SM32A-07
Trapped Ring Current Ion Dynamics During the 17-18 March 2015 Geomagnetic Storm Obtained from TWINS ENA Images
Wednesday, 16 December 2015: 11:50
2018 (Moscone West)
Joseph D Perez1, Jerry Goldstein2, David J McComas2, Philip W Valek3, Mei-Ching Hannah Fok4 and Kyoung-Joo Hwang4, (1)Auburn University at Montgomery, Auburn, AL, United States, (2)Southwest Research Institute, San Antonio, TX, United States, (3)Southwest Research Inst, San Antonio, TX, United States, (4)NASA Goddard Space Flight Center, Greenbelt, MD, United States
Abstract:
On 17-18 March 2015, there was a large (minimum SYM/H < -200 nT) geomagnetic storm. The Two Wide-Angle Imaging Neutral Atom Spectrometers (TWINS) mission, the first stereoscopic ENA magnetospheric imager, provides global images of the inner magnetosphere from which global distributions of ion flux, energy spectra, and pitch angle distributions are obtained. We will show how the observed ion pressure correlates with SYM/H. Examples of multiple peaks in the ion spatial distribution which may be due to multiple injections and/or energy and pitch angle dependent drift will be illustrated. Energy spectra will be shown to be non-Maxwellian, frequently having two peaks, one in the 10 keV range and another near 40 keV. Pitch angle distributions will be shown to have generally perpendicular anisotropy and that this can be time, space and energy dependent. The results are consistent with Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model simulations.
