Energization of relativistic electrons in the presence of ULF power and MeV microbursts: Evidence for dual ULF and VLF acceleration
Energization of relativistic electrons in the presence of ULF power and MeV microbursts: Evidence for dual ULF and VLF acceleration
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DOI：
10.1029/2002ja009784
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发表时间：
2003-08-26
影响因子：
2.8
通讯作者：
Anderson, RR
中科院分区：
文献类型：
--
作者：
O'Brien, TP;Lorentzen, KR;Anderson, RR
[1]我们研究了两种类型的波，可能涉及在地球的外辐射带的高能电子的加速签名。我们已经编制了一个数据库的超低频波功率从SAMNET和IMAGE地面磁强计站1987 - 2001年。长时间，全面的，在现场的VLF/ELF合唱波观测是不可用的，所以我们推断合唱波活动的低空SAMPEX观测MeV电子微暴为1996 - 2001年，因为微暴被认为是由合唱和被困电子之间的相互作用。我们比较了ULF和微下击暴流观测到的高空卫星观测到的原位捕获电子从1989年至2001年。我们发现，在低L壳层的电子加速是密切相关的超低频活动和兆电子伏的微暴流，从而也可能与合唱活动。一般来说，穿过外辐射带的电子通量增强与ULF和VLF/ELF活动有关。然而，我们认为，在L类似于4.5观察到的电子通量峰值很可能是由VLF/ELF波加速引起的，而ULF活动可能会在地球同步轨道及更远的地方产生占主导地位的电子加速。
[1] We examine signatures of two types of waves that may be involved in the acceleration of energetic electrons in Earth's outer radiation belts. We have compiled a database of ULF wave power from SAMNET and IMAGE ground magnetometer stations for 1987 - 2001. Long-duration, comprehensive, in situ VLF/ELF chorus wave observations are not available, so we infer chorus wave activity from low-altitude SAMPEX observations of MeV electron microbursts for 1996 - 2001 since microbursts are thought to be caused by interactions between chorus and trapped electrons. We compare the ULF and microburst observations to in situ trapped electrons observed by high-altitude satellites from 1989 - 2001. We find that electron acceleration at low L shells is closely associated with both ULF activity and MeV microbursts and thereby probably also with chorus activity. Electron flux enhancements across the outer radiation belt are, in general, related to both ULF and VLF/ELF activity. However, we suggest that electron flux peaks observed at L similar to 4.5 are likely caused by VLF/ELF wave acceleration, while ULF activity probably produces the dominant electron acceleration at geosynchronous orbit and beyond.