MeV electron populations as measured on DMSP

A dosimeter flown on the DMSP F7 spacecraft during solar minimum from January 1984 through October 1987 measured electron fluxes and dose behind four different dome thicknesses. The spacecraft was in an 840-km, circular, polar orbit with a 101-min orbit period. Using sophisticated display and analysis software developed for the CRRES (Combined Release and Radiation Effects Satellite) program, the DMSP database was reexamined. Displays of the data set uncovered previously unseen phenomena including >2.5-MeV electron penetrations to low magnetic latitudes during magnetospheric storm periods. During three periods (1 August 1984, 8-9 February 1986, and 12 September 1986) the >2.5-MeV electrons were measured penetrating all the way to the magnetic equator. The particle penetrations occurred during periods of high magnetic activity as indicated by K_p and other indices