摘要：
The global morphologies of potential energy density Epfrom stratospheric gravity waves(GWs)are revealed by temperature profiles of COSMIC satellite from January 2007 to February 2013.The connection between Gws and latitudes,altitudes and seasons was discussed mainly,which indicate the medium-term variability of GWs in different latitudes.In the equatorial region, the activities of GWs are very strong all throughout the year and show clear QBO structure.The large gravity wave Epvalues found in tropics between -20°and 20°could be main-ly consistent with strong convective regions.In the mid-and high-latitudes,the GWs are strong in winter and weak in summer.In the mid-latitudes,the activities of GWs on continent are stronger than that on the sea in both hemi-spheres.Meanwhile,the activities of GW in Andes are relatively obvious except summer.In the high-latitudes,the distribution of GW remains stable in southern hemisphere,but in the northern hemisphere,some regions enhance and another weaken.This phenomenon may be related to SSW.By Lomb-scargle spectra analysis to GW perturba-tion,we found that QBO mainly in low latitude and AO and SAO in the mid-and high-latitude regions.%利用从2007年1月~2013年2月的COSMIC(constellation observation system for meteorology ionosphere and climate)温度数据,分析了平流层(20~35 km)的全球重力波活动及其随纬度、高度和季节的变化特征,揭示了平流层不同纬度重力波活动的中期变化规律;以及重力波振荡周期随纬度的变化.赤道地区重力波全年活动很强,且存在明显的准两年振荡(quasi-bi-ennial oscillation,QBO).在20°S~20°N的重力波势能极大值区与强对流区域保持一致.中高纬地区重力波主要表现为冬季强夏季弱.中纬地区,两个半球冬季陆地上重力波活动强于海洋,且南美洲南部安第斯山每年除夏季外,都有较明显的重力波活动.高纬地区,南半球冬季重力波分布保持稳定,而北半球则在某些区域增强,某些区域较弱,这一现象可能是与SSW (stratospheric sudden warming)相关.通过LS谱图分析,发现QBO主要出现在平流层低纬地区,AO(annual oscillation)和SAO (semiannual oscillation)则主要出现在平流层中高纬地区.
