Auroral-Enhanced Plasma Lines by Suprathermal Electrons Observed by EISCAT

摘要

Plasma lines (PLs) observed by the European Incoherent Scatter Scientific Association (EISCAT) incoherent scatter radar (ISR) data set during the recent solar maximum 2014 are investigated. To statistically analyze the PLs in the EISCAT data set, we develop an algorithm for the automatic extraction of naturally enhanced PLs from the ISR spectra. Two typical types of auroral-enhanced PLs at high latitude, namely, secondary electron and electron beam, are analyzed based on this PL extraction algorithm. Our results show that PL enhancements originating from secondary electrons and electron beams present evident magnetic local time dependence. Moreover, the statistical study indicates that the PL enhancements are correlated with the geomagnetic and solar activities. These results can provide insights into solar wind-magnetosphere-ionosphere coupling mechanisms.