海洋性大陆西部对流对若尔盖生态区夏季降水年际变化的影响  

Influence of Convection over the Western Maritime Continent on the Interannual Variability of Summer Precipitation in the Zoige Ecological Zone

作　　者：黄小梅 齐冬梅[1,2] 吕纯月 袁梦[2,4] 刘佳 HUANG Xiaomei;QI Dongmei;LYU Chunyue;YUAN Meng;LIU Jia(Sichuan Provincial Climate Centre,Chengdu 610072,China;Institute of Plateau Meteorology,CMA,Chengdu/Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China;Sichuan Provincial Meteorological Observation and Data Centre,Chengdu 610072,China;Sichuan Provincial Rural Economic Information Centre,Chengdu 610072,China;Research Center for Mountain Development,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610299,China)

机构地区：[1]四川省气候中心,成都610072 [2]中国气象局成都高原气象研究所/高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072 [3]四川省气象探测数据中心,成都610072 [4]四川省农村经济综合信息中心,成都610072 [5]中国科学院、水利部成都山地灾害与环境研究所山区发展中心,成都610041

出　　处：《高原山地气象研究》2025年第1期50-56,共7页Plateau and Mountain Meteorology Research

基　　金：高原大气与环境四川省重点实验室开放课题(PAEKL-2023-K06);四川省自然科学基金项目(2022NSFSC0230,2025ZNSFSC0333);国家自然科学基金青年科学基金项目(42205195)。

摘　　要：基于若尔盖生态区逐日降水量观测数据和NCEP/NCAR逐月再分析资料,研究1979—2020年若尔盖夏季降水量年际变化及其与热带海洋性大陆西部对流异常的联系。结果表明:(1)近42 a若尔盖生态区夏季降水量年际变化明显,20世纪90年代末和21世纪10年代初期存在显著的准2 a周期,4~6 a周期在20世纪90年代中后期表现显著。(2)年际尺度上,夏季海洋性大陆西部对流强度对若尔盖生态区降水量有显著的影响,即海洋性大陆西部对流偏强(弱)时,容易引起若尔盖降水偏多(少)。(3)在夏季海洋性大陆西部对流偏强时,西太平洋副热带高压偏强偏西,欧亚中高纬地区经向环流较强,低层风场在我国南部至西北太平洋表现为反气旋性环流异常,孟加拉湾北部至青藏高原南部为异常偏西南风,有利于西北太平洋和印度洋的暖湿气流输送到若尔盖生态区,导致降水偏多,反之亦然。Based on the daily observation data of summer precipitation in the Zoige ecological zone and monthly NCEP/NCAR reanalysis dataset,the interannual variation of summer precipitation in Zoige from 1979 to 2020 and its relationship with convective anomalies in the Western Maritime Continent(WMC)were studied.The results show that:(1)The summer precipitation in Zoige has obvious interannual variability,with 4-6a cycle in the mid-to-late 1990s and quasi 2a cycle in the late 1990s and early 2010s.(2)On the interannual time scale,there is a close relationship between the intensity of convection over WMC and the amount of summer precipitation in Zoige.When the convection over WMC is stronger(weaker),the summer precipitation in Zoige is more(less).(3)When the convection over WMC is stronger,the corresponding western Pacific subtropical high is significantly westward-shifted and intensified,the meridional circulation in the mid-high latitudes of Eurasia is stronger.The low-level wind field shows an anticyclonic circulation anomaly from southern China to the northwestern Pacific.There is an anomalous southwesterly wind from the northern Bay of Bengal to the southern Tibetan Plateau.These conditions are favorable for the transport of the warm and humid airflow from the northwestern Pacific and Indian Ocean to the Zoige ecological zone,resulting in more precipitation,and vice versa.

关 键 词：若尔盖生态区 降水 热带对流 夏季 年际变化 

分 类 号：P425.5[天文地球—大气科学及气象学] P461