哀牢山两侧夏季降水差异的时空分布特征和季风的相关性研究  

The Spatial-temporal Distribution of the Difference in Summer Precipitation Difference Over Two Sides of the Ailao Mountain and Its Relationship with Monsoons

作　　者：连钰 许彦艳[1,2] 李华宏 蔡磊[3] LIAN Yu;XU Yanyan;LI Huahong;CAI Lei(Meteorological Observatory of Yunnan Province,Kunming 650034,Yunnan,China;Research Center for Disastrous Weather over Hengduan Mountains&Low-Latitude Plateau,CMA,Kunming 650034,Yunnan,China;Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion,Kunming 650091,Yunnan,China)

机构地区：[1]云南省气象台,云南昆明650034 [2]中国气象局横断山区(低纬高原)灾害性天气研究中心,云南昆明650034 [3]云南省大湄公河次区域气象灾害与气候资源重点实验室,云南昆明650091

出　　处：《高原气象》2024年第4期1026-1038,共13页Plateau Meteorology

基　　金：国家自然科学基金项目(42105021);云南省重点研发计划-社会发展专项(202203AC100005);中国气象局创新发展专项(CXFZ2022J021);云南省气象局创新团队项目(2022CX02)。

摘　　要：运用国家站观测资料、全球气候再分析资料和数值模式敏感性试验数据,对哀牢山两侧夏季总降水量差异及其影响云南省夏季气候的主要季风系统-东亚夏季风和印度夏季风的关系进行了分析。结果表明:哀牢山主脉西侧夏季总降水量明显大于主脉东侧。比较哀牢山主脉两侧的5组国家站观测数据显示,哀牢山主脉南部夏季总降水量差异高于北部夏季总降水量差异,并且哀牢山主脉北部两侧夏季总降水量差异与主脉南部两侧夏季总降水量差异呈现出一定的负相关性。5组站点夏季总降水量差异整体与东亚夏季风指数呈负相关关系,与印度夏季风指数呈正相关关系。哀牢山两侧站点夏季总降水量差异与季风交界面指数的相关性要高于其与单一东亚夏季风或印度夏季风的相关性。通过分别选取季风交界面指数正负异常年,并交换风场或水汽边界条件设计数值模式敏感性试验,定量探究两支季风的相对强弱对于哀牢山两侧站点夏季总降水量差异的贡献。结果表明,两支季风共同控制的异常风场是造成哀牢山两侧夏季总降水量差异的主要原因。相比之下,季风带来的水汽条件差异对于哀牢山两侧的夏季总降水量有着相近的影响,对于夏季总降水量差异变化的贡献较弱。This study examines the inter-annual variation of the difference in summer precipitation over the east and west side of the Ailao Mountain,as well as its relationship between the East Asia summer monsoon and the South Asia summer monsoon based on in situ observations,reanalysis products and model sensitivity experiments.As the result,climatological statistics show that there is more precipitation on the west side than on the east side of the Ailao Mountain.Compared to the total summer precipitation amount observed over five pairs of state-level weather stations,the difference is higher on the north part than on the south part,with negative correlations to some extent.The observed differences in precipitation are generally with a negative correlation between the East Asia summer monsoon index,and with a positive correlation between the South Asia summer monsoon index.The linear correlation coefficients with the index of monsoon interface,which stands for the relative strengths of the East Asia and South Asia monsoons,are higher than those with one single monsoon.With one positive and one negative year selected based on the index of monsoon interface,we design and conduct a set of model sensitivity experiments through changing the boundary condition of wind and water vapor fields respectively to quantify the impact on precipitation difference of monsoons.The result shows that the anomaly in the wind field is the major contributing factor of the difference in precipitation on the two sides of the Ailao Mountain.On the other hand,the anomaly in the water vapor field makes synchronized changes in precipitation on both sides of the mountain,while it contributes little to the precipitation difference.

关 键 词：哀牢山 降水 数值模拟 印度夏季风 东亚夏季风 

分 类 号：P466[天文地球—大气科学及气象学]