The Spatial and Temporal Variability of Global Stratospheric Gravity Waves and Their Activity during Sudden Stratospheric Warming Revealed by COSMIC Measurements
The Spatial and Temporal Variability of Global Stratospheric Gravity Waves and Their Activity during Sudden Stratospheric Warming Revealed by COSMIC Measurements
复制标题
宇宙测量揭示的全球平流层重力波的时空变化及其平流层突然变暖期间的活动
DOI：
10.1007/s00376-018-5053-1
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发表时间：
2018
影响因子：
5.8
通讯作者：
Luo Jia
中科院分区：
文献类型：
--
作者：
Xu Xiaohua;Yu Daocheng;Luo Jia
利用2006年9月至2013年5月的GPS无线电掩星观测资料，研究了全球平流层重力波(GWS)的时空变异性和平流层突然变暖(SSW)期间的GW活动特征。与宇宙RO观测窗口和分析方法相对应，求出了垂直尺度不小于∼2 km的GW势能。结果表明，GW EP在20-30公里和30-38公里范围内的分布具有相似的空间和季节变化。60◦-80◦W以上不同季节GW EP随海拔和纬度的变化。在中高纬度地区，GW活动的时间-纬度和时间-海拔分布具有明显的季节周期，表现为冬季西风占优势时EP较大，夏季东风占优势时EP较小。在热带地区，准两年振荡对GW活动的影响是公认的。GW EP随着SSW小震的发生而密切增强，而在重大事件期间，GW EP在发生纬向风逆转的地区可能不会增强，有时甚至可能减弱，这可能是0m S−1风高对GWS的过滤影响所致。
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 m s−1wind level on the GWs.