The Spatial and Temporal Variability of Global Stratospheric GravityWaves and Their Activity during Sudden StratosphericWarming Revealed by COSMIC Measurements  

作　　者：Xiaohua XU Daocheng YU Jia LUO 

机构地区：[1]School of Geodesy and Geomatics,Wuhan University,129 Luoyu Road,Wuhan 430079,China [2]Collaborative Innovation Center for Geospatial Technology,129 Luoyu Road,Wuhan 430079,China [3]Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,129 Luoyu Road,Wuhan 430079,China

出　　处：《Advances in Atmospheric Sciences》2018年第12期1533-1546,共14页大气科学进展（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.41774033 and 41774032)

摘　　要：This study investigates the spatial and temporal variability of global stratospheric gravity waves(GWs) and the characteristics of GW activity during sudden stratospheric warming(SSW) using the GPS radio occultation measurements from the COSMIC mission during September 2006 to May 2013. Corresponding to the COSMIC RO observational window and analysis method,GW potential energy(Ep) with vertical scales no shorter than ～2 km is resolved. It is found that the distributions of GW Ep over 20-30 km and 30-38 km show similar spatial and seasonal variations. The variations of GW Ep with altitude and latitude along the westerly wind are identified in different seasons over 60°-80°W. In the middle and high latitudes,seasonal cycles are distinct in the time-latitude and time-altitude distributions of GW activities,which show larger Ep in winters when westerly wind dominates and smaller Ep in summers when easterly wind dominates. The influence of quasi-biennial oscillation on GW activity is recognized in the tropics. GW Ep enhances closely following the occurrence of minor SSW events; while during major events, GW Ep may not enhance, and sometimes may even weaken,in the regions where reversals of zonal wind occur, probably caused by the filtering impact of the 0 ms^(-1) wind level on the GWs.This study investigates the spatial and temporal variability of global stratospheric gravity waves(GWs) and the characteristics of GW activity during sudden stratospheric warming(SSW) using the GPS radio occultation measurements from the COSMIC mission during September 2006 to May 2013. Corresponding to the COSMIC RO observational window and analysis method,GW potential energy(Ep) with vertical scales no shorter than ～2 km is resolved. It is found that the distributions of GW Ep over 20-30 km and 30-38 km show similar spatial and seasonal variations. The variations of GW Ep with altitude and latitude along the westerly wind are identified in different seasons over 60°-80°W. In the middle and high latitudes,seasonal cycles are distinct in the time-latitude and time-altitude distributions of GW activities,which show larger Ep in winters when westerly wind dominates and smaller Ep in summers when easterly wind dominates. The influence of quasi-biennial oscillation on GW activity is recognized in the tropics. GW Ep enhances closely following the occurrence of minor SSW events; while during major events, GW Ep may not enhance, and sometimes may even weaken,in the regions where reversals of zonal wind occur, probably caused by the filtering impact of the 0 ms^(-1) wind level on the GWs.

关 键 词：STRATOSPHERIC gravity waves GPS radio OCCULTATION COSMIC potential energy SUDDEN STRATOSPHERIC WARMING 

分 类 号：P4[天文地球—大气科学及气象学]