Anderson B R, Millan R M, Reeves G D, Friedel R H W
Department of Physics and Astronomy Dartmouth College Hanover New Hampshire USA.
Space Science and Applications Los Alamos National Laboratory Los Alamos New Mexico USA; New Mexico Consortium Los Alamos New Mexico USA.
Geophys Res Lett. 2015 Dec 16;42(23):10113-10119. doi: 10.1002/2015GL066376. Epub 2015 Dec 2.
Past studies of radiation belt relativistic electrons have favored active storm time periods, while the effects of small geomagnetic storms ( > -50 nT) have not been statistically characterized. In this timely study, given the current weak solar cycle, we identify 342 small storms from 1989 through 2000 and quantify the corresponding change in relativistic electron flux at geosynchronous orbit. Surprisingly, small storms can be equally as effective as large storms at enhancing and depleting fluxes. Slight differences exist, as small storms are 10% less likely to result in flux enhancement and 10% more likely to result in flux depletion than large storms. Nevertheless, it is clear that neither acceleration nor loss mechanisms scale with storm drivers as would be expected. Small geomagnetic storms play a significant role in radiation belt relativistic electron dynamics and provide opportunities to gain new insights into the complex balance of acceleration and loss processes.
过去对辐射带相对论电子的研究主要集中在活跃的风暴时期，而小地磁风暴（>-50 nT）的影响尚未得到统计学上的描述。在这项及时开展的研究中，鉴于当前太阳活动周期较弱，我们识别出了1989年至2000年期间的342次小风暴，并对地球同步轨道上相对论电子通量的相应变化进行了量化。令人惊讶的是，小风暴在增强和减少通量方面与大风暴同样有效。虽然存在细微差异，即小风暴导致通量增强的可能性比大风暴低10%，导致通量减少的可能性比大风暴高10%。然而，很明显，无论是加速机制还是损失机制都不像预期的那样与风暴驱动因素成比例。小地磁风暴在辐射带相对论电子动力学中起着重要作用，并为深入了解加速和损失过程的复杂平衡提供了新的契机。
