中国地区地磁静日变化场S_q(H)台链分布特征

Research on the Distribution of Geomagnetic Daily Variation along Some Station Chains in China

选取地磁台网数字化观测资料,分析了中国地区Sq(H)的时空分布特征,得出以下结论:(1)经度链Sq(H)在夏季和春秋季存在明显的午前午后不对称现象;(2)夏、春秋、冬3个时段Sq焦点的平均位置分别大约为27°N、29°N和35°N。这只是一个平均状态,单个静日的Sq焦点有可能出现在50°N以北,也可能出现在19°N以南;(3)两条经度链上H变幅的纬向变化趋势不一致现象、相同纬度链上Sq(H)形态反向或者H变幅自东向西递增(减)现象,均说明Sq焦点在自东向西的迁移过程中,除了经向上的迁移外,还有纬向上的迁移或者电流强度的变化。

The temporal and spatial distribution of Sq（H）in China was analyzed based on the geomagnetic digitized data from the geomagnetic observation network.It was found that：（1）there was obvious prenoon-postnoon asymmetry of Sq（H）in Summer and Equinox.（2）in Summer,Equinox and Winter,the averaged focus position of Sq were 27 ° N,29 ° N and 35 ° N respectively.But in a single quiet day,the focus of Sq might appear in the north of 50 ° N and in the south of 19 ° N.（3）there were some special behavior of the Sq（H）distributions such as the latitudinal trend inconsistencies in two longitudinal chain,the reverse of Sq（H）variations in the same latitudinal chain and the increase（decrease）of the daily ranges from east to west.All these demonstrated that there might be latitudinal migration of the Sq focus or changes in current intensity during the longitudinal migration of Sq focus from east to west.