“SZ-3”ATMOSPHERIC COMPOSITIONS DETECTOR MEASUREMENT RESULT——ABNORMAL CHANGE OF THE UPPER ATMOSPHERE COMPOSITION DURING GEOMAGNETIC ACTIVITY DISTURBANCE ON APRIL 2002

An atmospheric composition detector born on spacecraft "SZ-3" lunched on 26 March 2002. It met two times geomagnetic activity disturbance events during April 2002. "SZ-3" atmospheric composition detector measurements show the change and abnormal phenomenon of atmospheric composition on 330-350 km. Measurement results show that not only the responses of the O and N₂ density in creases during geomagnetic activity disturbance events, but also the phenomenon of the abnormal N₂ density increases and the abnormal O density decreases, during the peak of geomagnetic activity disturbance events, and it moved from 42°N to lower latitude （near 27°N） during 4-5 hours. The reason causing above mentioned phenomena might be relative to the energetic 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 changes. The latitude circulation moves the change from high latitude to lower latitude region.