconstructions of the Whole Heliosphere Interval and comparison with in-ecliptic solar wind measurements from STEREO, ACE and Wind instrumentation

M.M. Bisi, B.V. Jackson, J.M. Clover, P.P. Hick, A. Buffington (UCSD/CASS)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Japan)

We present results from simultaneous Interplanetary Scintillation (IPS) and STEREO measurements/observations using 3D reconstructions from the Solar-Terrestrial Environment Laboratory (STELab) of the Whole Heliosphere Interval (WHI) - Carrington rotation 2068 (CR2068). This is part of the world-wide IPS community's International Heliosphysical Year (IHY) collaboration. We show the structure of the inner heliosphere during this time and how our global reconstructions compare with in-ecliptic deep-space spacecraft measurements such as those taken by Wind and the twin STEREO spacecraft. These 3D tomographic reconstructions of the inner heliosphere have been successfully used for over a decade to visualize and investigate the structure of the solar wind and its various features such as transients and co-rotating regions.




Tracking CMEs from the Sun into the heliosphere during the WHI period

D. F. Webb (Inst. for Scientific Research, Boston College, MA)
A. Galvin (Space Science Ctr., Univ. of New Hampshire, Durham, NH)
N. Gopalswamy (NASA Goddard Space Flight Ctr., Greenbelt, MD)
D. Haber (ILA, Univ. of Colorado, Boulder, CO)
P. McIntosh (Heliosynoptics, Inc., Boulder, CO)
B.V. Jackson and M.M. Bisi (UCSD/CASS, La Jolla, CA)
S.P. Plunkett (SSL, Naval Research Lab., WA, DC)

Abstract not available




SMEI remote sensing and the 3D reconstruction of corotating heliosheric structures during WHI

B.V. Jackson, M.M. Bisi, P.P. Hick, A. Buffington and J.M. Clover (UCSD/CASS, La Jolla, CA)
D.F. Webb (Inst. for Scientific Research, Boston College, Chestnut Hill, MA)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)

Observations of the inner heliosphere have been carried out on a routine basis by SMEI since its launch in early 2003, and these have been used to measure and map the outward flow of several-hundred CMEs. By employing a kinematic model of the solar wind, we reconstruct three-dimensional (3D) solar wind structures from multiple observing lines of sight through the outward-flowing solar wind. Here we report on observations and 3D reconstructions of corotating heliospheric structures and CMEs observed by the Solar Mass Ejection Imager (SMEI) during the Whole Heliosphere Interval (WHI). At UCSD we provide measurements of heliospheric structures relative to a long-term base, and even in these observations and 3D-reconstructions during the WHI near solar minimum there is little evidence of long-term stationary-standing density structures that corotate. By including interplanetary scintillation (IPS) velocity observations from STELab, Japan we can extract both the solar wind density and velocity from these analyses to compare with “ground truth” measurements from multi-point, in-situ solar wind measurements from the STEREO, SOHO, Wind, and the ACE spacecraft. We define the heliospheric structures by these 3D velocity analyses, and they show that while the velocities map large regions near the ecliptic that to some extent corotate during the WHI, the dense structures that front and follow these regions are far more tenuous.




End-to-end observations and modeling of Whole Heliosphere Interval: Origins and impacts of high-speed streams

S.E. Gibson (NCAR, High Altitude Obs., Boulder, CO)
C.N. Arge (Air Force Research Lab, VSBXS, Hanscom AFB, MA)
M.M Bisi and J.M. Clover (UCSD/CASS)
G. de Toma and B. Emery (NCAR, High Altitude Obs., Boulder, CO)
A. Galvin (Space Science Ctr., Univ. of New Hampshire, Durham, NH)
N. Gopalswamy (NASA Goddard Space Flight Ctr., Greenbelt, MD, USA)
J. Gosling (Los Alamos National Lab., Los Alamos, NM
D. Haber (ILA, Univ. of Colorado, Boulder, CO)
P.P Hick and B.V. Jackson (UCSD/CASS)
J.U. Kozyra (Univ. of Michigan, Ann Arbor, MI)
R.J. Leamon (ADNET Systems, NASA/GSFC, Greenbelt, MD)
J. Lei (Dept. of Aerospace Engineering Sciences, Univ. of Colorado, Boulder, CO)
P.K. Manoharan (Radio Astronomy Centre, NCRA, Tata Inst. of Fundamental Research, Ooty, India)
P.S McIntosh (Heliosynoptics, Inc., Boulder, CO)
S. McIntosh (NCAR/HOA, Boulder, CO
T. Onsager (NOAA, Space Environment Ctr., Boulder, CO)
G. Petrie (NSO, Tucson, AZ)
S. Plunkett (SSL, Naval Research Lab., WA, DC)
L. Qian (NCAR, High Altitude Obs., Boulder, CO
A.A. Reinard (NOAA Space Weather Prediction Ctr., Boulder, CO
P. Riley (Predictive Science, Inc., San Diego, CA)
P. Schroeder (Space Sciences Lab., Univ. of California Berkeley, Berkeley, CA
S. Solomon (NCAR, High Altitude Obs., Boulder, CO
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Japan)
B.J. Thompson (Lab. for Solar and Space Physics, NASA/GSFC, Greenbelt, MD
D.F. Webb (Inst. for Scientific Research, Boston College, MA)

Abstract not available

PDF Poster



SHINE 2009
Wolfville, Nova Scotia, Canada, August 3 - 7, 2009



The UCSD Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS) 3D reconstruction analyses and databases now at the CCMC

B.V. Jackson, M.M. Bisi, J.M. Clover, P.P. Hick and A. Buffington (UCSD/CASS, La Jolla, CA)

Both the Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS) data bases and 3D modeling are now available and operate at the Community Coordinated Modeling Center (CCMC). We present the current state of these instrument’s databases that are maintained and stored on UCSD/CASS Web servers. The IPS database is available for real-time access from the Solar-Terrestrial Environment Laboratory (STELab), Japan, and the UCSD IPS Web site provides a variety of higher-level data products derived from these observations to help in Space Weather Forecasting. The up-to-date UCSD SMEI database includes individual SMEI CCD data frames from each of the three SMEI cameras since first light in February 2003, as well as full-sky maps in a sidereal reference frame that preserve the original instrument resolution and photometric precision. Higher-level products from this database and 3-D tomographic reconstruction images are also maintained by UCSD on its SMEI website for the entire SMEI operation interval.




The large-scale structure of the solar wind during solar minimum conditions using three-dimensional reconstructions of interplanetary scintillation data

M.M. Bisi, B.V. Jackson and J.M. Clover (UCSD/CASS, La Jolla, CA)
M. Tokumaru and K. Fujiki (STELab, Nagoya Univ., Nagoya, Japan)
A.R. Breen and R.A. Fallows (Inst. of Mathematical and Physical Sciences, Aberystwyth Univ., Wales, UK)
A. Buffington and P.P. Hick (UCSD/CASS, La Jolla, CA)

Interplanetary scintillation (IPS) observations provide information about a large portion of the inner heliosphere. We use Solar-Terrestrial Environment Laboratory (STELab) IPS velocity and g-level observations as well as IPS velocity observations from the European Incoherent SCATter (EISCAT) and EISCAT Svalbard Radar (ESR), with our three-dimensional (3D) reconstruction data processing to determine velocities and densities of the inner heliosphere. Here, we concentrate primarily on results covering the 2007-2009 International Heliophysical Year (IHY) which includes the Whole Heliosphere Interval (CR2068). We present these using various forms of imaging from our time-dependent modelled calculations that can measure changes with durations of less than a day, and compare these with various spacecraft in-situ measurements. We also present synoptic maps from the reconstructions. These maps show large-scale solar wind structure during the somewhat unusual solar-minimum conditions, in relation to transients that are present during this period. These maps are also available as differences relative to a Carrington-averaged background.




Measurements of white-light images of comet plasma tails as a proxy for solar wind speed

J.M. Clover, M.M. Bisi, A. Buffington, B.V. Jackson and P.P. Hick (UCSD/CASS, La Jolla, CA)

The high temporal and spatial resolution of heliospheric white-light imagers enables us to measure the changes in plasma tails of bright comets. Plasma tails of comets have been recognized as natural probes of the solar wind for many years, and thus using the technique developed at the University of California, San Diego to measure the changes in the plasma tails of comets, we obtain measurements for the speed of the solar wind in situ. We present the results of this technique used successfully on multiple comets observed by the Solar Mass Ejection Imager (SMEI) and Heliospheric Imagers on board the twin Solar TErrestrial RElations Observatory (STEREO) spacecraft, and discuss future applications.




Solar Wind 12, 12th International Solar Wind Conf.
Saint-Malo, France, June 21 - 26, 2009



The Solar Mass Ejection Imager (SMEI) 3D-reconstruction of density enhancements behind interplanetary shocks

B.V. Jackson, P.P. Hick, A. Buffington, M.M. Bisi and J.M. Clover (UCSD/CASS, La Jolla, CA)
M. Tokumaru and K. Fujiki (STELab, Nagoya Univ. Nagoya, Japan)

The Solar Mass Ejection Imager (SMEI) observes the increased brightness from the density enhancements behind interplanetary shocks that are observed in situ near the Earth. We use the UCSD time-dependent 3D-reconstruction technique to map the extents of these density enhancements in 3D. As examples, we examine the shock density enhancements associated with several well-known coronal mass ejections (CMEs) including those on 28 October 2003 (Halloween storm), and on 20 January 2005. We compare these with reconstructed velocity measurements from STELab interplanetary scintillation (IPS) observations when these are available. The SMEI analyses are used to certify that the brightness enhancements observed are in direct response to the plasma density enhancements that are also measured in situ.




Large-scale heliospheric structure during solar-minimum conditions using a 3D time-dependent reconstruction solar-wind model and STELab IPS observations

M.M. Bisi, B.V. Jackson and J.M. Clover (UCSD/CASS, La Jolla, CA)
M. Tokumaru and K. Fujik (STELab, Nagoya Univ., Nagoya, Japan)

Interplanetary scintillation (IPS) observations provide information about a large portion of the inner heliosphere. We have used STELab IPS velocity and g-level observations with our 3D-reconstruction model to determine velocities and densities of the inner heliosphere in three dimensions. We present these observations using synoptic maps from our time-dependent model that can measure changes with durations of less than one day. These synopses show large-scale stable solar-wind structure during solar-minimum conditions in relation to transients that are present during this period. These are also available as differences relative to the background. Here, we concentrate primarily on data covering the 2007-2009 International Heliophysical Year (IHY) which includes the Whole Heliosphere Interval (CR2068).




Interactions structures in the solar wind: IPS and STEREO HI observations

G.D. Dorrian, A.R. Breen, I. Whittaker and M. Grande (Inst. of Mathematical and Physical Sciences, Aberystwyth Univ., Aberystwyth, Wales, UK
J.A. Davies (The Space Science and Technology Dept., Science and Technology Facilities Council, Rutherford-Appleton Lab., Didcot, England, UK
A.P. Rouillard (Space Environment Physics, School of Physics and Astronomy, Univ. of Southampton, Highfield, England, UK)
M.M. Bisi (UCSD/CASS, La Jolla, CA, USA)
R.A. Fallows (Inst. of Mathematical and Physical Sciences, Aberystwyth Univ., Aberystwyth, Wales, UK)

We report results from simultaneous long-baseline interplanetary scintillation (IPS) and Solar TErrestrial RElations Observatory (STEREO) Heliospheric Imager (HI) observations of interacting structures in the solar wind. The combination of high-resolution observations of small-scale structure from IPS and the global overview of HI allows the IPS observations to be interpreted in the light of their position in the large-scale structure, something which has not been possible with this degree of accuracy before. The results presented include coronal mass ejection (CME) cannibalisation and a small-scale solar wind transient entrained within the compression region of a co-rotating interaction region, as well as showing solar wind structures which impacted on the Venus ionosphere. We also present evidence of rapid variability in the solar wind in the aftermath of a CME and suggest these as a driver for continued comet-tail activity.




AAS/SPD 2009
Boulder, CO, June 14 - 18, 2009



3D-Reconstruction of Density Enhancements Behind Interplanetary Shocks from Solar Mass Ejection White-Light Observations

B.V. Jackson, P.P. Hick, A. Buffington, M.M. Bisi and J.M. Clover (UCSD/CASS)
M. Tokumaru and K. Fujiki (Solar-Terrestrial Environment Lab., Nagoya Univ., Japan)

The Solar Mass Ejection Imager (SMEI) observes the increased brightness from the density enhancements behind interplanetary shocks that are observed in situ near the Earth. We use the University of California, San Diego time-dependent three-dimensional-reconstruction technique to map the extents of these density enhancements. As examples, we examine the shock density enhancements associated with several well-known coronal mass ejections including the 28 October 2003 (Halloween storm) event. We compare these density enhancements with reconstructed velocity observations from Solar-Terrestrial Environment Laboratory interplanetary scintillation (IPS) observations when these are available. Volumetric-differencing techniques available from the SMEI analyses show that the outer portion of a larger increase in heliospheric density is often what is observed in short-time image brightness subtractions from these data.




CMEs In The Heliosphere Observed With Combined Imaging And In-situ Data From LASCO, Stereo And SMEI

D.F. Webb (Boston College)
D. Biesecker (NOAA Space Weather Prediction Cente)
T.A. Howard (Air Force Research Lab., National Solar Observatory)
J.G. Luhmann and Y. Li (Space Sciences Lab., Univ. of California- Berkeley)
A. Galvin (Univ. of New Hampshire)
R.A. Howard (Naval Research Lab., Space Sciences Div.)
B.V. Jackson (CASS, Univ. of California, San Diego)

Despite being in solar activity minimum, there have been a number of events in which a CME observed at the Sun by one or both STEREO spacecraft has passed over one of them (or the Earth) as detected from in-situ data. These form a special class of space weather-type events that can provide information on the characteristics of the geometry, propagation and internal structure of CMEs. Important to this study are the remote imaging observations from the SECCHI Heliospheric Imagers (HIs) and, occasionally, also from the Solar Mass Ejection Imager (SMEI) in Earth orbit. HI and SMEI observations of ICMEs can provide complementary information. I will review these types of events and summarize their characteristics and what they tell us about CMEs.




