基于COSMIC RO数据分析青藏高原下平流层重力波的活动特征  

Analysis of Activity Characteristics of Lower Stratospheric Gravity Waves over the Qinghai-Tibet Plateau Based on COSMIC RO Observations

作　　者：高雨 陈志平 GAO Yu;CHEN Zhiping(Faculty of Geomatics,East China University of Technology,330013,Nanchang,PRC;Key Laboratory of Mine Environmental Monitoring and Improving around Poyang Lake,Ministry of Natural Resource,330013,Nanchang,PRC)

机构地区：[1]东华理工大学测绘工程学院,南昌330013 [2]自然资源部环鄱阳湖区域矿山环境监测与治理重点实验室,南昌330013

出　　处：《江西科学》2023年第1期87-93,共7页Jiangxi Science

基　　金：国家自然科学基金项目(41904031,42061077,41806114);江西省自然科学基金项目(20202BABL213033,20202ACBL214019);大地测量与地球动力学国家重点实验室开放基金项目(SKLGED2021-2-2);江西省数字国土重点实验室开放基金项目(DLLJ201905);东华理工大学博士启动基金项目(DHBK2018006);江西省研究生创新基金项目(YC2021-S615)。

摘　　要：重力波的传播及其动力学效应对下平流层的大气环流具有重要影响,通过高时空分辨率的观测资料获取下平流层重力波的相关参数,有利于提高大气循环模式的预报精度和可靠性。利用2006年8月至2016年7月COSMIC(the Constellation Observing System for Meteorology,Ionosphere,and Climate)掩星(Radio Occultation,RO)任务反演的干温廓线,通过S变换,纬向滤波等处理,提取表征重力波活动的参数——势能。以此分析了青藏高原重力波的垂直分布特征和空间分布特征。青藏高原上空的重力波势能存在明显的先减小后增大的垂直分布。对流层顶以下的势能因较小的浮力频率而异常较大;在对流层顶至0风场线,强西风促进重力波的向上传播,势能值相对较大;0风场线对地形激发的准静态重力波存在过滤作用,势能值在0风场线处急剧减小;36 km以上的重力波势能受到强西风的影响而异常增大。青藏高原下平流层的重力波活动有明显的季节变化,重力波活动在冬季较强,夏季较弱。在18~20 km、20~22 km高度,重力波势能的分布在春季、夏季、秋季相似。在冬季,在18~20 km高度,势能的分布更集中,势能值更大,该现象主要存在高原东南部。高原边缘存在重力波势能较大的区域,这可能与重力波激发时的地形和背景风有关。The propagation and dynamic effect of Gravity wave(GW)have an important influence on the atmospheric circulation in the lower stratosphere.It is beneficial to improve the prediction accuracy and reliability of atmospheric circulation model to obtain the relevant parameters of GW in the lower stratosphere through high spatial and temporal resolution observations.In this paper,the dry temperature profile retrieved from COSMIC(the Constellation Observing System for Meteorology,Ionosphere,and Climate)Radio Occultation mission from August 2006 to July 2016 was used to extract GW potential energy(Ep)through S-transformation,zonal filtering and other processing.The vertical and spatial distribution characteristics of GWs over the Qinghai-Tibet Plateau(TP)were analyzed.The GW Ep over the TP has an obvious vertical distribution,which decreases first and then increases.The Ep below the tropopause is large due to the small Brunt-V?is?l?frequency.In the tropopause to zero speed wind,the strong westerly wind promotes the upward propagation of GWs,and the Ep value is relatively large.The zero speed wind filters the quasi-static GW excited by the topography,and the Ep decreases sharply at the zero speed wind.The GW Ep above 36 km is abnormally increased by the strong westerly wind.The GW activity in the stratosphere over TP has obvious seasonal variation,and the GW activity is stronger in winter and weaker in summer.At the height of 18~20 km and 20~22 km,the distribution of GW Ep is similar in spring,summer and autumn.In winter,the Ep distribution is more concentrated at 18~20 km.And the Ep value is larger,which mainly exists in the southeast of TP.At the edge of TP,the GW Ep is relatively large,which may be related to the topography and background wind when GWs are excited.

关 键 词：重力波 COSMIC掩星 青藏高原 活动特征 

分 类 号：P405[天文地球—大气科学及气象学]