神舟4号大气成分探测的新结果

神舟4号(SZ-4)大气成分探测器搭载在SZ-4留轨舱上于2002年12月30日发射入轨，在在轨运行的前3个多月中，正值地球南半球处于夏半球季节，并发生了多次中低强度的地磁扰动事件，SZ-4大气成分探测器测得了轨道舱运行高度上(330-362km附近)大气成分的响应变化和异常现象新结果．探测数据表明，中低强度的地磁扰动事件也能引起热层大气中主要成分O和N2的数密度值增高的响应变化．同样在进入地磁扰动峰期后较高纬度处出现了N2的异常增变和O的异常降变以及大气密度异常扰动的现象，但此期间所出现异常现象的地域与SZ-3和SZ-2大气成分探测器探测结果相反，它仅位于南半球较高纬度地区．

NEW RESULTS BY SZ-4 ATMOSPHERIC COMPOSITION MEASUREMENT

An atmospheric composition detector with a quadruple mass spectrometer on board spacecraft SZ-4 was launched on 30 December 2002. Based on the analysis of the three month's (2003-01-2003-03) data, during these months the summer just located at the southern hemisphere of the earth, and occurred some geomagnetic disturbances, the new results of the abnormal change of the thermospheric composition (near 330-362 km) are measured first. The results show that the density of N2 clearly increased, in contrast, the density of O showed a decrease, and occurred only at the higher latitudes of the southern hemisphere, during the peak of geomagnetic disturbances. It was quite different in comparison with the results of SZ-2 and SZ-3, where these abnormal change occurred at higher latitude of the northern hemisphere. The reason causing above mentioned phenomena might be related to the en ergetic particle input into the pole and high latitude region which heats the upper atmosphere in a large scale and produce a large scale air upstream which brings the air from lower altitude up to higher altitude and results in the above mentioned abnormal change. These abnormal change occurred at the different hemisphere, it seems that the abnormal change may occur only at hemisphere of Summer season.