Observations of exosphere variations during geomagnetic storms
Observations of exosphere variations during geomagnetic storms
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DOI：
10.1002/grl.50443
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发表时间：
2013-05-28
影响因子：
5.2
通讯作者：
Gruntman, M.
中科院分区：
文献类型：
--
作者：
Bailey, J.;Gruntman, M.
地球上层外逸层的主要中性成分氢原子（H）共振散射太阳莱曼α（121.567 nm）辐射，被观测为地日冕。我们在这里报告的观测外大气层对地磁暴的反应，获得使用测量的地冠莱曼α探测器的两个广角成像中性原子光谱仪使命。我们引入了一个新的参数，N-H，在球壳中的H原子的数量从3到8个地球半径的地心距离，以定量表征在一个简化的方式全球外逸层的条件。在2011年下半年的三个月里观测到的五次磁暴伴随着N-H从6%到17%的突然暂时增加，峰值，持续时间不超过一天。这些增加似乎显示出与每次风暴高峰期间达到的最小Dst指数有一定的相关性。
The dominant neutral constituent in Earth's upper exosphere, atomic hydrogen (H), resonantly scatters solar Lyman-alpha (121.567nm) radiation, observed as the geocorona. We report here observations of an exospheric response to geomagnetic storms obtained using measurements of the geocorona by Lyman-alpha detectors on the Two Wide-angle Imaging Neutral-atom Spectrometers mission. We introduce a new parameter, N-H, the number of H atoms in the spherical shell from a geocentric distance of 3 to 8 Earth radii, to quantitatively characterize in a simplified way global exospheric conditions. Five geomagnetic storms observed during three months in the second half of 2011 are accompanied by abrupt temporary increases, spikes, of N-H from 6% to 17%, lasting not longer than a day. These increases seem to show some correlation with the minimum Dst index reached during the peak of each storm.