Three-Dimensional Reconstructions of the Solar Wind: During Solar Minimum Conditions

M.M. Bisi, B.V. Jackson, P.P. Hick and J.M. Clover (UCSD/CASS)
M. Tokumaru, K. Fujiki (Solar-Terrestrial Environment Lab., Nagoya Univ., Japan)
R.A. Fallows and A.R. Breen (Inst. of Mathematical and Physical Sciences, Aberystwyth Univ., UK)

Interplanetary scintillation (IPS) observations provide information about a vast region of the inner heliosphere. We use Solar-Terrestrial Environment Laboratory (STELab) IPS velocity and g-level observations as well as IPS velocity observations from the European Incoherent SCATter (EISCAT) and EISCAT Svalbard Radar (ESR), with our three-dimensional (3D) reconstruction model to determine velocities and densities of the inner heliosphere. We present these observations using various forms of imaging from our time-dependent model that can measure changes with durations of less than a day and compare these with various spacecraft in situ measurements. We concentrate on the current solar-minimum period showing relatively-stable large-scale solar-wind structure during this time in relation to transients that are also sometimes present. Data primarily covers the 2007-2009 International Heliophysical Year (IHY) which includes the Whole Heliosphere Interval (CR2068).




2008 AGU Fall Meeting

San Francisco, CA, December 15 - 19, 2008



Solar Wind 3D Reconstructions of the Whole Heliospheric Interval

M.M. Bisi, B.V. Jackson, J.M. Clover, P.P. Hick, A. Buffington (UCSD/CASS)
P.K. Manoharan (Radio Astronomy Centre, NCRA, Tata Inst. of Fundamental Research, Ooty, India)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya Univ., Nagoya, Japan)

3D tomographic reconstructions of the inner heliosphere have been used for over a decade to visualise and investigate the structure of the solar wind and its various features such as transients and corotating structures. Interplanetary scintillation (IPS) observations of the solar wind have been carried out for a much longer period of time revealing information on the structure of the solar wind and the features within it. Here we present such 3D reconstructions using IPS observations from the Solar Terrestrial Environment Laboratory (STELab) and the Ootacamund (Ooty) Radio Telescope (ORT) of the Whole Heliospheric Interval (WHI) Carrington Rotation 2068. This is part of the world-wide IPS community’s International Heliosphysical Year (IHY) collaboration. We show the structure of the inner heliosphere during this time and how our global reconstructions compare with deep-space spacecraft measurements such as those taken by Wind, ACE, STEREO, and Ulysses in terms of density and velocity.




Measurements of the Gegenschein brightness from the Solar Mass Ejection Imager (SMEI)

A. Buffington, M.M. Bisi, J.M. Clover, P.P. Hick and B.V. Jackson (UCSD/CASS)

The Gegenschein is a faint diffuse component of the zodiacal light centered upon the antisolar point; this has now been viewed by the Solar Mass Ejection Imager (SMEI) for over 5 years. SMEI provides unprecedented near-full-sky photometric maps each 102-minute orbit, using data from 3 unfiltered CCD cameras. Its 0.1% photometric precision enables observation over long periods of time, of heliospheric structures having surface brightness down to several S10's (an S10 is the equivalent brightness of a 10th magnitude star spread over one square degree). When individual bright stars are removed from the maps and an empirical sidereal background subtracted, the residue is dominated by the zodiacal light. The sky coverage and duration of these measurements enables a definitive characterization. We describe the analysis method for these data, characterize the average Gegenschein brightness distribution, present empirical formulae describing its shape, and discuss its variation with time.




SMEI Remote Sensing and the 3D Reconstruction of Corotating Heliospheric Structures

B.V. Jackson, M.M. Bisi, P.P. Hick, A. Buffington and J.M. Clover (UCSD/CASS)
D.F. Webb (Inst. for Scientific Research, Boston College, MA)
M. Tokumaru (Solar-Terrestrial Lab., Nagoya Univ., Japan)
P.K. Manoharan (Radio Astronomy Ctr., Nat. Centre for Radio Astrophysics, Tata Inst. of Fundamental Research, Ooty, India)

We report observations and 3D reconstructions of corotating heliospheric structures observed by the Solar Mass Ejection Imager (SMEI). Observations of the inner heliosphere have been carried out on a routine basis by SMEI since its launch in early 2003, and these have been used to measure and map the outward flow of several-hundred CMEs. Most of these observations use short-term variations of brightness from one SMEI orbit to the next (every 102 minutes) to track outward motion. The disadvantage of these orbit\u2013to-orbit analyses is that they cannot measure features that remain stationary relative to the Sun-Earth line (or those which corotate with the Sun) and change slowly over time periods of several days. At UCSD we provide measurements of heliospheric structures relative to a long-term base and, even in these observations, there is little evidence of long-term stationary-standing density structures that corotate. By employing a kinematic model of the solar wind, we reconstruct three-dimensional (3D) solar wind structures from multiple observing lines of sight through the outward-flowing solar wind. By including interplanetary scintillation (IPS) velocity observations from STELab, Japan or from Ooty, India we can extract both the solar wind density and velocity from these analyses to compare with "ground truth" measurements from multi-point, in-situ solar wind measurements from the STEREO, SOHO, Wind, and ACE spacecraft. We define the heliospheric structures by these 3D velocity analyses, and they show that while the velocities map large regions near the ecliptic that corotate, the dense structures that front and follow these regions are far more tenuous.




Modeling the Corona-Heliosphere Interface in Anticipation of the Murchison Wide-field Array

J.C. Kasper (Smithsonian Astrophysical Observatory)
D. Oberoi and J.E. Salah (MIT-Haystack Observatory)
B.V. Jackson (UCSD/CASS)
I. Cairns (Univ. of Sydney, Australia)

The Murchison Widefield Array (MWA) is an 8,000-antenna, 80-300 MHz, imaging radio array under construction in Western Australia that features a large field of view, high sensitivity, and accurate polarization and intensity calibration. An MWA prototype has been deployed in the field and construction of the full array will begin in mid- 2009 after the performance of the prototype is evaluated. Understanding the connection between the upper corona and the inner heliosphere with novel low-frequency radio observations is a primary objective of the MWA Solar, Heliospheric, and Ionospheric (SHI) science consortium. This presentation covers progress by the SHI consortium's theory and modeling effort. We show simulations of how Faraday rotation, interplanetary scintillation, and radio burst measurements can track and constrain the transport of magnetic fields, density, and energetic electrons into the heliosphere.




Observation and Modeling of Ion Upwelling Above Aurora

D. Lummerzheim and A. Otto (Geophysical Inst., Univ. of Alaska, Fairbanks, AK, USA)
R.A. Doe (SRI, Menlo Park, CA, USA)
B.V. Jackson (UCSD/CASS, La Jolla, CA, USA)
D. Mizuno and D.F. Webb (ISR, Boston College, MA, USA)
R.L. Collins and A.S. Light (Geophysical Inst., Univ. of Alaska, Fairbanks, AK, USA)

Auroral electron precipition heats the ionospheric plasma. Especially at F-region altitudes, this leads to increased plasma pressure and a pressure gradient force that accelerates plasma away from the heated region. The resulting upward ion velocities have been observed by the incoherent scatter radar at Poker Flat (PFISR). The upward moving ions cause an increased ion density well above typical auroral ionization altitudes. N2+ ions that are lifted to altitudes above the shadowheight will resonantly scatter sunlight. This is observed by coincident overflights of the Solar Mass Ejection Imager (SMEI) on the Coriolis satellite, looking up from 840 km altitude. We will present a study that combines modeling and observations by PFISR and SMEI to illustrate and explain this process.




Whole Heliosphere Interval
Data and Modeling Assessment Workshop
Boulder, CO, August 26 - 29, 2008



The UCSD Solar Mass Ejection Imager (SMEI) and Interplanetary Scintillation (IPS) Web Database

B.V. Jackson, P.P. Hick, M.M. Bisi, A. Buffington and J.M. Clover (UCSD/CASS)

We present the current state of the UCSD Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS) database maintained and stored on UCSD/CASS Web servers. The IPS database provides real time access of Solar-Terrestrial Environment Laboratory (STELab), Japan IPS data, and provides a variety of higher-level data products derived from these observations to help in Space Weather Forecasting. The up-to-date UCSD SMEI database includes individual SMEI CCD data frames from each of the three SMEI cameras since launch and first light in February 2003, as well as full-sky maps in a sidereal reference frame that preserve the original resolution and photometric precision. Higher-level products from the low-resolution 3D analysis of this database are also maintained from launch up to the present. The IPS data and the modeling capability demonstrated as real-time data access in these analyses are available at the Community Coordinated Modeling Center (CCMC), as are the IPS data from STELab from the year 2000 up to the present. See: http://ips.ucsd.edu/, http://smei.ucsd.edu

PDF Poster



SHINE-GEM 2008 Workshop
Zermatt, Utah, June 23 - 27, 2008



3D Reconstructions of the Inner Heliosphere
M.M. Bisi, Bernard V. Jackson, P. Paul Hick, Andrew Buffington and John M. Clover (UCSD/CASS)

Interplanetary scintillation (IPS) observations provide a view of the solar wind at all heliographic latitudes from coronagraph fields of view to solar elongation angles >90 degrees from the Sun. The Solar Mass Ejection Imager (SMEI) provides white-light brightness coverage with a better spatial resolution than IPS from about 20 degrees elongation to the anti-solar direction at 180 degrees elongation. These observations can be used to study the evolution of the solar wind, corotating structure, and solar transients as they propagate out into interplanetary space. We use a three-dimensional (3D) reconstruction technique that obtains perspective views from solar corotating plasma and outward-flowing solar wind as observed from the Earth. This is achieved by iteratively fitting a kinematic solar wind model to IPS radio and SMEI white-light observations. This 3D modeling technique permits reconstruction of the density and velocity structures of coronal mass ejections (CMEs) and other interplanetary transients at a relatively coarse resolution, as well as the background solar wind. The resolutions are better both spatially and temporally when used with SMEI white-light observations to perform density reconstructions. Here we present 3D reconstructions of events which include the 28-30 May 2003, 13-15 May 2005, and December 2006 CME periods as observed by SOHO|LASCO using both (when data are available) multi-system IPS and SMEI observations.




The UCSD Solar Mass Ejection Imager (SMEI) and Interplanetary Scintillation (IPS) Web Database

B.V. Jackson, P.P. Hick, M.M. Bisi, A. Buffington and J.M. Clover (UCSD/CASS)

We present the current state of the UCSD Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS) database maintained and stored on UCSD/CASS Web servers. The IPS database provides real time access of Solar-Terrestrial Environment Laboratory (STELab), Japan IPS data, and provides a variety of higher-level data products derived from these observations to help in Space Weather Forecasting. The up-to-date UCSD SMEI database includes individual SMEI CCD data frames from each of the three SMEI cameras since launch and first light in February 2003, as well as full-sky maps in a sidereal reference frame that preserve the original resolution and photometric precision. Higher-level products from this database are maintained for select intervals from launch up to the present. The IPS data and the modeling capability demonstrated as real-time data access in these analyses are available at the Community Coordinated Modeling Center (CCMC), as are the IPS data from STELab from the year 2000 up to the present. UCSD/CASS websites: http://ips.ucsd.edu/ and http://smei.ucsd.edu/




AGU/SPD Meeting of the Americas, 2008 Joint Assembly
Fort Lauderdale, FL, May 27 - 30, 2008



SMEI Observations of the Heliosphere During WHI

B.V. Jackson, M.M. Bisi, P.P. Hick, A. Buffington and J.M. Clover (UCSD/CASS)
D.F. Webb (ISR, Boston College, Chestnut Hill, MA, Chestnut Hill, MA)

Solar Mass Ejection Imager (SMEI) observations of the inner heliosphere have been carried out on a routine basis since early 2003. By employing a kinematic model of the solar wind, we reconstruct three-dimensional (3D) solar wind structures from multiple observing lines of sight through the outward-flowing solar wind. These models allow us to extract solar wind density and to compare these to "ground truth" measurements from multi-point in-situ solar wind measurements from the STEREO, SOHO, ACE, and the Wind spacecraft. This aids in improving the 3D reconstruction technique by comparing these reconstructions at multiple points in the inner heliosphere. Because our observations reveal the global nature of heliospheric structures, this also leads to a better understanding of the structure and dynamics of the interplanetary environment around each spacecraft, and how these structures are connected back to the Sun. During the Whole Heliosphere Interval (WHI) SMEI will provide views and 3D reconstructions of the global heliosphere that can be compared with ground-based and spacecraft observations.




