Sun-Earth connection event of super geomagnetic storm on 2001 March 31:the importance of solar wind density  

作　　者：Li-Bin Cheng Gui-Ming Le Ming-Xian Zhao 

机构地区：[1]School of Physics and Electronic Information,Shangrao Normal University,Shangrao 334001,China [2]National Center for Space Weather,China Meteorological Administration,Beijing 100081,China

出　　处：《Research in Astronomy and Astrophysics》2020年第3期122-128,共7页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41074132,41274193 and41474166).

摘　　要：An X1.7 flare at 10:15 UT and a halo CME with a projected speed of 942 km s-1 erupted from NOAA solar active region 9393 located at N20 W19,which were observed on 2001 March 29.When the CME reached the Earth,it triggered a super geomagnetic storm(hereafter super storm).We find that the CME always moved towards the Earth according to the intensity-time profiles of protons with different energies.The solar wind parameters responsible for the main phase of the super storm occurred on 2001 March 31 are analyzed while taking into account the delayed geomagnetic effect of solar wind at the L1 point and using the SYM-H index.According to the variation properties of SYM-H index during the main phase of the super storm,the main phase of the super storm is divided into two parts.A comparative study of solar wind parameters responsible for two parts shows the evidence that the solar wind density plays a significant role in transferring solar wind energy into the magnetosphere,besides the southward magnetic field and solar wind speed.An X1.7 flare at 10:15 UT and a halo CME with a projected speed of 942 km s-1 erupted from NOAA solar active region 9393 located at N20 W19, which were observed on 2001 March 29. When the CME reached the Earth, it triggered a super geomagnetic storm（hereafter super storm）. We find that the CME always moved towards the Earth according to the intensity-time profiles of protons with different energies. The solar wind parameters responsible for the main phase of the super storm occurred on 2001 March 31 are analyzed while taking into account the delayed geomagnetic effect of solar wind at the L1 point and using the SYM-H index. According to the variation properties of SYM-H index during the main phase of the super storm, the main phase of the super storm is divided into two parts. A comparative study of solar wind parameters responsible for two parts shows the evidence that the solar wind density plays a significant role in transferring solar wind energy into the magnetosphere, besides the southward magnetic field and solar wind speed.

关 键 词：SUN CORONAL mass ejections(CMEs)-Sun solar-terrestrial relations--Sun solar wind 

分 类 号：P353[天文地球—空间物理学]