东北冷涡低频活动对2023年6月6—13日辽宁地区降水的影响  

Influence of Low Frequency Activity of the Northeast Cold Vortex on Precipitation in Liaoning from June 6 to 13 in 2023

作　　者：苏小琁 谭政华 夏佳琦 孙艺搏 霍雅姝 孙晓蕾 Su Xiaoxuan;Tan Zhenghua;Xia Jiaqi;Sun Yibo;Huo Yashu;Sun Xiaolei(Liaoning Meteorological Observatory,Shenyang 110166,China;Institute of Atmosphere Environment,Key Laboratory of Northeast Cold Vortex Research,Shenyang 110166,China;Panjin National Climate Observatory,Panjin 124000,China)

机构地区：[1]辽宁省气象台,辽宁沈阳110166 [2]中国气象局沈阳大气环境研究所,东北冷涡研究重点开放实验室,辽宁沈阳110166 [3]盘锦国家气候观象台,辽宁盘锦124000

出　　处：《气象与减灾研究》2024年第4期243-252,共10页Meteorology and Disaster Reduction Research

基　　金：中国气象局沈阳大气环境研究所联合开放基金项目(编号:2023SYIAEKFMS12).

摘　　要：受东北冷涡低频活动影响,2023年6月6—13日辽宁省发生一次持续时间长的强降水事件。利用NCEP再分析资料,通过计算相关低频物理量场和Plumb波活动通量,对此次降水过程进行诊断分析。结果表明,此次降水事件是中高纬度环流系统低频调整的结果,欧亚大陆中高纬度位势高度自西向东呈现“负—正—负”异常分布,并伴随西太平洋遥相关型,东北冷涡在其负位相下产生。提前20 d上游地区(95°E)便出现正涡度信号,随后正涡度异常逐渐东传,并伴有低层、高层低频散度的辐合、辐散,为辽宁地区的降水及区域强对流发生发展提供了有利的动力条件。温度平流和涡度平流的共同作用下,东北冷涡得以发展维持,使得降水持续时间较长。低频降水发生阶段,辽宁地区上空整层的低频相对湿度均为正异常,并且前期受到高、低层暖气团和中层冷气团的控制,有利于对流的发生。乌拉尔山及我国东北地区为波活动通量异常大值区,Rossby波列促进了乌拉尔山附近高压脊以及东北冷涡的发展,造成了此次持续性强降水。On June 6-13,2023,a prolonged heavy rainfall event occurred in Liaoning Province due to the low-frequency activity of the Northeast Cold vortex.NCEP reanalysis data were used to calculate relevant low-frequency physical quantity fields and Plumb Wave Activity Flux to diagnose and analyze the precipitation process.The results indicated that this precipitation event was the result of low-frequency adjustment in the mid to high latitude circulation system.The height of the mid to high latitude potential in the Eurasian continent showed a“negative-positive-negative”anomaly from west to east,accompanied by a Western Pacific teleconnection(WP)pattern,and the Northeast Cold Vortex tended to generate under its negative phase.At 20 days lead time,a positive vorticity signal appeared in the upstream region(95°E),and then the abnormal positive vorticity gradually propagated eastward,accompanied by lowlevel low-frequency divergence convergence and high-level divergence,providing favorable dynamic conditions for precipitation and regional strong convection in Liaoning region.Under the joint action of temperature advection and vorticity advection,the Northeast Cold Vortex developed and persisted,resulting in a longer duration of precipitation.During the low-frequency precipitation stage,the overall level low-frequency relative humidity over the Liaoning region was positively abnormal,and in the early stage,it was controlled by warm air masses in the high and low layers and cold air masses in the middle layer,which was conducive to the occurrence of convection.The Ural Mountains and Northeast China are areas with abnormally high wave activity fluxes.The Rossby wave train promoted the development of high-pressure ridges near the Ural Mountains and Northeast Cold Vortex,resulting in this sustained heavy rainfall.

关 键 词：降水 东北冷涡 低频活动 波活动通量 辽宁地区 

分 类 号：P466[天文地球—大气科学及气象学]