中文摘要：

本文利用2001年至2005年间CHAMP卫星及DMSP（F13,F15）卫星观测数据,对亚暴发生前后,亚暴初始位置所在磁地方时（Magnetic Local Time,MLT）东侧2h（＋2h,MLT）至西侧4h（-4h,MLT）范围内等离子体对流速度（Vy）及热层纬向风速度（Uy）的变化进行了统计学分析.研究发现在亚暴发生后的1.5h内,所有MLT区间的Vy均明显增大,且峰值位置的地磁纬度向赤道侧移动,1.5h后,Vy减小,峰值的纬度向极区移动,表明亚暴的发生能显著增强等离子体对流速度;在亚暴发生位置的西侧0-2h内,Vy增幅最大,这表明亚暴对热层的影响主要在西侧,影响最大的区域是西侧0-2hMLT区间;Uy在亚暴发生后3h持续增大,其对亚暴的响应相较于Vy有1.5h的延迟.

英文摘要：

This study statistically investigates the temporal and spatial variations of plasma convection velocity（Vy）and thermospheric zonal wind velocity（Uy）in the range of-4hour（h）and ＋2h MLT relative to substorm onsets（MLT onset）with both CHAMP and DMSP（F13,F15）satellite observations from 2001 to 2005.It shows that Vyincreases significantly in all MLT sectors and the latitudes of the peak values move equatorward in 1.5hafter substorm onsets.In the subsequent 1.5hVydecreases in intensity and the peaks retreat poleward,which shows that the onsets of substorm can enhance the plasma convection velocity dramatically.The relative increase of Vyis the largest from-2hto MLT onset,which indicates that the substorm mainly affects the thermosphere in the westward 0-2h MLT sector.Uyincreases steadily in 3hours after substorm onsets,with an 1.5hdelay relative to Vyin the response to the substorm onsets.