中国廊坊中间层和低热层大气平均风观测模拟

摘要

利用中国廊坊站(39.4°N,116.7°E)流星雷达在2012年4月1日至2013年3月31日的水平风场观测数据,分析廊坊上空80～100 km的中间层与低热层(Mesosphere and Lower Thermosphere,MLT)大气平均纬向风和经向风的季节变化特征.结果表明平均纬向风和经向风都表现出明显的季节变化特征.平均纬向风在冬季MLT盛行西风,极大值位于中间层顶,随高度增加西风减弱;在夏季中间层为东风,低热层为强西风,风向转换高度约为82 km.平均经向风在冬季以南风为主,在夏季盛行北风.纬向风和经向风在春秋两季主要表现为过渡阶段.流星雷达观测结果与WACCM4模式和HWM93模式模拟的气候变化特点基本一致,但WACCM4模式纬向风和经向风风速偏大,而HWM93模式纬向风和经向风风速偏小.%By use of the observations of the meteor radar located at Langfang,China (39.4°N,116.7°E),the seasonal variation of mean winds in the Mesospheric and Lower Thermospheric (MLT) layer at 80～100km altitude over Langfang are studied.The time range of the observations is from 1 April 2012 to 31 March 2013.The results show that both the mean zonal winds and the mean meridional winds have obvious seasonal variations.In winter,westward winds prevail in the MLT,which are strongest in mesopause and decrease with increasing altitude.In summer,eastward winds dominate in mesosphere and decrease with increasing altitude,then turn to the strong westward winds at 82 km altitude in lower thermosphere.Usually,the mean meridional winds are southward in summer and northward in winter.The wind evolutions have the transition features in spring and autumn.The above main seasonal variations of mean winds are captured largely by the simulation of WACCM4 model and HWM93 model.However,WACCM overestimates the wind velocities,and HWM93 underestimates the winds velocities.