HR: 1330h
AN: SM32B-1153    [PDF]
TI: ENA Images of Ring Current Ion Precipitation 14-24 April 2002
AU: * DeMajistre, R
EM: robert.demajistre@jhuapl.edu
AF: The Johns Hopkins University Applied Physcis Laboratory, 11100 JOHNS HOPKINS RD, LAUREL, MD 20723-6099 United States
AU: Roelof, E C
EM: ed.roelof@jhuapl.edu
AF: The Johns Hopkins University Applied Physcis Laboratory, 11100 JOHNS HOPKINS RD, LAUREL, MD 20723-6099 United States
AU: C:son Brandt, P
EM: Pontus.brandt@jhuapl.edu
AF: The Johns Hopkins University Applied Physcis Laboratory, 11100 JOHNS HOPKINS RD, LAUREL, MD 20723-6099 United States
AU: Mitchell, D G
AF: The Johns Hopkins University Applied Physcis Laboratory, 11100 JOHNS HOPKINS RD, LAUREL, MD 20723-6099 United States
AB: The High Energy Neutral Atom (HENA) camera on the IMAGE spacecraft images ion precipitation from the ring current through the upward ENA albedo of the downward ion precipitation. A newly developed ion/neutral transport theory predicts that an appreciable fraction of the incident ions will emerge from the exosphere (albeit at a lower energy due to inelastic collisions). These emerging intensities register dramatically in the HENA images during perigee passes, yielding about 6 images with excellent pixel statistics in each 2-minute exposure. The viewing aspect during the STORMS2002 period (14-24 April) was excellent at approximately 1500 km altitude over the southern polar cap. Almost the entire sub-auroral precipitation region falls within the images at some time during the passes. The emission from precipitation is also imaged at higher altitudes when IMAGE is between about N40$^\circ$-N60$^\circ$ magnetic latitude, but at greatly reduced spatail resolution at the larger radial distances of 4-7 R$_E$. Our analysis techniques are still in the early stages of development, but even so, the ENA images can indicate when and where ring current precipitation is occurring. Thus they promise a new measure of geo-effectiveness of magnetic storm activity.
DE: 2716 Energetic particles, precipitating
DE: 2720 Energetic particles, trapped
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2788 Storms and substorms
DE: 2794 Instruments and techniques
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting