Quasi-static model of outer zone electrons

With the Combined Release and Radiation Effects Satellite (CRRES) measurements, an extremely variable outer zone relativistic electron population from 25 July 1990 to 12 October 1991 was observed. Previously, this population has been modeled by the static NASA solar minimum and maximum models. To address the inadequacies of using a static model to describe this highly dynamic environment, the authors develop a quasi-static model of the outer zone electrons based on the Ap geomagnetic activity index. It is shown that certain quantities used to parameterize the electron belt morphology are moderately correlated with the logarithm of the 15-day running average of Ap (Ap₁₅). The authors therefore separate and average, as a function of Ap₁₅, the 438 daily average radiation belt profiles (electron flux versus L) for each of nine energy channels (1-8 MeV). The result is a set of average flux profiles which are keyed to geomagnetic activity. This quasi-static model provides a more accurate representation of the dynamic outer zone electron environment than could be expected from any static model