Whole Heliosphere Interval: Overview of Heliospheric Observations

A.B. Galvin (Univ. of New Hampshire, Space Science Ctr., Morse Hall, Durham, NH)
S. Gibson (HAO/NCAR, Boulder, CO)
with the Heliosphere Team (incl. M.M. Bisi)

The Whole Heliosphere Interval (http://ihy2007.org/WHI/) is an international observing and coordinated modeling effort to characterize the interconnections of the 3-dimensional sun-heliosphere-planetary system originating from Carrington Rotation 2068. WHI takes place one solar cycle after the "Whole Sun Month" campaign of 1996. Both WSM and WHI covered the sun and heliosphere near solar minimum conditions, providing a basis for comparison from one solar cycle to the next. The primary goals for WHI include the characterization and modeling in 3D of the solar minimum heliosphere, and to trace the affects of solar structure and activity via the solar wind to Earth, other planetary systems, and the outer heliosphere. Team participants address solar, heliospheric, geospace, planetary systems, space weather, and sun-climate observations and models. In this talk, we provide a "first results" summary of the heliospheric observations portion of WHI. At this writing, the heliospheric observations are expected to include modeling as well as measurements from L1 (ACE, SOHO, Wind), other solar longitudes near 1 AU (STEREO A, STEREO B), remote sensing from Earth or near-Earth (Ooty Radio Observatory, SMEI, EISCAT), out-of-the ecliptic (Ulysses), and from the outer heliosphere (Voyager, IBEX). For Voyager and IBEX, the observing interval extends until the affects originating from CR 2068 reach the outer heliosphere, several months later.




Space Weather Week 2007
Boulder, Colorado, April 29 - May 2, 2008



The UCSD Solar Mass Ejection Imager (SMEI) Web Database

B.V. Jackson, P.P. Hick, A. Buffington, M.M. Bisi and J.M. Clover (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) has been operating nearly continuously since "first light" on the Coriolis spacecraft in early February, 2003. We present the current state of the SMEI database maintained and stored on a UCSD/CASS Web server. The up-to-date UCSD database includes individual SMEI CCD data frames from each of the three SMEI cameras since launch as well as single-orbit full-sky maps in a sidereal reference frame that preserve the original resolution and photometric precision. A Web interface to this latter data set describes the database and allows display of these maps in sun-centered ecliptic coordinates, either directly or as running differences. Further processing of the SMEI data for select periods has allowed the removal of zodiacal cloud brightness, auroral signals, bright stars, and the sidereal background. These data are also available on the Web as time series for select locations on these sky maps and sky maps with a long-term base brightness removed. An interface to these SMEI sky maps allow side-by side comparisons of direct and difference sky maps from this data set with those processed by the UCSD low-resolution 3D reconstruction technique.

PDF Poster



Chapman Conference on the Solar Wind Interaction with Mar
San Diego, CA, January 22 - 25, 2008



Tomographic Reconstructions of the Solar Wind from Heliospheric Remote Sensing Observations: Density and Velocity Predictions at Mars
P.P. Hick, B.V. Jackson, M.M. Bisi, A. Buffington and J. Clover (UCSD/CASS)

Remote sensing observations of the solar wind over a large range of elongations (angular distances from the Sun) provide a data base for modeling the solar wind in the inner heliosphere, out to and beyond the orbit of Mars. We use interplanetary scintillation (IPS) data from meter-wavelength radio systems (from STELab, Univ. of Nagoya, Japan), and Thomson scattering brightness data (from the Solar Mass Ejection Imager, SMEI) in tomographic reconstructions of the density and radial outflow velocity of the solar wind, both in corotating structures and in transient features such as coronal mass ejections (CMEs). We describe our 3D reconstruction technique that relies on the changing perspective view of solar wind structures from solar rotation and outward flow as observed from Earth. The technique allows reconstruction of solar wind structure of CMEs at a resolution determined by the angular and temporal resolution of the remote sensing data. We obtain estimates of solar wind parameters at specific heliospheric locations (e.g., Earth, Mercury and deep space spacecraft such as Ulysses, and Stereo A and B) as a time series extracted from the 3D density and velocity solutions. Here we discuss the density and velocity obtained at Mars in comparison with the dynamic pressure at Mars as modeled from magnetometer data taken by the Mars Global Surveyor (Crider et al., J. Geophys. Res. 108(A12), 1461, 2003). We emphase variations in dynamic pressure that are related with CMEs observed in the remote sensing observations.

PDF Poster



2007 AGU Fall Meeting
San Francisco, CA, December 10 - 14, 2007



Analysis and Interpretation of Comet Measurements from SMEI

A. Buffington, M.M. Bisi, J.M. Clover, P.P. Hick, B.V. Jackson (UCSD/CASS)

he Solar Mass Ejection Imager (SMEI) has observed several comets and traced their plasma tails as far as 108 km from their nucleus. A time sequence of SMEI orbital sky maps displays considerable tail motion and disruption for several of these comets. Tracking these motions versus time, when combined with ephemeris information about their distance from the Earth allows a determination of solar wind speeds and their variation with the location of the comet. In the case of comets C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR), which passed within about 0.3 AU of Earth in April and May of 2004, the SMEI observations show that speeds during disruptions are typically 50 to 100 km s-1 less than speeds before and after. Time durations of the disturbances vary between 3 and 8 hours, and correspond to distances traversed by the comets of ~106 km (0.007 AU). We compare these observations with interplanetary scintillation (IPS) three-dimensional tomographic reconstructions and find no evidence that the comet-tail features are due to large-scale density or velocity structures. We also compare these with near-by spacecraft measurements such as the Advanced Composition Explorer (ACE), and find a similar result. This suggests that the comet-tail disruptions are caused by small-scale changes in the solar wind acting over distances that are short compared with 1 AU.

PDF Poster


IPS Observations of the Inner-Heliosphere and their Comparison with Multi-Point In-situ Measurements

M.M. Bisi and B.V. Jackson (UCSD/CASS)
A.R. Breen and R.A. Fallows (Univ. of Wales, Aberystwyth)
J. Feynman (NASA/JPL)
J.M. Clover, P.P. Hick and A. Buffington (UCSD/CASS)

Interplanetary scintillation (IPS) observations of the inner-heliosphere have been carried out on a routine basis for many years using metre-wavelength radio telescope arrays. By employing a kinematic model of the solar wind, we reconstruct the three-dimensional (3D) structure of the inner-heliosphere from multiple observing lines of sight. From these reconstructions we extract solar wind parameters such as velocity and density, and compare these to “ground truth” measurements from multi-point in situ solar wind measurements from ACE, Ulysses, STEREO, and the Wind spacecraft, particularly during the International Heliophysical Year (IHY). These multi-point comparisons help us improve our 3D reconstruction technique. Because our observations show heliospheric structures globally, this leads to a better understanding of the structure and dynamics of the interplanetary environment around these spacecraft.

PDF Poster


Inner-Heliosphere SMEI Observations and their Comparison with Multi-Point In-situ Measurements

B.V. Jackson, M.M. Bisi, P.Paul Hick, A. Buffington and J.M. Clover (UCSD/CASS)
J. Feynman (NASA/JPL)

Solar Mass Ejection Imager (SMEI) observations of the inner heliosphere have been carried out on a routine basis since shortly after its launch on January 6, 2003. By employing a kinematic model of the solar wind, we reconstruct three-dimensional (3D) solar wind structures from multiple observing lines of sight through the outward-flowing solar wind. This model allows us to extract solar wind densities from the SMEI white-light observations and to compare these to multi-point in situ “ground truth” solar wind measurements from instruments aboard the Ulysses, STEREO, ACE, and Wind spacecraft. This facilitates improvements to our 3D reconstruction technique by comparing these reconstructions at multiple points in the inner-heliosphere. Our observations show heliospheric structures globally, and because of this, our reconstructions provide us with a better understanding of the structure and dynamics of the interplanetary environment around each spacecraft, and how these structures are connected back to the Sun.




A 3D View of Coronal Mass Ejections in Interplanetary Space

A.R. Breen and G.D. Dorrian (Univ. of Wales, Aberystwyth, UK)
M.M. Bisi (UCSD/CASS, La Jolla, CA, USA)
C.J. Davis (Rutherford-Appleton Lab., UK)
R.A. Fallows (University of Wales, Aberystwyth, UK)
H. Morgan (Univ. of Hawaii, HI, USA)
R.A. Harrison (Rutherford-Appleton Lab., UK)

Ground-based measurements of interplanetary scintillation (IPS) have been used to study the solar wind for many years, but interpretation of the results has always been rendered more difficult by uncertainty about the electron density distribution along the extended line-of-sight from radio source to antenna. This has been particularly marked in the case of Earth-directed coronal mass ejections (CMEs). The launch of the STEREO spacecraft, with its Heliospheric Imager (HI) instruments, provides us with the first detailed view of structures in the Sun-Earth line, revealing the motion of large-scale density structures, and greatly reducing the uncertainties in interpreting IPS observations of the speeds of small-scale irregularities embedded within the larger structures. In this poster we present results from a co-ordinated programme of measurements which brings together STEREO HI and two different IPS experiments. We consider two events, one from 2005 in which we use a combination of long-baseline IPS measurements from EISCAT and MERLIN, tomographically-reconstructed 3D density distributions from STELab IPS observations, and SOHO EIT and LASCO images to track the development of an Earth-directed CME. We discuss the remaining uncertainties in this approach and the ways in which STEREO HI images would have assisted with the analysis. In the second event we combine STEREO HI observations of structures in the solar wind with IPS measurements of solar wind speed from EISCAT and MERLIN and tomographic reconstructions of 3D structure. We discuss the results and present suggestions for future co-ordinated campaigns.

PDF Poster



The 4th CCMC Community Workshop
Arecibo Observatory, Puerto Rico, November 5-8, 2007



UCSD Heliospheric Tomography model at CCMC: current status and future plans

P.P. Hick, B.V. Jackson, M.M. Bisi, A. Buffington and J. Clover (UCSD/CASS)

(NOT AVAILABLE)




Living With A Star Science Workshop
Boulder, CO, September 10 - 13, 2007



STEREO-Era Solar Mass Ejection Imager (SMEI) Observations

B. V. Jackson, A. Buffington, P. P. Hick, M.M. Bisi, E.A. Jensen (UCSD/CASS)

White-light Thomson scattering observations by the Solar Mass Ejection Imager (SMEI) have recorded the inner heliospheric response to corotating structures and CMEs. Some of the CMEs are also observed by LASCO and, most recently, the STEREO spacecraft. Here we detail several events in SMEI observations that have also been observed by the LASCO coronagraphs and STEREO spacecraft. We show how SMEI is able to measure CME events starting from their first observation at as close as 20 deg. from the solar disk until they fade away in the SMEI 180 deg. field of view. Our 3D reconstruction technique provides perspective views as observed from Earth, from outward-flowing solar wind. This is accomplished by iteratively fitting the parameters of a kinematic solar wind density model to the SMEI white-light observations and, where possible, including interplanetary scintillation (IPS) velocity data. Comparisons with LASCO and STEREO images for individual events or portions of them allow a detailed view of changes in their structure shape and mass as they propagate outward.

PDF Poster



2007 SPIE Optics & Photonics
San Diego, CA, August 26 - 30, 2007



A Procedure for Fitting Point Sources in SMEI White-Light Full-Sky Maps
P.P. Hick, A. Buffington and B.V. Jackson (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) instrument consists of three CCD cameras with individual fields of view of 60°×3° that combined sweep a 160° arc of sky. SMEI sweeps the entire sky in one spacecraft orbit of 102 minutes. Individual 4-s exposures from each orbit are assembled into full-sky maps. The primary objective in the SMEI data reduction is to isolate the Thomson-scattering signal from free electrons in the solar wind across the sky. One of the steps needed to achieve the required photometric precision is the individual fitting and removal of stars brighter than 6th magnitude from the full-sky maps. The point-spread function of the SMEI optics has several unusual properties. It has a full width of about one degree, is asymmetric, and varies in width depending on where in the FOV the image is formed. Moreover, the orientation of the PSF on the sidereal sky rotates over 360° over the course of a year. We describe the procedure used to fit and subtract individual stars from the SMEI full-sky maps. A by-product of this procedure are time series with the orbital time resolution for stars brighter than 6th magnitude. These results are used by Buffington et al. (2007, this meeting) to calibrate the SMEI instrument against the LASCO C3 coronagraph.

PDF Poster


Analysis of the Comparative Responses of SMEI and LASCO
A. Buffington (UCSD/CASS)
J.S. Morrill (Naval Research Lab.)
P.P. Hick (UCSD/CASS)
R.A. Howard (Naval Research Lab.)
B.V. Jackson (UCSD/CASS)
D.F. Webb (ISR, Boston College, Inst. for Scientific Research)

Surface-brightness responses of the C3 coronagraph in LASCO and of the Solar Mass Ejection Imager (SMEI) are compared, using measurements of a selection of bright stars that have been observed in both instruments. Seventeen stars are selected to be brighter than 4.5 magnitudes, not be known variables, and not have a neighboring bright star. Comparing observations of these determines a scaling relationship between surface-brightness measurements from one instrument to those from the other. We discuss units of surface brightness for the two instruments, and estimate a residual uncertainty for the present scaling relationship.

PDF Poster


SMEI Observations in the STEREO Era
B.V. Jackson, A. Buffington, P.P. Hick, M.M. Bisi and E.A. Jensen (UCSD/CASS)

White-light Thomson scattering observations from the Solar Mass Ejection Imager (SMEI) have recorded the inner heliospheric response to many CMEs. Some of these are also observed from the LASCO and, most recently, the STEREO spacecraft. Here we detail several CME events in SMEI observations that have also been observed by the LASCO and STEREO spacecrafts. We show how SMEI is able to measure CME events from their first observations as close as 20? from the solar disk until they fade away in the SMEI 180? field of view. We employ a 3D reconstruction technique that provides perspective views as observed from Earth, from outward-flowing solar wind. This is accomplished by iteratively fitting the parameters of a kinematic solar wind density model to the SMEI white-light observations and, where possible, including interplanetary scintillation (IPS) velocity data. This 3D modeling technique enables separating the true heliospheric response in SMEI from background noise, and reconstructing the 3D heliospheric structure as a function of time. These reconstructions allow both separation of CME structure from other nearby heliospheric features and a determination of CME mass. Comparisons with LASCO and STEREO images for individual CMEs or portions of them allow a detailed view of changes to the CME shape and mass as they propagate outward.




