scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...

STP12 Abstracts
Berlin, 12 - 16 July 2010
SCOSTEP Symposium 2010
Evolution and Energization of Energetic Electrons in the Inner Magnetosphere
Fennell J. 1 , Kanekal S. 2 , Roeder J. 3
1 Aerospace Corp., 2 University of Colorado, 3 Aerospace Corp
We use more than a solar cycle of HEO observations to examine the inner magnetosphere’s
energetic electron response to both geomagnetic storms and extended quieting periods of solar
cycle 23. We follow the penetration and enhancements of the electrons as a function of L
value using HEO1 and HEO3 observations. HEO3 measures electrons of >130, >230, >450,
>630, >1500 and >3000 keV and makes four traversals of the L=2-7 Re region each day.
HEO1 measures electrons >130, >230, >1500, >4000, >6500, and >8500 keV down to L~4
every day and down to L~2.5 during some intervals . We show the relationship between high
altitude and low altitude fluxes on the same L shells and demonstrate that often the High/Low
flux ratios are relatively constant, evidence of a global coherence in the fluxes, irrespective of
absolute flux levels. We find that small to moderate storms often caused enhancements in the
630 keV electron fluxes for L3 MeV at L values
down to 2.5. For such events, the reletivistic electron fluxes peaked in the L~3.75-4.25 range
depending on their energy.
.