Responses of equatorial anomaly to the October-November 2003 superstorms
Responses of equatorial anomaly to the October-November 2003 superstorms
复制标题
DOI：
10.5194/angeo-23-693-2005
复制
发表时间：
2005-03
影响因子：
1.9
通讯作者：
B. Zhao;W. Wan;Libo Liu
中科院分区：
文献类型：
--
作者：
B. Zhao;W. Wan;Libo Liu
利用全球定位系统（GPS）观测的中国、东南亚、澳大利亚和美洲地区的总电子含量（TEC）资料，研究了赤道电离异常（EIA）对2003年10 - 11月超级风暴的响应。EIA的增强与行星际磁场B的南转有关。在CSAA和美洲地区，EIA都增强了，对应于中纬度和赤道地区电离层和数字探空仪测量的F层峰值高度（hmF 2）的大幅度增加。而在美洲地区，当B稳定南下时，增强的EIA在白天表现得更为显著，这与一系列大的亚暴有关。根据目前的理论，瞬时穿透电场和风扰动发电机电场被认为是造成这种观测的原因，尽管有些特征不能完全解释。电离图和磁力计数据都表明存在弱屏蔽效应，其效应仍需进一步研究。在我们的TEC观测中，尽管秋分后只有一个月，但电离层的响应却表现出明显的非对称性。10月29日和30日，CSAA地区和美洲地区的EIA南部波峰完全消失。来自国防气象卫星计划（DMSP）航天器的离子温度显示，极区的不均匀能量注入可能是造成这种效应的原因。得出的结论是，不同的物理过程有不同程度的重要性，在CSAA和美洲地区的EIA的演变。
The responses of Equatorial Ionization Anomaly (EIA) to the superstorms of October- November 2003 were investigated using the total electron content (TEC) measured with global positioning system (GPS) receivers in China, Southeast Asia, Australian (CSAA), and the American regions. Enhanced EIA was seen to be correlated with the southward turning of the interplanetary magnetic field B, In both the CSAA and American regions, EIA was intensified, corresponding to a large increase in the F-layer peak height (hmF2) measured by ionosonde and digisonde at middle and equatorial latitudes. However, the enhanced EIA was shown to be more significant during the daytime in the American region, which was associated with a series of large substorms when B, was stable southward. The prompt penetration electric field and the wind disturbances dynamo electric field are suggested to be responsible for this observation according to current theory, although some features cannot be totally decipherable. Both the ionogram and magnetometer data show the existence of a weak shielding effect whose effect still needs further study. A clear asymmetric ionospheric response was shown in our TEC observations, even though it was only one month after autumnal equinox. The southern EIA crest was totally obliterated on 29 and 30 October in the CSAA region and on 31 October in the American region. Ion temperatures from the Defense Meteorological Satellite Program (DMSP) spacecraft revealed that the unequal energy injection at the polar region might be the reason for this effect. It is concluded that different physical processes have varying degrees of importance on the evolution of EIA in the CSAA and American regions.