电离层电场对环电流变化响应的时延

本文讨论了强磁暴期间磁层环电流能量变化率与电离层电场变化之间的联系.STARE和SABRE雷达资料表明,电离层对环电流变化响应的主要特点是:(1)在磁地方时午后区,响应的时延达最大(约1—2小时),场强以指数形式增加;在其它时区内,无系统的增强过程,仅观测到较大的、有明显涨落的电场值.(2)STARE(70.2°N)和SABRE(65.8°N)测到的电场变化往往具有相反的趋势.(3)在STARE视场内,环电流能量变化达极大后,较低纬(70.2°N)上的电场值经常大于较高纬(71.8°N)上的值.分析结果表明,磁暴期间磁层-电离层耦合过程中,环电流起着重要作用. 

The Time Delay of the Ionospheric Response to the Ring Current Variation

The link between intensification of the ring current inflation rate and the variation of ionospheric electric fields during the long-lasted storms is discussed. The main features of the ionospheric response to the ring current variation observed by STAREand SABREare the following: (1) The ionospheric response has a time delay of 1-2 hours in the afternoon sector of MLTwhere the electric field increases as a near-exponentiasl function, while in other sectors there is no delay and no systematic increase of electric fields, but an enhanced state with fluctuations, can be found. (2) Opposite tendency of electric field variations often appears from STARE (70.2°N) and SABRE (65.8°N) observations. (3) In the STAREfield of view the magnitude of electric fields at lower latitude (70.2°N) is usually larger than that at higher latitude (71.8°N) during ring current increase events. These facts are consistent qualitatively with predictions of simple model of Zi and Shen, 1986. The results show that the ring current has an important influence on the magnetosphere-ionosphere coupling.