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Abstract:
The winds of 80-100 km observed by Mohe (53.5ºN , 122.3ºE，MLAT：48.3ºN), Beijing (40.3°N , 116.2°E，MLAT：34.9 ºN) and Wuhan (30.5°N , 114.2°E，MLAT：24.8ºN) Meteor radars are used to study the responses of the MLT winds to geomagnetic activities. Geomagnetic conditions are classified to quiet periods (Kp<=2) and disturb periods (Kp>=4). The results show that the influence of geomagnetic activitys on the MLT winds varied with seasons and latitudes. For zonal wind, the effect of geomagnetic activity at higher latitudes tended to be more westerly wind in the upper mesosphere and more easterly wind in the lower thermosphere. in summer/winter, the easterly wind in the middle atmosphere became stronger with the decrease of latitude. For meridional wind, in spring and winter it was stronger than that in summer and autumn. In winter, the meridional wind in middle and low latitudes was stronger than that in higher latitudes. Basically, the influence of geomagnetic activities reaches ~ 5-10 m/s for zonal winds, and reaches 3-5 m/s for meridional winds.
