STORM-TIME JOULE HEATING OF AURORAL THERMOSPHERE AND IONIZATION DEPLETION IN THE F-REGION ──EISCAT RADAR OBSERVATION

With the help of EISCAT radar data, auroral ionospheric electromagnetic parameters, such as convection electric field, conductivity tensor, and Joule heating rates etc. are calculated and analyzed for an intense magnetic storm (min.D_st<=-150nT) occurring in summer of a high solar activity year. An investigationis emphatically made on the relationship between the thermospheric Joule heatingin the E-region and frictional heating of ions in the F-region with the ionizationdepletion in the F-region. It is found that at the sector of eastward auroral electrojet in the afternoon, a maximum depletion of 70% in electron density occurs ataltitudes of 300-325 km, its occurrence lags just 5-10 minutes after the integatedJoule heating reaches to its mamximun of about 92 mW/m² in the E-region and ionfrictional heating in the F-region, to its maximum, too.