Multiple ground-based observations at Zhongshan Station during the April/May 1998 solar events  

作　　者：刘瑞源 胡红桥 贺龙松 刘勇华 刘顺林 李胜桂 N. Sato B. J. Fraser 

机构地区：[1]Polar Research Institute of China, Shanghai 200129, China Department of Radio Science and Technology, Wuhan University, Wuhan 430072, China [2]Polar Research Institute of China, Shanghai 200129, China [3]National Institute of Polar Research, Tokyo 173, Japan [4]Department of Physics, University of Newcastle, Australia

出　　处：《Science China Mathematics》2002年第z1期120-131,共12页中国科学：数学（英文版）

基　　金：the National Natural Science Foundation of China (Grant Nos. 49634160, 40074038) ; the Major Scientific Project of the Chinese Academy of Sciences (655951-1-305).

摘　　要：Simultaneous observations at Zhongshan Station, Antarctica, during May 1-7, 1998 are presented to show the responses of the polar ionosphere to the April/May 1998 solar events. One of the main geo-effects of the solar events resulted in the major magnetic storm on May 4. At the storm onset on May 2 the ionosphere F2 layer abruptly increased in altitude, the geomagnetic H-component started negative deviation and the spectral amplitude of the ULF wave intensified. Both large isolated riometer absorption and large negative deviation of the geomagnetic H-component occurred at about 0639UT. There was a time lag of about one hour and ten minutes between the storm onset and the IMF southward turning, as measured by the WIND satellite. The polar ionosphere was highly disturbed, as shown by frequent large deviations of the geomagnetic H-component, large riometer absorption events and strong ULF waves in all the courses of the storm. The absorption increased greatly causing the digisonde to be blackout most of the time. However, the data still showed a substantial decrease in the F2 electron density and oscillation of the F2 layer peak height with an amplitude exceeding 200 km.Simultaneous observations at Zhongshan Station, Antarctica, during May 1-7, 1998 are presented to show the responses of the polar ionosphere to the April/May 1998 solar events. One of the main geo-effects of the solar events resulted in the major magnetic storm on May 4. At the storm onset on May 2 the ionosphere F2 layer abruptly increased in altitude, the geomagnetic H-component started negative deviation and the spectral amplitude of the ULF wave intensified. Both large isolated riometer absorption and large negative deviation of the geomagnetic H-component occurred at about 0639UT. There was a time lag of about one hour and ten minutes between the storm onset and the IMF southward turning, as measured by the WIND satellite. The polar ionosphere was highly disturbed, as shown by frequent large deviations of the geomagnetic H-component, large riometer absorption events and strong ULF waves in all the courses of the storm. The absorption increased greatly causing the digisonde to be blackout most of the time. However, the data still showed a substantial decrease in the F2 electron density and oscillation of the F2 layer peak height with an amplitude exceeding 200 km.

关 键 词：polar ionosphere magnetic storm cosmic noise adsorption ULF wave solar activity CME. 

分 类 号：P182[天文地球—天文学]