Differentiating Loss Mechanisms of Outer Radiation Belt Relativistic Electrons from Multisatellite Observations
Abstract
The harsh environment of relativistic electrons (E>.511MeV) has an obvious impact on space weather. Therefore understanding the physical processes controlling relativistic electron dynamics—acceleration, loss and transport—in the Earth's outer radiation belt is the prerequisite for development of space weather forecast models. Comparing to the progresses that have been made on acceleration and transport processes, loss processes are much less understood and characterized. Analyzing in-situ observations, especially long-term and/or simultaneous observations from multisatellite observations, is a powerful approach to differentiate two competitive loss mechanisms: precipitation and the outward diffusion associated with magnetopause shadowing. We will perform case and statistical studies of electron observations from two groups of satellites: One includes GPS, LANL GEO, Polar, and SCATHA that measure the trapped electron population at different L-shells from high altitude; the other is SAMPEX and NOAA POES that measure near-loss-cone electrons from low altitude from several local time positions. First we will develop an empirical model that describes the precipitation as functions of electron energy, longitude, latitude/L-shell, local time, season, storm phase and solar-cycle phase. Then by comparing the decay rate of trapped electrons observed at the equatorial plane to the precipitation rates observed at low altitude, we can quantitatively determine the role of precipitation on the loss of relativistic electrons, especially for the portion of radiation belt with L>4, during the main phase of storms.
- Publication:
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37th COSPAR Scientific Assembly
- Pub Date:
- 2008
- Bibcode:
- 2008cosp...37..510C