摘要
为研究2010年4月地球同步轨道相对论电子通量异常增强事件的原因,选取了2004—2010年之间高速太阳风下7个类似事件进行对比分析.探讨了多种可能导致此次异常事件的太阳风和地磁条件.结果表明,较弱的磁暴使得相对论电子高通量区域更接近同步轨道,此外,哨声波加速很可能在2010年4月地球同步轨道相对论电子通量异常增强事件中起到重要作用.磁暴强度与种子电子的注入深度密切相关,表现为Dst指数曲线的形态与能量为30～100 keV的电子高通量区域的下边缘高度吻合.能量为30～100 keV电子的注入深度影响了能量大于300keV的电子出现的磁层区域.此事件中,由于磁暴相对较弱,种子电子向内磁层注入的深度较浅,更靠近同步轨道区域,这使得相对论电子大量出现的区域也靠近同步轨道,最终导致同步轨道相对论电子通量异常增强.另外,2010年4月地球同步轨道相对论电子通量异常增强事件中,高强度的亚暴提供了充足的种子电子并加强了波粒相互作用,这也是相对论电子增强的必要条件.
The relativistic electron flux enhancement event at GEO in April 2010 is analyzed in contrasting with other 6 similar events from 2004 to 2010. Solar wind and geomagnetic conditionswhich might trigger this event were analyzed. Analytical results indicate that the relatively weaker magnetic storms were prone to make the high flux part of relativistic electrons closer to GEO orbit, and whistler wave acceleration mechanism probably played important roles. The injection depth of seed electrons was closely related to magnetic storm intensity. Dst index curve is well fitted with the lower edge of higher flux region of 30-100keV electrons. The injection depth of seed electrons determined the region where mass of 〉 300 keV electrons appeared. Because of the relatively weak storms in the relativistic electron flux enhancement event, the seed electrons injected into a shallow region which was close to geosynchronous orbit, leading to relativistic electron flux abnormally enhancement in geosynchronous orbit. The intense substorms in relativistic electron flux enhancement event at GEO in April 2010, which generated sufficient seed electrons and enhanced the wave-particle interaction, was an essential factor leading to relativistic electrons flux enhancement.
出处
《空间科学学报》
CAS
CSCD
北大核心
2012年第4期488-500,共13页
Chinese Journal of Space Science
基金
国家重点基础研究发展计划项目资助(2011CB811400)
关键词
相对论电子
地球同步轨道
磁暴
亚暴
DST指数
Relativistic electrons, Geosynchronous orbit, Magnetic storm, Magnetic substorm,Dst index