Combined STELab, EISCAT, ESR, and MERLIN IPS Observations of the Solar Wind
M.M. Bisi and B.V. Jackson (UCSD/CASS)
R.A. Fallows and A.R. Breen
(Inst. of Mathematical and Physical Sciences, Univ. of Wales, Aberystwyth

P.P. Hick (UCSD/CASS)
G. Wannberg (EISCAT Scientific Association, Kiruna)
P. Thomasson and C. Jordan (Jodrell Bank Observatory, University of Manchester)
G.D. Dorrian (Inst. of Mathematical and Physical Sciences, Univ. of Wales, Aberystwyth

The technique of interplanetary scintillation (IPS) can be used to probe the interplanetary space between the Sun and the Earth. We combine the large spatial-scale tomographic techniques previously applied to data from the STELab array in Japan, with the finer-scale capabilities of the longer baselines between the systems of MERLIN in the UK, and EISCAT and the ESR in northern Scandinavia. We present results of detailed solar wind velocity measurements and those of solar wind flow-directions, constrained by the largescale tomography through the use of a kinematic model.




SCOSTEP International CAWSES Symposium
Kyoto, Japan, October 23-27, 2007



3D reconstructions using interplanetary scintillation (IPS) and the Solar Mass Ejection Imager (SMEI) data
M.M. Bisi and B.V. Jackson (UCSD/CASS)
P.K. Manoharan (Radio Astron. Ctr, TATA Inst. of Fundamental Res., Ooty, India)
R.A. Fallows (Inst. of Mathematical and Physical Sciences, Univ. Wales, Aberystwyth, UK)
M. Kojima and M. Tokumaru (STELab, Nagoya Univ., Nagoya, Japan)
A.R. Breen (Inst. of Mathematical and Physical Sciences, Univ. Wales, Aberystwyth, UK)
P. Paul Hick (UCSD/CASS)
G.D. Dorrian (Inst. of Mathematical and Physical Sciences, Univ. Wales, Aberystwyth, UK)
J.M. Clover and A. Buffington (UCSD/CASS)

Combined interplanetary scintillation (IPS) and Solar Mass Ejection Imager (SMEI) remote-sensing observations provide a view of the solar wind at all heliographic latitudes and solar elongations; from ~180 degrees anti-solar, down to coronagraph fields-of-view. They can be used to study the evolution of the solar wind, solar transients (such as mass ejections), and corotating structures out into interplanetary space, both in scintillation-level and in velocity for IPS, and Thomson-scattered white-light brightness for SMEI. Here, we show comparisons of events reconstructed using differeing IPS systems and SMEI (such as those in early November 2004 observed by STELab, ORT, and SMEI) by using a 3D reconstruction technique that obtains perspective views from solar corotating plasma and outward-flowing solar wind as observed from the Earth by iterative fitting of a kinematic solar wind model to the different data sets. We also make comparisons of the structures seen in the 3D reconstructions with in-situ measurements such as those from ACE and Ulysses dependent upon the location(s) of spacecraft.




A new view of space weather - combining IPS and STEREO HI observations of the solar wind with studies of ionospheric consequences
A. Breen (Univ. Wales, Aberystwyth, UK)
C. Davis (Rutherford-Appleton Lab., Chilton, UK)
G. Dorrian and R. Fallows (Univ. Wales, Aberystwyth, UK)
H. Morgan (Univ. Hawaii, Honolulu, HI, USA)
M. Bisi (Univ. California San Diego, La Jolla, CA, USA)
H. Middleton and E. Whittick (Univ. Wales, Aberystwyth, UK)
D. Bewsher, R. Harrison, S. Crothers and J. Davis (Rutherford-Appleton Lab., Chilton, UK)
C. Eyles (Univ. Birmingham, Birmingham, UK)
P. Thomasson (Jodrrell Bank Obs., Univ. Manchester, UK)
G. Wannberg (EISCAT Scient. Ass., Kiruna, Sweden)

The availability of data from the Heliospheric Imager instruments on the STEREO spacecraft provide the first detailed view of the Sun-Earth line. Such observations reveal structure and movement of large-scale features, and are perfectly complemented by ground-based radio scintillation (IPS) measurements of speed and direction of small-scale structure. In this paper we present results from a coordinated programme of measurements bringing together STEREO HI, IPS and ionospheric tomography. We combine STEREO HI observations of structures in solar wind with IPS measurements of solar wind speed from EISCAT and MERLIN, while ionospheric tomography data and modelling are used to study the reponse of the Earth's ionosphere to solar wind variations. We discuss the observations and our methodology, before going on to draw conclusions for the events observed and discuss the lessons learned for future observing campaigns.




CME 3D reconstructions using Solar Mass Ejection Imager and interplanetary scintillation data and extrapolation to Ulysses
B.V. Jackson, P.P. Hick, A. Buffington, M.M. Bisi and E.A. Jensen (UCSD/CASS)
M. Kojima and M. Tokumaru (STELab, Nagoya Univ., Nagoya, Japan)

We have available a UCSD 3D reconstruction technique that obtains perspective views from solar corotating plasma and outward-flowing solar wind as observed from Earth by iteratively fitting a kinematic solar wind model to either Solar Mass Ejection Imager (SMEI) or interplanetary scintillation (IPS) observations or a combination of these two data sets. This 3D modeling techniques permits reconstruction of the density and velocity of corotating structures and CMEs. In this ongoing study, we compare SMEI and STELab observations (both direct and using the 3D reconstructions) from data obtained this year while the Ulysses spacecraft is near the Sun and the STEREO spacecraft are near Earth, and extrapolate these observations to the Ulysses spacecraft. Our observations provide remote-sensing measurements and global context for heliospheric structures which here-to-fore have been interpolated between and extended from multi-spacecraft observations. We do this as well to determine noise from signal in the data sets, to discover the differences between the SMEI and IPS remote-sensing data sets, and to certify the UCSD 3D reconstruction technique by comparison with solar wind in-situ observations from spacecraft distant from Earth.




SHINE 2007 Workshop
Whistler, Canada, July 30 - August 3, 2007



Vital Statistics From an Initial Combination of 3D Tomographic Data and ACE During CME Crossings
E.A. Jensen , B.V. Jackson , M.M. Bisi , A. Buffington and J. Clover (UCSD/CASS)
T.L. Mulligan (Aerospace Corp)

Thomson-scattering observations of the solar corona out to 3 AU from SMEI are analyzed using 3D tomography to give the distribution of electron density (n) in the heliosphere with a time resolution of 6 hours. Interplanetary scintillation (IPS) observations are a nonlinear function of velocity on scales of roughly 200 km. Using the technique from Jackson and Hick (2005), the IPS observations from STELab are analyzed with 3D tomography to obtain the radial velocity (v) throughout the heliosphere with a time resolution of 12 hours. In orbit at the Earth's L1 point, ACE measures the local plasma properties and magnetic field with which the results from these tomographic reconstructions can be compared. The electron density is inferred from ACE observations assuming charge neutrality. Studying the time periods of CME Earth-crossings for a few select events, we will show our results of the comparison between the Thomson-scattering (n), IPS (v), and ACE (n and v) data. We will also show a spatial comparison between the size of the local magnetic structure of ICMEs observed by ACE (including the flux rope orientation in the case of magnetic clouds) and the regional extent and volume of the enhanced electron density and velocity regions from the tomographic reconstructions. These initial "vital" statistics will allow us to begin investigating the structure of the heliosphere as a CME convects outward in the solar wind.


PDF Poster


Solar Mass Ejection Imager (SMEI) Analysis of the 20 January 2005 CME
B.V. Jackson, P.P. Hick, A. Buffington, M.M. Bisi and E.A. Jensen (UCSD/CASS)

Solar Mass Ejection Imager (SMEI) brightness measurements are analyzed to determine the 3D volumetric density of the 20 January 2005 CME. We use this system to measure the distribution of structure and provide a 3D mass of the ejecta associated with the large CMEs viewed in SMEI observations. The primary mass of the 20 January 2005 CME moves to the northwest of the Sun following the event observed earlier in LASCO coronagraph observations. There are two other very large coronal responses to the coronal energy input beginning around 6:30 UT near the time of CME onset. One of these is the large and extremely prompt Solar Energetic Particle (SEP) proton event observed at Earth beginning about 6:50 UT. Another response is an outward-propagating fast shock that arrives at Earth 34 hours following the event onset. A response that may be attributed to this shock is observed slightly more than 5 days following this at the Ulysses spacecraft situated 5.3 AU from the Sun, 17 degrees south of the ecliptic, and 27 degrees from the Sun-Earth line to the west. SMEI observes the white-light response of this shock at Earth in the interplanetary medium around the spacecraft, and limits the shock extent in 3D.


PDF Poster



Asia Oceania Geosciences Society, 4th Annual Assembly
Bangkok, India, 30 July-4 August, 2007



CME Reconstructions Using Interplanetary Scintillation Data
M.M. Bisi, B.V. Jackson, P.P. Hick, and A. Buffington (UCSD/CASS)

Interplanetary scintillation (IPS) observations provide a view of the solar wind at all heliographic latitudes from around 1 A.U. down to coronagraph fields of view. It can be used to study the evolution of the solar wind and solar transients out into interplanetary space and also the inner heliospheric response to corotating solar structures and coronal mass ejections (CMEs), both in scintillation level and in velocity. With colleagues at STELab, Nagoya University Japan, we have developed near-real-time access of STELab IPS data for use in space-weather forecasting. We use a three-dimensional reconstruction technique that obtains perspective views from solar corotating plasma and outward-flowing solar wind as observed from the Earth by iteratively fitting a kinematic solar wind model to IPS observations. This 3D modeling technique permits reconstructions of the density and velocity structures of CMEs and other interplanetary transients at a relatively coarse resolution. These reconstructions have a solar-rotation cadence with 10° latitudinal and longitudinal heliographic resolution for the corotational model, and a one-day cadence and 20° latitudinal and longitudinal heliographic resolution for the time-dependent model predicated by the numbers of lines of sight available for the reconstructions. When SMEI Thomson-scattering analyses are used, the numbers of lines of sight increase greatly so that density reconstructions can be far-better resolved. Higher resolutions are possible too, when these analyses are used with Ooty IPS data that are also demonstrated in these analyses.




EISCAT workshop 2007
Northern Scandinavia, August 2007



Extremely long-baseline interplanetary scintillation measurements - a tool for probing solar wind structure
A. Breen, R. Fallows and G. Dorrian (University of Wales, Aberystwyth, UK)
M.M. Bisi (UCSD/CASS)

Two-site measurements of interplanetary scintillation have been used to study solar wind velocities for over 30 years, but recent developments using EISCAT and MERLIN have led to new insights into the large-scale structure of the inner heliosphere. In this presentation we discuss these observations and present highlights from recent results. These include evidence of a distinct change in fast solar wind speed between the polar crown outflow and the flow from the equatorwards extension of a polar coronal hole, observations of super-radial expansion of the fast wind at heliocentric distances of 25-80 solar radii and evidence for flow rotation in stream interaction regions and in the solar wind perturbed by the passage of a iCME. We compare our results with those obtained from tomographic reconstructions based on lower-frequency IPS observations from the STELab telescope network in Japan and show that the combination of the two IPS approaches provides a powerful tool for studying solar wind structure.




Equatorwards Expansion of the Fast Solar Wind
G. Dorrian, A. Breen and R. Fallows (University of Wales, Aberystwyth, UK)
M.M. Bisi (UCSD/CASS)
P. Thomasson (Jodrell Bank Observatory, UK)
G. Wannberg (EISCAT Scientific Association, Kiruna, Sweden)

We present results from Interplanetary Scintillation (IPS)observations made jointly with the EISCAT system in Scandinavia and the MERLIN system in the UK. These results provide evidence of a small but measureable equatorwards velocity component in the fast solar wind typically of the order of 1° - 2° off radial direction. Possible reasons for this expansion and further investigations are discussed.




210th AAS Meeting
Honolulu, HI, May 27-31, 2007



CME 3D Reconstructions Using Solar Mass Ejection Imager and Interplanetary Scintillation Data
B.V. Jackson, M.M. Bisi, P.P. Hick, A. Buffington (UCSD/CASS)

Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS) observations provide a view of the solar wind at all solar elongations; from 180 degrees anti-solar to as close to the Sun as coronagraph fields of view. They can be used to study the evolution of the solar wind and solar transients out into interplanetary space. In addition, the inner heliospheric response to corotating solar structures and coronal mass ejections (CMEs) can be measured, both in scintillation level and in velocity when using IPS, and through Thomson Scattering when using SMEI. We use a 3D reconstruction technique that obtains perspective views from solar corotating plasma and outward-flowing solar wind as observed from Earth, by iteratively fitting a kinematic solar wind model to both SMEI and IPS observations. This 3D modeling technique permits reconstructions of the density and velocity structures of CMEs and other interplanetary transients. These reconstructions have a temporal cadence and heliographic latitudinal and longitudinal resolution predicated by the amount of data used for time-dependent reconstructions, and can use data from a variety of IPS instruments distributed around the Earth. We highlight the 3D analyses of these different data sets using a series of CME events observed beginning on the Sun 4-7 November 2004. We also apply this technique to determine solar wind pressure ("cram" pressure) at Mars. Results are compared with ram pressure observations derived from Mars Global Surveyor magnetometer data for the years 1999 through 2004, and include a reconstruction of a "back-side" event as seen by SOHO/LASCO.


