SM41E-2545
The plasmasheet H+ and O+ contribution on the storm time ring current
Thursday, 17 December 2015
Poster Hall (Moscone South)
Christopher Mouikis1, Sam Bingham1, Lynn M Kistler1, Harlan E. Spence2, Matina Gkioulidou3, Seth G Claudepierre4 and Charles J Farrugia1, (1)University of New Hampshire Main Campus, Durham, NH, United States, (2)University of New Hampshire Main Campus, Space Science Center, Durham, NH, United States, (3)Applied Physics Laboratory Johns Hopkins, Laurel, MD, United States, (4)Aerospace Corporation Santa Monica, Santa Monica, CA, United States
Abstract:
The source population of the storm time ring current is the night side plasma sheet. We use Van Allen Probes and Cluster observations to determine the contribution of the convecting plasma sheet H+ and O+ particles in the storm time development of the ring current. Using the Volland-Stern model with a dipole magnetic field together with the identification of the observed energy cutoffs in the particle spectra, we specify the pressure contributed by H+ and O+ populations that are on open drift paths vs. the pressure contributed by the trapped populations, for different local times. We find that during the storm main phase most of the ring current pressure in the pre-midnight inner magnetosphere is contributed by particles on open drift paths that cause the development of a strong partial ring current that causes most of the main phase Dst drop. These particles can reach as deep as L~2 and their pressure compares to the local magnetic field pressure as deep as L~3. During the recovery phase, if these particles are not lost at the magnetopause, will become trapped and will contribute to the symmetric ring current.
