贵州暖季降水时空分布及其与大气环流异常的关系  

The Spatio-temporal Distribution of Precipitation During Warm Season in Guizhou and Its Relationship with Atmospheric Circulation Anomalies

作　　者：严小冬 夏阳 任曼琳 张皓 YAN Xiaodong;XIA Yang;REN Manlin;ZHANG Hao(Guizhou Institute of Mountain Meteorological Science,Guiyang 550081,China;Qingzhen Meteorological Office of Guizhou Province,Qingzhen 551400,China)

机构地区：[1]贵州省山地气象科学研究所,贵州贵阳550081 [2]贵州省清镇市气象局,贵州清镇551400

出　　处：《山地气象学报》2024年第6期1-8,共8页Journal of Mountain Meteorology

基　　金：贵州省气象局省市联合科研基金项目(黔气科合SS[2023]32号);贵阳市科技计划项目(筑科合同[2020]7-3)。

摘　　要：【目的】为进一步加强对于贵州暖季降水气候规律的认识,提升贵州暖季降水的预测能力。【方法】基于站点降水观测资料、NCEP/NCAR全球再分析资料和HadISST海温资料等,利用多种气候统计方法对贵州暖季降水的时空分布特征及其与异常环流之间的联系进行分析。【结果】贵州暖季降水及其占全年降水量的百分比总体呈现南多北少、西多东少的分布特征,其中西部的干湿季差异更为显著,降水具有更强的集中性;贵州暖季降水存在显著的年际(年代际)变化特征和准20 a、准7 a振荡周期;贵州暖季降水分布与前期的印度洋和大西洋局部区域的海温指数,以及同期的副高脊线和东亚槽位置指数存在显著的相关;当贵州暖季降水异常偏多时,北半球极涡向乌拉尔山和加拿大北部地区有延伸的槽区存在,东北亚地区西高东低的环流形势有利于环流经向度的加大和引导冷空气南下影响中国南方地区,伴随贵州北侧上空存在的异常正经圈环流上升支共同影响,使得孟加拉湾和南海的水汽在贵州境内产生明显的辐合抬升,为降水的形成提供有利条件;贵州暖季降水异常分布还与前期秋冬季的北太平洋和北美西海岸、西太平洋,以及北大西洋和赤道大西洋等地区的海温异常密切相关。【结论】研究揭示了贵州暖季降水的时空分布特征及其与异常环流、前期海温的显著联系,为提升贵州暖季降水预测能力提供了科学依据。To strengthen the understanding of the climatic patterns and enhance the prediction ability of precipitation in Guizhou during the warm season(PGWS),based the precipitation observation data,NCEP/NCAR reanalysis data,and HadISST sea surface temperature data,we analyze the spatial and temporal distribution characteristics of PGWS and its relationship with abnormal circulation by various climate statistical methods.The results show that the distribution of PGWS and its percentage of the annual precipitation generally present the pattern of more in the south and less in the north,more in the west and less in the east.In western Guizhou,difference between the dry and wet seasons is more significant and precipitation has an even stronger concentration.There are significant interannual(inter-decadal)variations and quasi-20 years and quasi-7 years oscillation periods of PGWS.The distribution of PGWS is significantly correlated to the SST in the Indian Ocean and Atlantic Ocean in the previous period,and is also associated with the position indexes of subtropical high ridge line and East Asian trough during the same period.When there is excessive PGWS,there is a trough extending from the polar vortex in the Northern Hemisphere towards the Ural Mountains and northern Canada,and the circulation pattern of high west and low east in Northeast Asia is conducive to the strengthening of meridional circulation,guiding the cold air southward to affect southern China.This is accompanied by the abnormal positive circulation ascending branch over the northern side of Guizhou,and the two jointly affect the convergence and uplift of water vapor from the Bay of Bengal and the South China Sea within Guizhou,providing favorable conditions for the formation of precipitation.The distribution of PGWS is also closely related to the SSTA in the North Pacific,the west coast of North America,the western Pacific,the North Atlantic,and the equatorial Atlantic during the previous autumn and winter.Overall,this study reveals the spatial and temporal

关 键 词：贵州 暖季降水 时空分布 环流异常 

分 类 号：P426.614[天文地球—大气科学及气象学]