PDF Poster



Space Weather Week 2007
Boulder, Colorado, April 24 - 27, 2007



3-D Numerical Simulations of Heliospheric Disturbances Driven by SMEI/IPS Observation
D. Odstrcil (CU/CIRES, NOAA/SEC)
B.V. Jackson and P. Hick (UCSD/CASS)

Solar Mass Ejections Imager (SMEI) observations are routinely combined with interplanetary scintillation (IPS) observations from Nagoya, Japan, to reconstruct solar wind density and velocity structure in the inner heliosphere. We have developed procedures to utilize these data sets to derive the time-dependent boundary conditions, which are then used to drive our numerical heliospheric code ENLIL. We will present the results achieved from numerical simulations of selected complex and violent heliospheric events. Simulated density and velocity structures are compared with kinematic reconstructions and with in-situ observations.




NAM/MIST/UKSP 2007
Preston, England, UK, April, 2007



Equatorwards expansion of the Fast Solar Wind
G. Dorrian, A. Breen and R. Fallows (Inst. Mathematical and Physical Sciences, University of Wales, Aberystwyth)
M.M. Bisi (UCSD/CASS)
G. Wannberg (EISCAT Scientific Association, Kiruna, Sweden)

We present results from Interplanetary Scintillation (IPS) observations made jointly with the EISCAT system in Scandinavia and the MERLIN system in the UK. Prior results have provided evidence of a small but measureable equatorwards velocity component in the fast solar wind typically of the order of 1° - 2° off radial direction. In this paper we present the first results of applying a weak scattering model to these observations, confirming an equatorwards expansion. Possible reasons for this expansion are discussed.




LWS Geostorm CDAW and Conference,
Living With a Star - Coordinated Data Analysis Workshop
Florida Tech - Melbourne, FL, March 5-9, 2007



CME Reconstructions Using Interplanetary Scintillation Data
M.M. Bisi, B.V. Jackson, P.P. Hick, and A. Buffington (UCSD/CASS)

Interplanetary scintillation (IPS) observations provide a view of the solar wind at all heliographic latitudes from around 1 A.U. down to coronagraph fields of view. It can be used to study the evolution of the solar wind and solar transients out into interplanetary space and also the inner heliospheric response to corotating solar structures and coronal mass ejections (CMEs), both in scintillation level and in velocity. With colleagues at STELab, Nagoya University Japan, we have developed near-real-time access of STELab IPS data for use in space-weather forecasting. We use a three-dimensional reconstruction technique that obtains perspective views from solar corotating plasma and outward-flowing solar wind as observed from Earth by iteratively fitting a kinematic solar wind model to IPS observations. This 3D modeling technique permits reconstructions of the density and velocity structures of CMEs and other interplanetary transients at a relatively coarse resolution. These reconstructions have a solar-rotation cadence with 10° latitudinal and longitudinal heliographic resolution for the corotational model, and a one-day cadence and 20? latitudinal and longitudinal heliographic resolution for the time-dependent model. This technique is used to determine solar wind pressure ("ram" pressure) at Mars. Results are compared with ram pressure observations derived from Mars Global Surveyor magnetometer data for the years 1999 through 2004 and include a reconstruction of a "back-side" event as seen by SOHO|LASCO.




2006 Fall AGU Meeting
San Francisco, CA, December 11 - 15, 2006



An Empirical Description of Zodiacal Light as Measured by SMEI
A. Buffington, B.V. Jackson, P.P. Hick (UCSD/CASS)
S.D. Price (Air Force Research Lab., Space Vehicles Directorate, Hanscom AFB)

The SMEI visible-light cameras provide a photometric skymap for each 102-minute orbit with the objective to observe transient Coronal Mass Ejections (CMEs). Zodiacal light is a significant contributor to these maps and must be removed in the data-analysis in order to detect and characterize the much fainter CMEs. We have analyzed over three years of the SMEI calibration data that were taken at the highest spatial resolution to derive the yearly averaged global distribution of zodiacal light between solar elongations of 20° and 180°. Residuals on the individual sky maps from this global average provide information on the detailed geometry of the clouds. We present preliminary results of the analysis, including a characterization of the Gegenschein, possible dust bands, and annual variations.


Powerpoint Presentation


The 20 January 2005 CME Solar Mass Ejection Imager (SMEI) Analyses
B.V. Jackson, P.P. Hick, A. Buffington (UCSD/CASS)

Solar Mass Ejection Imager (SMEI) brightness measurements are analyzed to determine 3D volumetric densities for several CMEs including that of the 20 January 2005 CME. Here we present analyses of these 3D heliospheric volumetric solar wind density analyses. We use this system to measure the distribution of structure and provide a 3D mass of the ejecta associated with the large CMEs viewed in SMEI observations. In the case of the 20 January 2005 CME, the primary mass moves to the northwest of the Sun following the event observed earlier in LASCO coronagraph observations. There are two other very large coronal responses to the coronal energy input beginning around 6:30 UT near the time of CME onset. One of these is the large and extremely prompt Solar Energetic Particle (SEP) proton event observed at Earth beginning about 6:50 UT. Another response is an outward-propagating fast shock that arrives at Earth 34 hours following the event onset. A response that may be attributed to this shock is observed slightly more than 5 days following this at the Ulysses spacecraft situated 5.3 AU from the Sun, 17° south of the ecliptic, and 27° from the Sun-Earth line to the west. SMEI observes the white-light response of this shock at Earth in the interplanetary medium around the spacecraft, and limits the shock extent in 3D.


PDF Poster


The evolution of comets in the heliosphere as observed by SMEI
T. Kuchar (Boston College, Institute for Scientific Research, Chestnut Hill, MA)
A. Buffington (UCSD/CASS, La Jolla, CA)
T. Howard (Montana State University, Physics Dept., Bozeman, MT)
C.N. Arge (Air Force Research Lab, VSBXS, Hanscom AFB, MA)
D. Webb (Boston College, Inst. for Scientific Research, Chestnut Hill, MA)
B.V. Jackson and P.P. Hick (UCSD/CASS, La Jolla, CA)

Comet observations have been used as in situ probes of the heliospheric environment since they were used to confirm the existence of the solar wind. Changes in a comet tail's appearance are attributed to changes in the solar wind flow. Large scale tail disruptions are usually associated with boundary crossings of the current sheet or, more rarely, impacts from coronal mass ejections. The Solar Mass Ejection Imager (SMEI) observed three bright comets during April-May 2004: Bradfield (C/2004 F4), LINEAR (C/2002 T7), and NEAT (C/2001 Q4). We had previously reported several comet tail disconnection events (DEs) for both NEAT and LINEAR. Investigation of the entire period further reveals that these two comets showed continual changes in their plasma tails. These changes are characterized by a "smokestack-like" billowing effect punctuated by the disconnections. Bradfield however was remarkably quiescent during this entire period. We present these extended comet observations and offer an analysis and cause of the similarities and disparities of these data.




3-D Magnetic Field Geometry of the October 28, 2003 ICME: Comparison with SMEI White-Light Observations
E.A. Jensen (Institute of Geophysics and Planetary Physics, UCLA, Los Angeles, CA)
T. Mulligan (Space Sciences Lab., The Aerospace Corp., Los Angeles, CA)
B.V. Jackson (UCSD/CASS, La Jolla, CA)
M. Tokumaru (Solar-Terrestrial Environment Lab., Nagoya University, Toyokawa, Japan

Multiple reconstructions of the October 28-29, 2003 CME/ICME using white-light observations, ground-based cosmic-ray and in situ magnetic field flux rope modeling show two possible flux-rope configurations that pass Earth on opposite sides of the central symmetry axis of the disturbance. An analysis of flux rope model geometries initiated over a wide range in parameter space to test the uniqueness of the single spacecraft inversion reveals the fit is degenerate over a range of impact parameters such that two solutions are obtained. In one case (fit A) the disturbance passes Earth to the west of the rope center with the rope axis at a low inclination of 20 deg to the ecliptic, similar to the ground-based flux rope analysis by Kuwabara et al. (2004). In the second case (fit B) the disturbance passes Earth to the east of the flux rope axis, with the rope axis more highly inclined at 42 deg from the ecliptic, consistent with the SMEI white-light analysis of Jackson et al. (2006). The current densities in both solutions indicate a nearly force-free structure. Multipoint studies of ICMEs show the radius of curvature in the plane of the rope is between that of a dipole field line connected to the Sun and that of a circular field line connected to the Sun. Assuming a dipole field geometry for the large-scale axial field curvature of the rope results in a 3-D reconstruction for case B that is consistent with the loop structure and observed speed in the white-light LASCO images and SMEI density reconstruction, but not for case A. Multipoint measurements of large-scale solar wind transients is one of the key objectives of the Stereo mission, allowing more accurate 3-D reconstructions of in situ data for comparison with white-light observations. Until they become available, the large-scale axial field orientation and loop geometry of these rope reconstructions provides another tool to constrain magnetic flux rope fits of ICMEs using single spacecraft measurements.




Goals and Progress of the LWS Focused Science Topic on the CME--ICME Connection
Z. Mikic (SAIC, San Diego, CA)
C. DeForest (SWRI, Boulder, CO)
R. DeVore (NRL, Washington, DC)
M. Georgoulis (JHU/APL, Laurel, MD)
B.V. Jackson (UCSD/CASS, La Jolla, CA
N. Nitta (LMSAL, Palo Alto, CA)
V. Pizzo (NOAA/SEC, Boulder, CO)
D. Odstrcil (NOAA/SEC, Boulder, CO

Our team addresses the NASA Living With a Star (LWS) Focused Science Topic "to determine the solar origins of the plasma and magnetic flux observed in an interplanetary Coronal Mass Ejection (ICME)." In short, this team is examining the CME--ICME connection. Our team was formed as a result of awards from the LWS Targeted Research and Technology competition in the fall of 2004. Our team is investigating the detailed relationship between the plasma and magnetic fields in active regions, the source regions of CMEs, and subsequent in situ measurements in interplanetary magnetic clouds. We plan to study this connection through detailed numerical simulations of CME initiation and propagation, theoretical investigations, and studies of the properties of active regions, CMEs, and magnetic clouds. We will discuss the goals of our team, how it fits into NASA's missions, and our progress so far. Research supported by NASA's Living With a Star Program.




CME Brightness at Large Elongations: Application to LASCO and SMEI Observations
A. Vourlidas (Naval Research Lab., Washington, DC)
D.F. Webb (ISR, Boston College, Chestnut Hill, MA
J.S. Morrill (Naval Research Lab., Washington, DC)
B.V. Jackson (UCSD/CASS, La Jolla, CA)

The traditional analysis of the CME brightness relied on the assumption that all lines of sight through the CME were parallel due to the large distance between the observer and the event. However, this assumption is not correct when CME observations at large distances from the Sun are concerned. In a recent paper (Vourlidas and Howard, 2006) we have outlined the proper geometry and presented a few theoretical predictions about the brightness evolution of CME launched at various angles relative to the Sun-observer line. In this talk, we use LASCO and SMEI observations of the same events to test our predictions and see how we can use our theoretical framework to interpret the observed CME structures.




Off-radial flow of the solar wind from EISCAT and MERLIN IPS observations
M.M. Bisi (UCSD/CASS, La Jolla, CA)
A.R. Breen, R.A. Fallows, G.D. Dorrian and R.A. Jones
(Inst. of Mathematical and Physical Sciences, Univ. of Wales, Aberystwyth

G. Wannberg (EISCAT Scientific Association, Kiruna)
P. Thomasson and C. Jordan (Jodrell Bank Observatory, University of Manchester)

Interplanetary scintillation (IPS) observations provide a view of the solar wind at all heliographic latitudes inside the Earth's orbit down to the SOHO|LASCO C2 field-of-view. It can be used to study the evolution of the solar wind as it expands out into interplanetary space. Presented here are results from extremely long-baseline IPS measurements using the EISCAT system located in northern Scandinavia and the MERLIN system located in the United Kingdom. Extremely long-baseline IPS observations provide increased velocity resolution in the line-of-sight and a better indication of off-radial solar wind outflow. The results presented in this presentation clearly show equator-ward over-expansion of the fast solar wind at heliocentric distances ranging from 24 to 84 solar radii - implying divergence of the large-scale magnetic field at interplanetary distances in the fast solar wind. We also present case studies showing flow rotation during the passage of a magnetic cloud and deviation in the direction of solar wind flow across stream interfaces.




SHINE 2006 Workshop
Midway, UT, July 31-August 4, 2006



The UCSD/SMEI Data Processing Pipeline
P.P. Hick, A. Buffington and B.V. Jackson (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) measures a photometric white-light response of the interplanetary medium from Earth-orbit over most of the sky in near real time. In the first three years of operation the instrument has recorded the inner heliospheric response to several hundred CMEs. We illustrate the main data reduction steps used to convert the SMEI data from the raw CCD images to photometrically accurate maps of the sky brightness. This includes: integration of new data into the SMEI data base; conditioning to remove from the raw CCD images an electronic offset and dark current pattern; assembly of the CCD images in a high-resolution sidereal grid using known spacecraft pointing information. The high-resolution grid is reformatted to a lower-resolution set of sidereal maps of sky brightness. From these we remove bright stars, background stars, and a zodiacal cloud model. Time series at selected sidereal locations are extracted and processed further to remo ve aurorae, brigth stars, unresolved star light (primarily from the galactic plane) and other unwanted signals. Time series (with a long-term base removed) are currently used in 3D tomographic reconstructions of the solar wind density structure in the inner heliosphere. The data processing is distributed over multiple PCs running Linux, and, runs as much as possible automatically using recurring batch jobs ('cronjobs') mostly written in Python. The core data processing routines are written in Fortran, C++ and IDL.

PDF Poster


Mass and Energies of the 20 January 2005 CME From Solar Mass Ejection Imager (SMEI) Analyses
B.V. Jackson, P.P. Hick and A. Buffington (UCSD/CASS)

Solar Mass Ejection Imager (SMEI) brightness measurements are analyzed to determine 3D volumetric densities. Although more information is gleaned from heliospheric observations when there is also interplanetary scintillation (IPS) velocity data present, the volumetric density information can be obtained from the SMEI instrument-alone 3D analysis of this data set. Here we present analyses of these 3D heliospheric volumetric solar wind density and velocity data. We use this system to measure the distribution of structure and provide 3D mass of the ejecta associated with the large CME viewed in SMEI observations for which the primary mass moves to the northwest of the Sun following the 20 January 2005 CME event observed earlier in LASCO coronagraph observations.




Space Weather Week
Boulder, CO, April 25-28, 2006



SMEI Data Processing From Raw CCD Frames to Photometrically Accurate Full-Sky Maps
P.P. Hick, A. Buffington and B.V. Jackson (UCSD/CASS)

Solar Mass Ejection Imager (SMEI) densities can now be rendered volumetrically from brightness obtained from the SMEI instrument throughout its time period of operation. Although more information is gleaned from heliospheric observations when there is also interplanetary scintillation (IPS) velocity data present, the volumetric density information can be obtained from the SMEI instrument-alone 3D analysis of this data set. Here we present a volume rendering system developed for the real time visualization and manipulation of these 3D heliospheric volumetric solar wind density and velocity data. We use this system to measure the distribution of structure and provide 3D mass of the ejecta associated with the large CME viewed in SMEI observations that moves to the northwest of the Sun following the January 20, 2005 event observed earlier in LASCO coronagraph observations.




Interactive Visualization of Volumetric Data from the Solar Mass Ejection Imager (SMEI)
B.V. Jackson, P.P. Hick and A. Buffington (UCSD/CASS)
D. Odstrcil (University of Colorado)

The Solar Mass Ejection Imager (SMEI) measures a photometric white-light response of the interplanetary medium from Earth-orbit over most of the sky in near real time. In the first three years of operation the instrument has recorded the inner heliospheric response to several hundred CMEs (including the May 28, 2003 and the October 28, 2003 halo CMEs). We present the principal data reduction steps used to process the SMEI data from the time the raw CCD images become available to their final assembly into photometrically accurate maps of the sky brightness. This includes: integration of new data into the SMEI data base; conditioning to remove from the raw CCD images an electronic offset and dark current pattern; placement of the CCD images onto a high-resolution sidereal grid using known spacecraft pointing information. The high-resolution map is reformatted to a lower-resolution set of sidereal maps of sky brightness. From these we remove bright stars, background stars, and a zodiacal cloud model. Time series at selected sidereal locations are extracted and processed further to remove aurorae, brigth stars, unresolved star light (primarily from the galactic plane) and other unwanted signals. Time series (with a long-term base removed) are currently used in 3D tomographic reconstructions.




2005 Fall AGU Meeting
San Francisco, CA, December 5 - 9, 2005



SMEI: An spaceborne observatory for heliospheric remote sensing
P.P. Hick, B.V.Jackson and A. Buffington (UCSD/CASS)

The Solar Mass Ejection Imager provides measurements of the Thomson scattering brightness with near-full sky coverage from Earth orbit. These observations allow three-dimensional reconstruction of the solar wind density and velocity in the inner heliosphere. We discuss how these observations provide context for in situ solar wind observations from other "Great Observatory" satellites near Earth (ACE), other planets (Mars Orbiter) and deep space spacecraft (Ulysses).




Global 3-D Solar Wind Analysis of Halo CMEs Using Interplanetary Scintillation
(IPS) Remote Sensing and its Comparison at Mars

J A. Boyer, B.V. Jackson, A. Buffington, P.P. Hick, Y. Yu (UCSD/CASS)
D.H. Crider (Catholic Univ. of America, Gibsonville, NC)

The Interplanetary Scintillation (IPS) process allows observation of the inner heliospheric response to CMEs in scintillation level and velocity. With the help of our colleagues in STELab, Japan, we have developed near real time access of these data for use in space weather forecasting. We use a 3D reconstruction technique that obtains perspective views from outward-flowing solar wind as observed from Earth by iteratively fitting a kinematic solar wind model using the IPS observations. This 3D modeling technique permits us to reconstruct the density and velocity structure of CMEs, and other interplanetary transient structure at low resolution (with a one day cadence, and at a 20 deg. latitudinal and longitudinal heliographic resolution). Here we explore the use of this technique to reproduce the solar wind pressure observed at Mars following the aftermath of halo (Earth-directed) CMEs. These CMEs include one that erupted from the Sun on May 27, 2003 and another on October 28, 2003 both of which produced a large response at Mars. In addition we explore the response at Mars and our reconstruction of "backside" (as seen from Earth) halo CMEs.




Solar Mass Ejection Imager (SMEI) Solar Wind 3-D Analysis of the January 20, 2005 CME
B.V. Jackson, A.,Buffington, P.P. Hick and Y. Yu (UCSD/CASS)
D. Webb (ISR, Boston College, Chestnut Hill, MA)

The Solar Mass Ejection Imager (SMEI) has observed the inner heliospheric response in white light from over 200 CMEs. One of these, on January 20, 2005, produced one of the largest Solar Energetic Particle events ever recorded. We show SMEI orbital difference images and the 3D solar wind reconstruction of this well-observed CME, and demonstrate how we can track its outward motion from approximately 20 deg. from the Sun until it vanishes in the SMEI field of view in the direction of the Ulysses spacecraft. Our 3D reconstruction technique is used to obtain perspective views from outward-flowing solar wind as observed from Earth by iteratively fitting a kinematic solar wind density model using the SMEI white light observations. This 3D modeling technique permits us to separate the heliospheric response in SMEI from background noise, and to estimate the 3D structure and transient heliospheric components of the CME and its speed and mass. We then determine the total energy of the CME that can be used as input to determine the total energy output of the event. More information about the spatial extent and energetics of this CME event can be determined by measurements in-situ from the Ulysses spacecraft that was beyond 5 AU and about 35° west of Earth. Ulysses first detected an extremely fast CME response at the spacecraft 7 days following the event on the Sun and the transient flow continued for several days. The SMEI 3D reconstruction shows the event as it passes Earth to the west and helps to disentangle the CME structure. This will allow a better understanding of which portions of the CME intersect Ulysses, and the 3D trajectories of several CMEs observed earlier in coronagraph and SMEI data.




2005 Joint Assembly AGU, SEG, NABS and SPD/AAS
New Orleans, LA, May 23 - 27, 2005



Preliminary Three Dimensional CME Mass and Energy Using Solar Mass Ejection Imager (SMEI) Data
B.V.Jackson, A. Buffington, P.P.Hick and Y. Yu (UCSD/CASS)
D. Webb, D. Mizuno and T. Kuchar (Boston College)

White-light Thomson scattering observations from the Solar Mass Ejection Imager (SMEI) have recorded the inner heliospheric response to several hundred CMEs including the May 28, 2003 halo CME, the October 28, 2003 halo CME, and numerous other heliospheric structures. Here we show the extent of several well-observed CMEs in SMEI observations, and show how we are able to track events from their first measurements in SMEI approximately 20° from the solar disk until they vanish from the SMEI 180° field of view. Several portions of large CMEs observed by the LASCO coronagraphs can be tracked into the interplanetary medium associated with the initial CME response and the underlying erupting prominence structure. We use a 3D reconstruction technique that obtains perspective views from outward-flowing solar wind as observed from Earth, iteratively fitting a kinematic solar wind density model using the SMEI white light observations and, when available, the Solar-Terrestrial Environment Laboratory (STELab), Japan interplanetary scintillation (IPS) velocity data. This 3D modeling technique allows us to separate the heliospheric response in SMEI from background noise, and to estimate the 3D structure of the CME and its mass. For instance, the analysis shows and tracks outward the northward portion of the loop structure of the October 28, 2003 CME observed as a halo in LASCO images that passes Earth on October 29. We determine an excess mass for this structure of 6.7 x 1016 g and a total mass including an ambient background of 8.3 x 1016 g. The very fast structure compared in a 3D pixel to pixel comparison with the IPS velocity data gives a kinetic energy for the northward portion of this event of 2.0 x 1034 erg as it passes Earth.




Space Weather Week
Boulder, CO, April 5 - April 8, 2005



Interactive Visualization of Solar Mass Ejection Imager (SMEI) and Interplanetary Scintillation (IPS) Volumetric Data
B.V. Jackson, Y. Yu, P.P. Hick, A. Buffington (UCSD/CASS
D. Odstrcil (University of Colorado)

We present a volume rendering system developed for the real time visualization and manipulation of 3D heliospheric volumetric solar wind density and velocity data obtained from the Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS) velocities over the same time period. Our system exploits the capabilities of the VolumePro 1000 board from TeraRecon, Inc., a low-cost 64-bit PCI board capable of rendering up to a 512-cubed array of volume data in real time at up to 30 frames per second on a standard PC. Many volume-rendering operations have been implemented with this system such as stereo/perspective views, animations of time-sequences, and determination of CME volumes and masses. In these visualizations we highlight two time periods where halo CMEs were observed by SMEI to engulf Earth, on May 30, 2003 and on October 29, 2003. We demonstrate how this system is used to measure the distribution of structure and provide 3D mass for individual CME features, including the ejecta associated with the large prominence viewed moving to the south of Earth following the late October CME. We will also demonstrate how a simple Internet connection can be used to remotely manipulate and share these volumes across the continent and the world to interactively view them.




205th AAS Meeting
San Diego, CA, January 9 - 13, 2005



Preliminary Three Dimensional Reconstruction of CMEs Using Solar Mass Ejection Imager (SMEI) Data
B.V.Jackson, A. Buffington, P.P.Hick and X. Wang (UCSD/CASS)

White-light Thomson scattering observations from the Solar Mass Ejection Imager (SMEI) have recorded the inner heliospheric response to the October 28, 2003 CME. Here we detail the extent of this particular CME event in SMEI observations, and we show how we are able to track the event from its first measurement approximately 20° from the solar disk until it fades away in the SMEI 180° field of view. Several portions of this CME that can be tracked into the interplanetary medium are associated with the initial CME response and the underlying erupting prominence structure. We employ a 3D reconstruction technique that provides perspective views from outward-flowing solar wind as observed from Earth. This is accomplished by iteratively fitting the parameters of a kinematic solar wind density model to the SMEI white light observations and to Solar-Terrestrial Environment Laboratory (STELab), interplanetary scintillation (IPS) velocity data. This 3D modeling technique enables separating the true heliospheric response in SMEI from background noise, and reconstructing the 3D heliospheric structure as a function of time. These reconstructions allow both separation of the 28 October CME from other nearby heliospheric structure and a determination of its mass. The preliminary SMEI white light calibration indicates a total mass of 6 x 1016 g for the ejecta associated with the prominence eruption. The total mass of this CME including possible associated nearby structures may have been as much as ~2 x 1017 g of inner heliospheric response spread over much of the Earthward-facing hemisphere.




Near Real-Time Photometric Data Processing for the Solar Mass Ejection Imager (SMEI)
P. Hick, A. Buffington and B.V. Jackson (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) records a photometric white-light response of the interplanetary medium from Earth over most of the sky in near real time. In the first two years of operation the instrument has recorded the inner heliospheric response to several hundred CMEs, including the May 28, 2003 and the October 28, 2003 halo CMEs. In this preliminary work we present the techniques required to process the SMEI data from the time the raw CCD images become available to their final assembly in photometrically accurate maps of the sky brightness relative to a long-term time base. Processing of the SMEI data includes integration of new data into the SMEI data base; a conditioning program that removes from the raw CCD images an electronic offset ("pedestal") and a temperature-dependent dark current pattern; an "indexing" program that places these CCD images onto a high-resolution sidereal grid using known spacecraft pointing information. At this "indexing" stage further conditioning removes the bulk of the the effects of high-energy-particle hits ("cosmic rays"), space debris inside the field of view, and pixels with a sudden state change ("flipper pixels"). Once the high-resolution grid is produced, it is reformatted to a lower-resolution set of sidereal maps of sky brightness. From these sidereal maps we remove bright stars, background stars, and a zodiacal cloud model (their brightnesses are retained as additional data products). The final maps can be represented in any convenient sky coordinate system. Common formats are Sun-centered Hammer-Aitoff or "fisheye" maps. Time series at selected locations on these maps are extracted and processed further to remove aurorae, variable stars and other unwanted signals. These time series (with a long-term base removed) are used in 3D tomographic reconstructions. The data processing is distributed over multiple PCs running Linux, and, runs as much as possible automatically using recurring batch jobs ('cronjobs'). The batch scrips are controlled by Python scripts. The core data processing routines are written in several computer languages: Fortran, C++ and IDL.




Photometric Calibration for the Solar Mass Ejection Imager (SMEI)
A. Buffingtom, A.C. Smith, B.V. Jackson, and P. Hick (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) was designed to record a photometric white-light response of the interplanetary medium from Earth over most of the sky in near real time, using Thomson scattered sunlight. In its first two years the instrument has observed several hundred Coronal Mass Ejections. Quantitative interpretations of these data requires that the Analog Data Units (ADUs) of the instrument's CCD responses be converted to an effective stellar brightness. The present work provides a preliminary report on establishing this relationship. An appropriate unit here is an "S10", the equivalent brightness of a 10th magnitude star spread over one square degree. The relationship between ADUs and S10s is established by using the SMEI response to bright stars having known visual magnitude and spectral type. These latter are converted to a "SMEI magnitude" by integrating the various star's spectra over the nominal SMEI bandpass, which extends between 0.4 and 1.1 microns and peaks at 0.7 microns, to obtain a spectral scaling factor which is set to unity for G-type stars and relates visual magnitudes to SMEI magnitudes. The final overall conversion factor is then determined from the ADU measurements of the individual stars. This work was supported in part by NSF contract ATM0331513 and NASA grant NAG 5-134543.




Interactive Visualization of Solar Mass Ejection Imager (SMEI) Volumetric Data
X. Wang, P. Hick and B.V. Jackson (UCSD/CASS)

We present a volume rendering system developed for the real time visualization and manipulation of 3D heliospheric volumetric solar wind density and velocity data obtained from the Solar Mass Ejection Imager (SMEI) and interplanetary scintillation (IPS) velocities over the same time period. Our system exploits the capabilities of the VolumePro 1000 board from TeraRecon, Inc., a low-cost 64-bit PCI board capable of rendering up to a 512-cubed array of volume data in real time at up to 30 frames per second on a standard PC. Many volume-rendering operations have been implemented with this system such as stereo/perspective views, animations of time-sequences, and determination of CME volumes and masses. In these visualizations we highlight two time periods where halo CMEs were observed by SMEI to engulf Earth, on May 30, 2003 and on October 29, 2003. We demonstrate how this system is used to measure the distribution of structure and provide 3D mass for individual CME features, including the ejecta associated with the large prominence viewed moving to the south of Earth following the late October CME.




2004 Fall AGU Meeting
San Francisco, CA, December 13 - 17, 2004



Heliospheric Photometric Images and 3D Reconstruction from the Solar Mass Ejection Imager (SMEI) Data
B.V.Jackson, A. Buffington and P.P.Hick (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) experiment is fixed to the Coriolis spacecraft and views the sky above Earth using sunlight-rejecting baffles and CCD camera technology. SMEI was designed to provide precise photometric white light images over most of the sky on each 102-minute Earth orbit. The brightness sky maps of the inner heliosphere indicate a rich variety of electron density structures that are produced by the material that propagates through it and its interaction with ambient structures. We present some of the preliminary results of the analysis of these photometric SMEI observations derived by modeling the white light observations such that most of the contaminant signals: stars, the zodiacal cloud and high-energy particle variations are removed. We will also show some of the 3D reconstructions that allow this contaminant signal removal using both interplanetary scintillation (IPS) and SMEI data.




Systematic Error Reduction and Photometric Calibration for the Solar Mass Ejection Imager (SMEI)
A. Buffington, B.V. Jackson and P.P. Hick (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) instrument provides white-light photometric maps covering most of the sky each orbit of the Coriolis spacecraft. The SMEI differential photometry specification is 0.1% for each 1 square degree sky bin. A labyrinthine baffle reduces scattered sunlight, but for a portion of the data a background residue must also be subtracted to finally reach this specification. We describe this process, and further discuss how bright stars are used to determine an appropriate conversion from the CCD-camera data units to sky surface brightness. Also, the CCD in the camera viewing closest to the Sun operates significantly warmer than expected, which gives rise to a changing population of "hot pixels". We describe a data-analysis process which significantly alleviates the photometric impact of this.




Zodiacal Light Analysis and Removal From the Solar Mass Ejection Imager (SMEI) Data
S. Simon, B.V. Jackson, A. Buffington, P.P. Hick and A.C. Smith (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) experiment provides white-light photometric maps covering most of the sky each orbit of the Coriolis spacecraft. The SMEI differential photometry specification is 0.1% for each 1 square degree sky bin, and was designed to provide precise photometric white light images over most of the sky on each 102-minute Earth orbit in order to map heliospheric structures. One of the brightest contaminant signals observed in SMEI is zodiacal light brightness that must be modeled and subtracted from the data in order to provide heliospheric sky maps free from large background changes. We have devised a technique to remove zodiacal dust brightness from the SMEI maps, and in order to do so accurately measure the asymmetry of the equatorial dust to the ecliptic plane as well as the Gegenschein brightness throughout the year. We present preliminary analyses of these observations for specific intervals during the one and a half year lifetime of SMEI.




Comparison of Solar Mass Ejection Imager (SMEI) White Light Observations with IPS Velocity
B.V. Jackson, A. Buffington, P.P. Hick (UCSD/CASS)
M. Kojima and M. Tokumaru (STELab, Nagoya Univ., Japan)

The Solar Mass Ejection Imager (SMEI) experiment is fixed to the Coriolis spacecraft and views the sky above Earth using sunlight-rejecting baffles and CCD camera technology. SMEI was designed to provide precise photometric white light images over most of the sky on each 102-minute Earth orbit. The brightness sky maps of the inner heliosphere indicate a rich variety of electron density structures that are produced by the material that propagates through it and its interaction with ambient structures. We present some of the preliminary results of the analysis of these photometric SMEI observations derived by 3D reconstructions that allow contaminant signal removal using both interplanetary scintillation (IPS) velocities and SMEI data. We use these analyses to compare preliminary SMEI tomographic white-light results with IPS velocity for the same time intervals.




Three-dimensional structure of compound interplanetary transients associated with 27-28 May 2003 coronal mass ejections
M. Tokumaru, M. Kojima, K. Fujiki, M. Yamashita (STELab, Nagoya Univ., Japan)
B.V. Jackson, A. Buffington, P.P. Hick (UCSD/CASS)

We have investigated the global features of interplanetary (IP) disturbances associated with 27-28 May coronal mass ejection (CME) events using interplanetary scintillation (IPS) measurements of the Solar-Terrestrial Environment Laboratory (STEL). Our IPS data taken between 2003 May 28 22h UT and May 29 7h UT showed a set of complex feature of IP disturbances, and most of them are regarded as IP consequences of two full-halo CMEs which occurred in association with the X1.3/2B flare on May 27 23:07 UT and the X3.3 flare on May 28 00:27 UT. Some components of the IP disturbances were discriminated from the IPS data by making the model fitting analysis iteratively. One of the components was an Earth-directed one, which appears to correspond to the IP shock observed by ACE on May 29 18:30 UT. Other components were obliquely propagating ones, which either preceded or followed the Earth-directed one. The global features deduced here are generally in agreement with heliospheric reconstructions made from Solar Mass Ejection Imager (SMEI) measurements.




204th AAS Meeting
Denver, CO, May 30 - June 3, 2004



Coronal Mass Ejection Masses From CMEs Identified in Interplanetary Scintillation (IPS) Tomography and LASCO Coronagraph Images
S.A.Rappoport, B.V.Jackson, P.P.Hick, A.Buffington (UCSD/CASS)
A.Vourlidas (NRL, Washington, DC)

To optimize the information from individual radio source observations of the sky covering large elongations, we have developed a Computer-Assisted Tomography (CAT) program. We fit STELab (Nagoya University, Japan) interplanetary scintillation (IPS) observations to a time-dependent, three-dimensional heliospheric model. These observations allow us to create "sky maps" covering 10° to 80° in elongation, in which we can track CMEs observed earlier in LASCO coronagraph images. These events have approximately the same shapes and extents as observed closer to the Sun. Here we map several CMEs in 3-dimensions as they move outward to 1 AU. Masses for each of the events are determined from the reconstruction analysis and are compared with plane of the sky masses obtained from calibrated LASCO coronagraph images.




The Solar Mass Ejection Imager (SMEI) and its potential as a precision time-series photometer
A. Buffington, B.V. Jackson and P.P. Hick (UCSD/CASS)
Alan Penny (Space Science Dept., Rutherford-Appleton Lab, Chilton, UK.
G.M. Simnett (School of Physics and Space Research, Univ. of Birmingham, UK)

The Solar Mass Ejection Imager (SMEI) was launched in January 2003 into Earth orbit. SMEI is designed to observe heliospheric structures illuminated by Thomson-scattered sunlight. The design specification for SMEI is 0.1% in differential photometry for bright unresolved objects, to enable star removal from the heliospheric maps. Such a near-Earth imager will also provide photometric time-series measurements of these stars as a by-product of this removal process. For each 101-minute orbit, SMEI will deliver near complete sky maps having an expected (1s) photometric resolution of about the equivalent of an 11th magnitude star in a square degree. We will report on progress in establishing the photometric calibrations for the SMEI cameras, and discuss SMEI's potential for delivering photometric time-series measurements, which data can then be applied to the study of variable stars, eclipsing stellar systems, and to search for extrasolar planets by the occultation method.




Space Weather Week
Boulder, CO, April 13 - April 16, 2004



Interactive Visualization of Transient Solar Wind Phenomena for Space Weather Applications
C.X. Wang, P.P. Hick, B.V. Jackson (UCSD/CASS

We present a volume rendering system developed for the visualization, and manipulation of 3D heliospheric volume data, such as solar wind density, velocity and magnetic field. Our system exploits the capabilities of the VolumePro 1000 board from TeraRecon, Inc., a low-cost 64-bit PCI board capable of rendering a 512-cubed array of volume data in real time at up to 30 frames per second on a standard PC. Many operations have been implemented such as stereo/perspective views, animations of time-sequences, and determination of CME volumes and masses. We will show examples of three-dimensional heliospheric volumes from tomographic reconstructions of density and velocity using real-time interplanetary scintillation (IPS) data. In the near future we expect to add reconstructions based on the all-sky observations from the recently launched Solar Mass Ejection Imager and employ our system to interactively analyze and visualize the abundant information embedded in these data.




AGU Fall Meeting 2003
San Francisco, USA, December 8 - December 12, 2003



The Solar Mass Ejection Imager (SMEI) Mission
B.V. Jackson, A. Buffington, B.V. Jackson and P. Hick (UCSD/CASS)
P. Holladay, P, J.C. Johnston, S.W. Kahler, S W, J. Mozer, S. Price,
R.R. Radick and D. Sinclair (AFRL, VS)
G.M. Simnett, C.J. Eyles, M.P. Cooke, J. Tappin,
(School of Physics and Space Research, University of Birmingham, Birmingham, UK)
N.R. Waltham
(Space Science Dept., Rutherford-Appleton Lab., Chilton, UK)
T. Kuchar, D. Mizuno and D.F. Webb (ISR, Boston College)

We have designed, built and launched into near-Earth orbit a Solar Mass Ejection Imager (SMEI) capable of observing sunlight that has Thomson-scattered from heliospheric structures of time-varying density. SMEI is designed to observe heliospheric structures such as coronal mass ejections, corotating structures and shock waves, to elongations greater than 90° from the Sun. The instrument was inspired by the heliospheric imaging capability demonstrated by the zodiacal light photometers of the Helios spacecraft. The instrument makes effective use of in situ solar wind data from spacecraft in the vicinity of the imager by extending observations to the surrounding environment and back to the Sun. A near-Earth imager can provide up to three days warning of the arrival of a mass ejection from the Sun. In combination with other imaging instruments in deep space, or alone by making some simple assumptions about the outward flow of the solar wind, SMEI can provide a tomographic analysis of the heliospheric structures surrounding it.




The Solar Mass Ejection Imager (SMEI)
G.M. Simnett, C.J. Eyles, M.P. Cooke,
(School of Physics and Space Research, University of Birmingham, Birmingham, UK)
N.R. Waltham, J.M. King
(Space Science Dept., Rutherford-Appleton Lab., Chilton, UK)
B.V. Jackson, A. Buffington, B.V. Jackson and P. Hick (UCSD/CASS)
P. Holladay (AFRL, VS)
P.A. Anderson (Astronomy Dept., Boston College, Boston, US)

The Solar Mass Ejection Imager (SMEI) has been designed to detect and forecast the arrival of solar mass ejections and other heliospheric structures which are moving towards the Earth. We describe the instrument, which was launched into a Sun-synchronous polar orbit on 6 January, 2003 on board the US DoD Coriolis spacecrafth. SMEI contains three CCD cameras, sensitive over the optical waveband, each with a field-of-view of 60°×3°. The sensitivity is such that it will detect changes in sky brightness equivalent to a tenth magnitude star in one square degree of sky. Each camera takes an image every 4s and the normal telemetry rate is 128 kbits/s. SMEI has a photometric accuracy of around 0.1%. In addition to solar mass ejections, images of stars and the zodiacal cloud are measured to this photometric accuracy once/ orbit (102 minutes)..




IPS/SMEI potential joint observations
M. Tokumaru, M. Kojima, K. Fujiki,
STE Lab, Nagoya University, Toyokawa, Japan
B.V. Jackson and P. Hick (UCSD/CASS)

Interplanetary scintillation (IPS) measurements are known as one of remote-sensing techniques which enable us to gain access to global features of the solar wind (e.g. quasi-stationary corotating structures, transient streams associated with CMEs). We have carried out a long-term collaboration on the reconstruction of the heliospheric features from IPS measurements made with the 327 MHz four-station system of the Solar-Terrestrial Environment Laboratory (STEL), Nagoya University. Under the collaboration, we have developed the computer-assisted tomography (CAT) analysis method, which allows us to retrieve the 3D distribution of the solar wind velocity and density from IPS data. We also have been making the real-time reconstruction experiment of heliospheric features using STEL IPS data and the CAT method. Based on these results, we propose here the joint observations of IPS and SMEI. The SMEI is a powerful tool to investigate the global heliospheric features, and its capability is complementary to one of IPS observations; That is, SMEI observations provide a high-resolution image of the solar wind density distribution, while IPS observations provide reliable estimates of the solar wind velocity. Therefore, a combination of IPS and SMEI observations is essential for achieving a precise reconstruction of global heliospheric (velocity and density) features by the CAT analysis.




Interactive Visualization of Transient Solar Wind Phenomena for Space Weather Applications
X. Wang, P. Hick and B.V. Jackson (UCSD/CASS)

We present a volume rendering system developed for the visualization and manipulation of 3D heliospheric volume data such as solar wind density, velocity and magnetic field. Our system exploits the capabilities of the VolumePro 1000 board from TeraRecon, Inc., a low-cost 64-bit PCI board capable of rendering a 512-cubed array of volume data in real time at up to 30 frames per second on a standard PC. Many operations have been implemented such as stereo/perspective views, animations of time-sequences, and determination of CME volumes and masses. We will show examples of three-dimensional heliospheric volumes from tomographic reconstructions of density and velocity using real-time interplanetary scintillation (IPS) data. In the near future we expect to add reconstructions based on the all-sky observations from the recently launched Solar Mass Ejection Imager and employ our system to interactively analyze and visualize the abundant information embedded in these data.




