IPS Tomography Models Halo CME The Solar Physics group at UCSD's Center for Astrophysics and Space Sciences has successfully modeled a massive halo CME in real-time. The CME occurred on July 26, 2002 and was first observed by the LASCO C2 Coronagraph on SOHO, the Solar and Heliospheric Observatory. The structure was then seen in UCSD's tomographic reconstructions of the solar wind which incorporate IPS (interplanetary scintillation) data from Stelab in Japan. In the image on the left, taken by LASCO on July 26, a large mass ejection can be seen near the Sun's south pole. The coronagraph image shows the solar corona with a scale 3 degrees across. The image on the right is a tomographic reconstruction (a CAT scan) of solar wind density. There is a large density enhancement seen moving south of the Earth on July 29. The reconstructions are 60 degrees across and show the Sun, the Earth, and its orbit from an observer located at three times the Sun-Earth distance, 30 degrees above the plane of the Earth's orbit. Click here for .avi movie of July 26 event. The IPS data also show high velocity wind flow (darker blue) around the region of density enhancement, seen below. The synoptic map below from July 29 shows the high density region south of the Earth. Science Contact: Bernard Jackson bvjackson@ucsd.edu (858) 534-3358