Timing of Increasing Electron Counts from Geosynchronous Orbit to Low Earth Orbit

ISBN: 1286862841

Author: Olson, Kirk M

Condition: New

Under certain conditions, high energy electron fluxes can increase over short periods of time in the outer radiation belt and diffuse to low altitudes. Sudden increases of high energy electron densities at low altitudes can drastically damage unsuspecting low-earth-orbit satellites. The progression of electron flux increases from a geosynchronous orbit to low-earth orbit during an electron event is somewhat unknown. If the beginning of electron flux increases at low-earth-orbits could be anticipated, warnings could be issued to space system operators allowing time to take proper measures to protect and minimize satellite damage extending satellite lifetimes and space mission operations. The Compact Environment Anomaly Sensors (CEASE) onboard the DSP-21 and TSX-5 satellites collected dosimeter data of electrons gt; 1.2 MeV and protons gt; 25 MeV. The orbits of the satellites and the particle detection of CEASE provided an opportunity to sample the high energy electron population fluxes at GEO and LEO during electron events. The high energy electron CEASE data was extracted from DSP-21 and TSX-5 when each satellite crossed an approximate geosynchronous L-Shell range (L=6.5-6.7). Onsets of electron events at each orbit were determined from the data. Onset comparison showed the progression of elevated electron fluxes from GEO to LEO to be between one and four days. Further comparison of the electron events to solar wind data suggests that high speed streams are necessary, not sufficient, for an electron event to occur.