Wave Activity Associated with Plasmaspheric 1-10 eV Post-Midnight Ion Loss seen by Van Allen Probes
Tuesday, September 29, 2015
Lois K Sarno-Smith1, Michael Warren Liemohn2, Ruth M Skoug3, Aaron W Breneman4, Steven Morley5, Brian Larsen6, Reeves Geoffrey5, John R Wygant7, Craig Kletzing8, Mark Moldwin1, Roxanne M Katus1 and Shasha Zou1, (1)University of Michigan, Ann Arbor, MI, United States, (2)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (3)Los Alamos Natl Lab, Los Alamos, NM, United States, (4)The University of Minnesota, Minneapolis, MN, United States, (5)Los Alamos National Laboratory, Los Alamos, NM, United States, (6)The New Mexico Consortium, Los Alamos, NM, United States, (7)University of Minnesota Twin Cities, Minneapolis, MN, United States, (8)University of Iowa, Iowa City, IA, United States
Abstract:
Following our discovery of post-midnight 1-10 eV plasmaspheric ion loss between L = 2 and L =3, we examine the possibility that the observed ion loss is related to changes in wave activity. Using measurements from the Van Allen Probes Helium, Oxygen, Proton, and Electron (HOPE) and the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instruments, we observe that changes in specific EMFISIS frequency bands are correlated with changes in HOPE H+ thermal ion measurements. In particular, we present results showing variations in cyclotron heating and whistler wave activity as a function of MLT, and their association with low energy plasma distributions. We also discuss how varying levels of geomagnetic activity affect post-midnight thermal ion loss, in particular how this plasmaspheric population responds to changes in the AE index.
