暴时极光区热层大气焦耳加热与F区电离耗空的EISCAT雷达观测

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

利用EISCAT雷达探测数据，分析计算了太阳活动高年夏季发生的一次强磁暴（最小Dst=-150nT）期间，极光区电离层对流电场、电导率以及焦耳加热速率等参量．着重考察了E区热层大气焦耳加热和F区离子摩擦增温与F区电子密度耗空的关系．发现在下午东向极光电集流期间，电子密度最大耗空出现在F区300—325km高度，时间恰在积分的E区大气焦耳加热最大值（92mW／m2）和F区最大离子增温之后5—10min，耗空率达70％．

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.Dst=-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.