HR: 10:50h
AN: SH22A-03    [Abstracts]
TI: The 3D structure of CMEs from LASCO polarization measurements
AU: * Dere, K P
EM: kdere@gmu.edu
AF: George Mason University, Mail Stop 5C3 4400 Univeristy Drive, Fairfax, VA 22030 United States
AU: Wang, D
EM: dennis.wang@nrl.navy.miml
AF: Interferometrics Inc., Code 7660 Naval Research Laboratory, Washington, DC 20375 United States
AU: Howard, R
EM: russell.howard@nrl.navy.mil
AF: Naval Research Laboratory, Code 7660 4555 Overlook Ave., Washington, DC 20375 United States
AB: The polarization of Compton scattered light from a coronal plasma is a function of the distance of that plasma from the plane of the sky. From an image of the polarization of the corona it is possible to construct a 3D cube of intensity which can be visualized at any angle to study it's three dimensional distribution. For a one month period during July and August 2002, the LASCO C2 coronagraph performed polarization measurements with a one hour cadence. During this period, several CMEs were well observed. Two CMEs give the appearance of an ejecting loop arcade. Another CME is not as easily described but may indicate the presence of a flux tube. There are two main ambiguities in the analysis. First, a given polarization can be produced by scattering from in front of or behind the plane of the sky. This ambiguity can be overcome by selecting CMEs that are completely out of the plane of the sky. Second, in reconstructing the 3D distribution of intensity, it is assumed that the intensity can be visualized as coming from a single point in 3D space. The filamentary structures commonly seen in the 3D visualizations suggest that this is not a significant problem.
DE: 7513 Coronal mass ejections
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting