青藏高原东南侧滇西北一次强降水天气过程分析  

Analysis of a Heavy Rainfall Process in the Southeast of Qinghai Tibet Plateau and Northwest Yunnan

作　　者：袁利平 杨朝梅 李希燕 汪靖 张万诚[3] YUAN Liping;YANG Chaomei;LI Xiyan;WANG Jing;ZHANG Wancheng(Meteorological Bureau of Nujiang Prefecture,Liuku 673199,China;Longli Meteorological Bureau of GuizhouProvince,Longli 522730,China;Yunnan Meteorological Institute,Kunming 650034,China)

机构地区：[1]云南省怒江傈僳族自治州气象局,云南六库673199 [2]贵州省龙里县气象局,贵州龙里522730 [3]云南省气象科学研究所,云南昆明650034

出　　处：《中低纬山地气象》2021年第3期24-32,共9页Mid-low Latitude Mountain Meteorology

基　　金：青藏高原东南角“桃花汛”暴雨的天气学成因及地形影响机制研究(42075013)。

摘　　要：利用常规观测资料、NCEP再分析资料、地形数据等,对2019年7月7—13日青藏高原东南侧滇西北地区持续性强降水天气过程进行综合分析。结果表明:西太平洋副热带高压控制中南半岛,伊朗高压稳定在印度西部附近,中高纬冷空气不断渗透南下,使印度东部低值系统长时间存在,其前部西南气流与副高西侧偏南气流汇合后持续影响滇西北,有利于孟加拉湾水汽向滇西北输送。强降水期间滇西北地区低层水汽通量散度呈负值,水汽辐合较强。整层大气低层辐合—高层辐散,上升运动强烈,抽吸作用明显;中低层大气高能高湿,处于对流不稳定状态。滇西北处于喇叭地形底部,两侧高大地形有利于引导水汽在滇西北汇聚,为持续强降水提供充足水汽;怒江州处于迎风坡,地形强迫抬升增强降水,使得怒江州降水量大于迪庆州和丽江市。Based on the conventional observation data,NCEP reanalysis data and topographic data,the continuous heavy precipitation weather process in Northwest Yunnan on the southeast side of Qinghai Tibet Plateau from July 7 to 13,2019 is comprehensively analyzed.The results show that:the Western Pacific subtropical high controls the Indo China Peninsula,the Iranian high is stable near the west of India,and the cold air in the middle and high latitudes continuously penetrates to the south,making the low value system in eastern India exist for a long time.The convergence of the southwest airflow in the front of the subtropical high and the southerly airflow in the west of the subtropical high continuously affects the northwest of Yunnan,which is conducive to the water vapor transportation from the bay of Bengal to the northwest of Yunnan.During the period of heavy rainfall,the divergence of low-level water vapor flux in Northwest Yunnan was negative,and the water vapor convergence was strong;the whole atmosphere convergence and divergence in the low-level and high-level,with strong upward movement and obvious suction effect;the middle and low-level atmosphere was in the state of convective instability due to high-energy and high humidity.Northwest Yunnan is located at the bottom of the trumpet terrain,and the high terrain on both sides is conducive to guiding the water vapor to converge in Northwest Yunnan,providing sufficient water vapor for continuous heavy rainfall;Nujiang Prefecture is located on the windward slope,and the topography forced uplift enhances the precipitation,which makes the precipitation in Nujiang Prefecture greater than that in Diqing Prefecture and Lijiang City.

关 键 词：滇西北 持续强降水 环流特征 物理量场 地形影响 

分 类 号：P458.121[天文地球—大气科学及气象学]