X级以上耀斑与地磁效应关系研究

统计研究了2010年1月至2012年12月期间所有与耀斑爆发相伴生的日冕物质抛射(CME) 引发的地磁暴事件. 结果表明, 对于CME源区其主要分布在日面 45°E-45°W, 占总数的78.95%, 且西半球比东半球多, 即源区位于西半球的CME易产生地磁效应; X级耀斑与地磁效应的关联性更高, 60.0%的 X级耀斑在其爆发后的2～3天内观测到地磁暴, 而其他级别的耀斑与地磁效应的关联性低得多, 均不足10%; 通过对此期间日面爆发的所有X级耀斑研究分析后发现, 对于源区位于日面东经45°E-45°W 的X级耀斑, 若在其爆发过程中没有大尺度日面扰动, 则无伴生CME且后续产生地磁效应的可能性很低. 由此提出一种通过分析日面观测数据进行地磁暴预报的方法.

Relationship between X-class Flares and Geomagnetic Effects

A statistical study has been conducted on all the geomagnetic storms caused by Coron Mass Ejection (CMEs) which are associated with flares from January 2010 to December 2012. The following results are obtained. The initial locations of CMEs mentioned above are distributed from 45°E to 45°W in solar longitude, accounting 78.95% of the total. Besides, the CMEs located in the west hemisphere are more likely to cause geomagnetic effects. X-class flares are more likely to be geo-effective, while flares in other classes have much lower probability. Geomagnetic storms will be observed in two or three days after 60% of X-class flares eruption. Therefore, more attention should been paid on X-class flares. By analyzing all the X-class flares erupted during this period, it is found that for the X-class flares located from 45°E to 45°W in solar longitude, if there is no disturbance on the solar surface (EUV wave) during eruption, the probability of the occurrence of geomagnetic storms after the flares will be very small. Therefore, a new method for geomagnetic storm forecasting by analyzing the Sun surface observations has been proposed.