Ion equatorial distributions from ENA images obtained by IMAGE during
geomagnetic storms: Drift of Ion Flux

X. X. Zhang, J. D. Perez
Physics Department, Auburn University,Auburn, AL

M.-C. Fok
NASA Goddard Space Flight Center, Greenbelt, MD

D. G. Mitchell
The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD

C. J. Pollock
Southwest Research Institute, San Antonio, TX

X. Y. Wang, Y. Lin
Physics Department, Auburn University, Auburn, AL


Energetic neutral atom (ENA) images in the energy range of 1 - 60 keV are
being obtained by the medium and high energetic neutral atom (MENA/HENA)
imagers on board the IMAGE satellite. These ENA emissions reveal the ion
distribution and its evolution during geomagnetic storms and/or substorms.
During the development of magnetospheric storms and/or substorms, the ENA
enhancements associated with magnetic field dipolarizations and inward
plasma injections are also observed by geosynchronous LANL satellites
(1989-046, 1990-095, 1991-080, 1994-084, LANL-97A) and GOES (GOES-8 and
GOES-10), and in the proton aurora as observed by the far ultra violet (FUV)
imager on board IMAGE. The ion equatorial pitch angle distributions have
been extracted from the MENA and HENA images for the time periods in June
10, 2000, August 12, 2000 and October 4, 2002. We will show deconvolved
results that illustrate energy-dependent drift patterns and present
comparisons with observations from the geosynchronous satellites and the FUV
imager. Simulations of ion trajectories will be used to interpret features
observed in the trapped ion flux.

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To be presented at the 2002 Spring A.G.U. Meeting, 
Washington, D.C., U.S.A., 28-31 May 2002