中国东部春季极端降水与同期欧亚大陆地表感热的可能联系  

Possible Linkage between Spring Extreme Precipitation over East China and Surface Sensible Heat Flux over the Eurasian Continent

作　　者：沈迪桑 陈海山[1] 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心/气候与环境变化国际合作联合实验室/气象灾害教育部重点实验室,南京210044

出　　处：《气候与环境研究》2018年第1期103-112,共10页Climatic and Environmental Research

基　　金：科技部公益性行业(气象)科研专项GYHY201206017;国家自然科学基金项目41230422;41625019;江苏省自然科学基金项目BK20130047;"新世纪优秀人才支持计划"~~

摘　　要：利用1960~2010年ERA-20C再分析资料和中国东部站点降水观测资料,探讨了我国东部春季极端降水与欧亚大陆地表感热通量的联系和可能影响途径。结果发现,当春季欧亚大陆中纬度巴尔喀什湖以西及贝加尔湖以南区域地表感热通量偏弱(强),我国东部沿海地区地表感热通量偏强(弱)时,我国东部春季极端降水呈现南少(多)北多(少)的反相分布特征。当春季欧亚大陆中纬度关键区地表感热偏弱,低纬度关键区地表感热通量偏强时,春季副热带西风急流偏弱、位置偏北,我国东部北方地区大气斜压不稳定和对流不稳定偏强,北方地区极端降水偏强,而南方地区大气斜压不稳定和对流不稳定偏弱,南方地区极端降水偏弱。当春季欧亚大陆中纬度关键区地表感热偏强,低纬度关键区地表感热通量偏弱,我国东部极端降水的情况大致相反。Based on the ERA-20C reanalysis data and observational precipitation data collected at the 332 stations in eastern China(to the east of 105°E) during 1960-2010,the possible linkage between spring extreme precipitation over eastern China and surface sensible heat flux over the Eurasian Continent is explored.Results show that when weakened(intensified) spring surface sensible heat flux occurs in the middle latitudes of the Eurasian Continent(i.e.,regions to the west of Lake Balkhash and to the north of Lake Baikal) while intensified(weakened) sensible heat occurs in eastern China,the spring extreme precipitation is usually more(less) than normal over northern China but less(more) than normal over southern China.Further analysis suggests that weakened sensible heat in the middle latitudes and intensified sensible heat in the lower latitudes tend to weaken spring subtropical westerly and shift it northward,which are favorable for enhanced convective and baoclinic instabilities,leading to more extreme precipitation in North China.However,they tend to decrease baroclinic and convective instabilities and result in less extreme precipitation in South China.On the contrary,intensified sensible heat in the middle latitudes and weakened sensible heat in the lower latitudes tend to have opposite effects.

关 键 词：地表感热 欧亚大陆 极端降水 中国东部 

分 类 号：P461[天文地球—大气科学及气象学]