SM53A-06
Ion spectral structures observed by the Van Allen Probes
Friday, 18 December 2015: 14:43
2018 (Moscone West)
Cristian Ferradas1, Jichun Zhang2, Harlan E. Spence2, Lynn M Kistler3, Brian Larsen4, Geoffrey D Reeves5, Ruth M Skoug6 and Herbert O Funsten7, (1)University of New Hampshire, Durham, NH, United States, (2)University of New Hampshire Main Campus, Space Science Center, Durham, NH, United States, (3)University of New Hampshire Main Campus, Durham, NH, United States, (4)The New Mexico Consortium, Los Alamos, NM, United States, (5)Los Alamos National Laboratory, Los Alamos, NM, United States, (6)Los Alamos Natl Lab, Los Alamos, NM, United States, (7)Los Alamos Natl Laboratory, Los Alamos, NM, United States
Abstract:
During the last decades several missions have recorded the presence of dynamic spectral features of energetic ions in the inner magnetosphere. Previous studies have reported single “nose-like” structures occurring alone and simultaneous nose-like structures (up to three). These ion structures are named after the characteristic shapes of energy bands or gaps in the energy-time spectrograms of in situ measured ion fluxes. They constitute the observational signatures of ion acceleration, transport, and loss in the global magnetosphere. The HOPE mass spectrometer onboard the Van Allen Probes measures energetic hydrogen, helium, and oxygen ions near the inner edge of the plasma sheet, where these ion structures are observed. We present a statistical study of nose-like structures, using 2-years measurements from the HOPE instrument. The results provide important details about the spatial distribution (dependence on geocentric distance), spectral features of the structures (differences among species), and geomagnetic conditions under which these structures occur.
