HR: 0800h
AN: SM31B-1225    [Abstracts]
TI: Ring Current Composition During Sawtooth Storms
AU: * Jahn, J
EM: jjahn@swri.edu
AF: Southwest Research Institute, Space Science Department 6220 Culebra Road, San Antonio, TX 78238-5166 United States
AU: Perez, J D
AF: Auburn University, Physics Department, Auburn, AL 36849 United States
AU: Brandt, P C
AF: Johns Hopkins University/Applied Physics Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 United States
AU: Mitchell, D G
AF: Johns Hopkins University/Applied Physics Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 United States
AU: Henderson, M G
AF: Los Alamos National Laboratory, Group ISR-1, MS D466, Los Alamos, NM 87545 United States
AU: Pollock, C J
AF: Southwest Research Institute, Space Science Department 6220 Culebra Road, San Antonio, TX 78238-5166 United States
AB: Recent IMAGE observations have shown that the gradual development of the hydrogen ring current during sawtooth storms is accompanied by a bursty occurrence of oxygen. The observed oxygen energetic neutral atom (ENA) fluxes are as high, if not sometimes higher, than oxygen fluxes associated with non-sawtooth storms. They appear predominantly during individual sawtooth injections. Once a sawtooth injection has occurred, oxygen ENA fluxes quickly abate due to a combination of precipitation, drift loss and charge exchange. We use ENA inversion techniques to estimate the amount of hydrogen and oxygen plasma in the inner magnetosphere during sawtooth events. Due to the orbit of IMAGE we can monitor the plasma content for 70-80 percent of the time, split into uninterrupted stretches of up to 10 hours apiece. This coverage allows us not only to study the time development of the ring current and the oxygen content during a storm, but to also study several consecutive "teeth" without interruption. We present results from several sawtooth storms that occurred since the fall of 2001. We show the time development of the ring current during those storms, and contrast it with the time history of observed oxygen. For comparison, we will also show data from non-sawtooth storms since 2001.
DE: 2716 Energetic particles, precipitating
DE: 2720 Energetic particles, trapped
DE: 2730 Magnetosphere--inner
DE: 2778 Ring current
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting