The auroral data observed by all sky TV camera during 1995 and 1997 at Zhongshan Station of Antarctica are used to analyze the statistic characteristics of the aurora over Zhongshan Station. Around postnoon (1200 - 16...The auroral data observed by all sky TV camera during 1995 and 1997 at Zhongshan Station of Antarctica are used to analyze the statistic characteristics of the aurora over Zhongshan Station. Around postnoon (1200 - 1600UT ) and midnight (2000 - 0100 UT ), the aurora appears more frequently and stronger than those in evening (1600- 2000UT ). The corona type auroras mainly occur at poleward and overhead of Zhongshan Station during postnoon and around midnight. The hand type auroras mainly appear during postnoon. while during evening and around midnight only appear at equatorward. The active surges mostly appear around midnight,while the transpolar arcs mainly occur after midnight. Except for the transpolar arcs. the occurrences of the other three type auroras are related with Kp index. Usually Zhongshan Station enters the auroral oval at postnoon,the exact time depends on Kp index.展开更多
An unidentified geophysical event is first reported in this paper. It was recorded with Lacoste & Romberg earth tide gravity meter (ET 21) at Chinese Antarctic Zhongshan Station.
The solar wind almost disappeared on May 11,1999: the solar wind plasma density and dynamic pressure were less than 1cm^(-3) and 0.1 nPa respectively, while the interplanetary mag- netic field was northward. The polar...The solar wind almost disappeared on May 11,1999: the solar wind plasma density and dynamic pressure were less than 1cm^(-3) and 0.1 nPa respectively, while the interplanetary mag- netic field was northward. The polar ionospheric data observed by the multi-instruments at Zhong- shan Station in Antarctica on such special event day was compared with those of the control day (May 14). It was shown that geomagnetic activity was very quiet on May 11 at Zhongshan. The magnetic pulsation, which usually occurred at about magnetic noon, did not appear. The iono- sphere was steady and stratified, and the F_2 layer spread very little. The critical frequency of day- side F_2 layer, f_0F_2, was larger than that of control day, and the peak of f_0F_2 appeared 2 hours earlier. The ionospheric drift velocity was less than usual. There were intensive auroral E_s appearing at magnetic noon. All this indicates that the polar ionosphere was extremely quiet and geomagnetic field was much more dipolar on May 11. There were some signatures of auroral substorm before midnight, such as the negative deviation of the geomagnetic H component, accompanied with auroral E_s and weak Pc3 pulsation.展开更多
文摘The auroral data observed by all sky TV camera during 1995 and 1997 at Zhongshan Station of Antarctica are used to analyze the statistic characteristics of the aurora over Zhongshan Station. Around postnoon (1200 - 1600UT ) and midnight (2000 - 0100 UT ), the aurora appears more frequently and stronger than those in evening (1600- 2000UT ). The corona type auroras mainly occur at poleward and overhead of Zhongshan Station during postnoon and around midnight. The hand type auroras mainly appear during postnoon. while during evening and around midnight only appear at equatorward. The active surges mostly appear around midnight,while the transpolar arcs mainly occur after midnight. Except for the transpolar arcs. the occurrences of the other three type auroras are related with Kp index. Usually Zhongshan Station enters the auroral oval at postnoon,the exact time depends on Kp index.
文摘An unidentified geophysical event is first reported in this paper. It was recorded with Lacoste & Romberg earth tide gravity meter (ET 21) at Chinese Antarctic Zhongshan Station.
基金the National Natural Science Foundation of China (Grant Nos. 40104009, 40074038)the Major Scientific Project of Chinese Academy of Sciences (655951-1-305)+1 种基金the National Social Commonweal Program (2001DIA50040-04) the Youth Foundation of the State Oceanic Administration of China (2000903).
文摘The solar wind almost disappeared on May 11,1999: the solar wind plasma density and dynamic pressure were less than 1cm^(-3) and 0.1 nPa respectively, while the interplanetary mag- netic field was northward. The polar ionospheric data observed by the multi-instruments at Zhong- shan Station in Antarctica on such special event day was compared with those of the control day (May 14). It was shown that geomagnetic activity was very quiet on May 11 at Zhongshan. The magnetic pulsation, which usually occurred at about magnetic noon, did not appear. The iono- sphere was steady and stratified, and the F_2 layer spread very little. The critical frequency of day- side F_2 layer, f_0F_2, was larger than that of control day, and the peak of f_0F_2 appeared 2 hours earlier. The ionospheric drift velocity was less than usual. There were intensive auroral E_s appearing at magnetic noon. All this indicates that the polar ionosphere was extremely quiet and geomagnetic field was much more dipolar on May 11. There were some signatures of auroral substorm before midnight, such as the negative deviation of the geomagnetic H component, accompanied with auroral E_s and weak Pc3 pulsation.
