东经120°E中间层和低热层纬向风结构及变化特征

Global structure and variation of mesospheric and lower thermospheric zonal wind in 120°E meridian

利用热层-电离层-中间层能量和动力学卫星(TIMED)上搭载的多普勒干涉仪(TIDI)获取的为期9年的纬向风数据,考察了东经120°E子午圈中间层和低热层(MLT)平均纬向风的典型结构和变化特征.结果表明,在热带外尤其是中高纬度地区,TIDI观测结果与当前通用的中层大气经验模式有较好的一致性.但是在热带地区,观测与模式显著不同.在TIDI测量覆盖的所有高度(80—105km)上,热带地区纬向风持续地表现为东风,形成一个以赤道为中心的东风带.为期9年的观测数据显示,该东风带的宽度平均为37.5,平均变化幅度约为14.

Multiyear （2002-2011） wind observations from TIMED Doppler Interferometer （TIDI） onboard the thermosphere ionosphere mesosphere energetics and dynamics （TIMED） satellite are used for studying the typical structures and variations of mesospheric and lower thermospheric （MLT） mean zonal wind from 80 to 105 km in 120 °E meridian. Comparisons between TIDI measurements and empirical models indicate that TIDI is in good agreement with models in the extratropic regions especially in the middle and high latitudes, but significant differences occur mainly in the tropic regions. In the altitudes of TIDI＇s coverage from 80 to 105 km, monthly zonal winds are always westward over the tropical regions, forming an easterly band centered at the equator. Results from multiyear observations show complicated variations in the MLT tropical easterlies. The averaged width of easterlies is 37.5 degrees and corresponding variation is about 14 degrees.