Space Performance of the Multistage Labyrinthine SMEI Baffle
A. Buffington, B.V. Jackson and P. Hick (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) was launched on 6 January 2003, and shortly thereafter raised to a nearly circular orbit at 840 km. Three SMEI CCD cameras on the zenith-oriented CORIOLIS spacecraft cover most of the sky beyond about 20° from the Sun, each 102-minute orbit. Data from this instrument will ultimately provide precision visible-light photometric sky maps. Once starlight and other constant or slowly varying backgrounds are subtracted, the residue is mostly sunlight that has been Thomson-scattered from heliospheric electrons. These maps will enable 3-dimensional tomographic reconstruction of heliospheric density and velocity. This analysis requires 0.1% photometry and background-light reduction below one S10 (the brightness equivalent of a 10th magnitude star per square degree). Thus 10-15 of surface-reduction is required relative to the solar disk. The SMEI labyrinthine baffle provides roughly 10-10 of this reduction; the subsequent optics provides the remainder. We analyze data covering a range of angles between the SMEI optical axis and the Sun, or the Moon, to evaluate the full system's stray-light rejection performance.




Stellar Variability Studies with SMEI
A.J. Penny (Rutherford Appleton Lab., UK)
B.V. Jackson, A. Buffington, and P. Hick (UCSD/CASS)
S.W. Kahler, S. Price, J.C. Johnston, P. Holladay, D. Sinclair,
R.R. Radick, J.C. Mozer, AFRL/VS, Hanscom AFB, US)
P. Anderson (Boston University, Boston, US)
G.M. Simnett, C.J. Eyles, M.P. Cooke, J. Tappin,
(University of Birmingham, Birmingham, UK)
N.R. Waltham (Rutherford Appleton Lab., UK)
T. Kuchar, D. Mizuno, D.F. Webb (Boston College, Boston, US)

The Solar Mass Ejection Imager (SMEI) instrument images most of the sky every 105 minutes. From this unique dataset, the brightnesses of stars down to and below the eight magnitude can be measured to investigate their variability. This paper presents the methods developed to extract the stellar brightnesses, and the accuracies obtained as a function of brightness and crowding. Example lightcurves are given.





Recent Comparative Analyses of the CSSS UCSD Tomographic Solar Wind Model with in situ Spacecraft Observations
Tamsen Dunn, Bernard V. Jackson, P. Paul Hick (UCSD/CASS)

Our tomographic techniques developed over the last few years are based on kinematic models of the solar wind. This allows us to determine the large-scale three-dimensional extents of solar wind structures using interplanetary scintillation (IPS) observations and Thomson scattering brightness data in order to forecast their arrival at Earth in real time. We are specifically interested in a technique that can be combined with observations presently available from IPS velocity data and with observations which are now becoming available from the Solar Mass Ejection Imager. We use solar surface magnetogram data, and a source surface provided by the Stanford Current-Sheet Source Surface model, to provide input to the UCSD tomography program. The UCSD tomography program extrapolates the magnetic field out to and beyond Earth The latest results are compared with in situ data. Real time projections of these data are available on our web site at: http://cassfos02.ucsd.edu/solar/forecast/index_v_n.html and http://cassfos02.ucsd.edu/solar/forecast/index_br_bt.html
This work was supported at UCSD through MURI grants F49620-01-1-0360 and F49620-01-1-0335, and NSF grant ATM-0208443.




AAS 201st Meeting
Seattle, WA, January, 2003



Coronal Mass Ejections Identified in Interplanetary Scintillation (IPS) Tomography and in LASCO Coronagraph Images
S.A. Rappoport, P.P. Hick, B.V. Jackson (CASS/UCSD)

Coronal mass ejections (CMEs), including halo CMEs, can be observed in interplanetary scintillation (IPS) data. To optimize the information from radio source observations, we model them using a time-dependent three-dimensional tomography program. We depict this heliospheric model as a series of "sky map" images that cover elongations extending from 10° to 80°. These IPS maps show CMEs observed earlier in the LASCO coronagraph images with approximately the same shapes and extents that were seen closer to the Sun. Here, a series of these CME events, including halo CMEs, are mapped as they move outward to distances as great as 1 AU.




Remote-Sensing of the Solar Wind: A Space Weather Application
P. Hick, S. Rappoport, B.V. Jackson, T. Dunn and X. Wang (UCSD/CASS)

Remote sensing observations of the solar wind in the inner heliosphere fill an observational gap between near-Sun remote sensing and near-Earth in-situ data. We use heliospheric tomography to follow solar disturbances from Sun to Earth as the basis for a real-time space weather system. Over the past few years interplanetary scintillation observations from the Solar-Terrestrial Laboratory at Nagoya University, Japan, provided the main source of data. In the near future Thomson scattering observations from the recently launched Solar Mass Ejection Imager (SMEI) will be added. Here we show some recent developments in the visualization techniques used to process the volume data sets produced by the tomographic analyis: solar wind density, velocity and magnetic field. 3D visualization is based on an image rendering engine written in the IDL programming language. In addition, we use hardware-based volume rendering with the Volume Pro PCI board from TeraRecon. This board renders 4D volume data (three spatial, plus the time dimension) in real-time, allowing interactive manipulation of evolving (time-dependent) data sets. This work was supported through NASA grant NAG5-9423 and Air Force MURI grant F49620-01-0359.




AGU Fall Meeting, San Francisco, CA
December 10 - December 14, 2001



Introduction of the CSSS Magnetic Field Model into
the UCSD Tomographic Solar Wind Model

T. Dunn, B.V. Jackson, P.P. Hick, A. Buffington (UCSD/CASS)

Our time-dependent tomographic technique developed over the last few years provides a kinematic model of the solar wind The model, which has one-day time steps, allows us to determine the large-scale three dimensional extents of solar disturbances and to forecast their arrival at Earth in real-time.

We introduce magnetic field predictions from the Stanford Current-Sheet Source Surface model (Zhao and Hoeksema, 1995) at the source surface of our kinematic model and extrapolate the magnetic field out beyond Earth. We show an animated version of the convected magnetic field, and compare results with in situ data near Earth.

Reference: Zhao, X. and J.T. Hoeksema, "Prediction of the interplanetary magnetic field strength", J. Geophys. Res. 100, 19-33, 1995.




Space Weather Using Remote Sensing Data
B.V. Jackson, P.P. Hick, A. Buffington, T. Dunn, S. Rappoport (UCSD/CASS)
M. Kojima, M. Tokumaru, K. Fujiki (STELab, Univ. of Nagoya, Japan)

We are developing tomographic techniques for analyzing remote sensing observations of heliospheric density and velocity structure as observed in Thomson scattering (e.g. using the Helios photometer data) for eventual use with Solar Mass Ejection Imager (SMEI) observations.

We have refined the tomography program to enable us to analyze time-dependent phenomena, such as the evolution of corotating heliospheric structures and more discrete events such as coronal mass ejections. Both types of phenomena are discerned in our data, and are reconstructed in three dimensions. We use our tomography technique to study the interaction of these phenomena as they move outward from the Sun for several events that have been studied by multiple spacecraft in-situ observations and other techniques.

This work is supported by NASA grant NAG5-8504 and AFOSR grant F49620-01-1-0054.




Volume Rendering of Heliospheric Data
P.P. Hick, B.V. Jackson, A. Buffington (UCSD/CASS)
M.J. Bailey (UCSD/SDSC)

We demonstrate some of the techniques we currently use for the visualization of heliospheric volume data. Our 3D volume data usually are derived from tomographic reconstructions of the solar wind density and velocity from remote sensing observations (e.g., Thomson scattering and interplanetary scintillation observations). We show examples of hardware-based volume rendering using the Volume Pro PCI board (from TeraRecon, Inc.). This board updates the display at a rate of up to 30 frames per second using a parallel projection algorithm, allowing the manipulation of volume data in real-time. In addition, the manipulation of 4D volume data (the 4th dimension usually representing time) enables the visualization in real-time of an evolving (time-dependent) data set. We also show examples of perspective projections using IDL. This work was supported through NASA grant NAG5-9423.




Study of ICME Structure Using LASCO White Light and
STE Lab IPS Observations of Halo CMEs

Webb, D.F. (ISR, Boston College)
Tokumaru, M. (STELab, Toyokawa, Japan)
Jackson, B.V., Hick, P.P. (UCSD/CASS)

As part of a long-term investigation of halo-like coronal mass ejections (CMEs) well observed in white light by the SOHO LASCO coronagraphs, we report on a study comparing our catalog of parameters and solar and solar wind associations of halo CMEs with interplanetary disturbances observed with the interplanetary scintillation (IPS) radio array of STE Lab in Japan. We have cataloged over 100 full halo CMEs observed by LASCO from 1996 through 2000. This period covers the first half of solar cycle 23 from activity minimum to maximum. Although the STE Lab observations are limited during each year, nearly all of these CMEs occurring during STE Lab observations were associated with IPS disturbances within a day or so following the halo CME onset time. We will present a summary of these comparisons, and will discuss how the combined data sets can be used to determine key parameters of the 3D shape, structure and propagation of ICMEs. At STE Lab a program is used to find best-fit parameters automatically by matching model calculations to the observed IPS g-value (proportional to plasma density) data. At UCSD a tomographic program is used to reconstruct 3D views of ICMEs using the IPS data in a reconstruction technique based on solar rotation and outward solar wind motion. This work is also pertinent for observations that will be available from the Solar Mass Ejection Imager (SMEI) experiment to be launched next year and, later, from the NASA STEREO mission.




AGU Spring Meeting, Boston, MA
May 29 - June 2, 2001



Certifying Stray-Light Rejection and Photometric
Performance for "SMEI"

A. Buffington, B.V. Jackson, P.P. Hick (UCSD/CASS)

The Solar Mass Ejection Imager (SMEI) is a collaborative project between the Air Force, UCSD/CASS, and the University of Birmingham, England. It will fly on the CORIOLIS spacecraft, scheduled for launch in September 2002. The platform provides a zenith-pointing, terminator orbit. SMEI's three CCD cameras, each viewing a 3°×60° swath of sky, will provide a visible-light map of nearly the entire sky each 100-minute orbit. The instrument is designed to deliver 0.1% differential photometry, and 10−15 scattered-light reduction whe viewing further than 20° from the Sun. We present the results of laboratory measurements which certify that these specifications are met by the SMEI flight hardware. We will also present night-sky data taken with the SMEI prototype optics, and progress on normalizing, flat-field correcting, and registering the SMEI data into a standard sky coordinate frame.
This work is supported by AFRL contract F19628-00-C-0029.




Space Weather Using Remote Sensing Data
B.V. Jackson, P.P. Hick, A. Buffington (UCSD/CASS)

We are developing tomographic techniques for analyzing remote sensing observations of the coronal and heliospheric density and velocity structure as observed in Thomson scattering (e.g. by the SOHO/LASCO coronagraph and Helios photometers) and interplanetary scintillation (IPS) observations.

We have refined the program to enable us to analyze time-dependent phenomena, such as the evolution of co-rotating heliospheric structures and rapidly evolving events such as coronal mass ejections, as observed e.g. with the future Solar Mass Ejection Imager (SMEI) experiment. We currently provide the three-dimensional analyses in real-time using IPS observations in order to forecast the arrival of CMEs and we intend to show these analyses at our display.

This work is supported by NASA grant NAG5-9423 and NSF grant ATM-9819947.




Visualization of Remotely-Sensed Heliospheric Plasmas
P.P. Hick, B.V. Jackson,A. Buffington (UCSD/CASS)
M.J. Bailey (UCSD/SDSC)

We are currently developing a tomographic approach for analyzing remote sensing observations of the coronal and heliospheric density and velocity structure (e.g. Thomson scattering and interplanetary scintillation observations). Parallel to the tomographic techniques we are developing the visualization tools required for displaying and manipulating the three-dimensional tomographic results. We use a common graphics interface language (OpenGL, supported through IDL), standard visual interfaces (pop-up menus, sliders, point-and-click methods) and standard hardware (PCs). The visualization should be capable of simultaneously displaying the tomographic density and velocity model and should allow the user to dynamically view the heliospheric model using any predefined flight path through the three-dimensional cube covered by the model. For real-time volume rendering we use a Mitsubishi Volume Pro PCI board. We present our current progress in this visualization effort. Further details can be found on http://casswww.ucsd.edu/solar/index.html.
This work was supported through NASA grant NAG5-9423.




Solar Encounter: The First Solar Orbiter Workshop
May 14 - 18, 2001, Santa Cruz de Tenerife, Spain



A Heliospheric Imager for Solar Orbiter
B.V. Jackson, A. Buffington, P.P. Hick (UCSD/CASS)

We have developed a prototype instrument for use on a near-Sun, three-axis stabilized, solar-oriented platform such as Solar Orbiter. The imager we envision analyzes remotely-sensed observations of coronal and heliospheric brightness in order to provide context for in-situ plasma measurements. With this sensitive instrument, the analysis of these data will proceed much as it has from our recent use of Thomson-scattering observations from the Helios spacecraft together with a recently developed time-dependent tomographic technique for analyzing these observations.

We show a working model of our heliospheric imager for use on Solar Orbiter, scaled-down from the size required at 1 AU. We also show our most recent tomographic result with Helios photometer data that depicts CMEs as well as corotating structures in the heliosphere and gives correlations of these data with in-situ plasma density measurements at the spacecraft.

This work is supported by NASA grant NAG5-9423.