大气科学2017，Vol.41Issue(5)：1010-1026,17.DOI:10.3878/j.issn.1006-9895.1701.16245
由冬至夏北半球副热带地区大气热源的季节转换特征及其可能机制
Seasonal Transition of Atmospheric Heating Source in the Northern Hemisphere from Winter to Summer and Its Possible Mechanism
摘要
Abstract
Satellite observations and ERA-Interim reanalysis data have been used to investigate the seasonal transition of atmospheric heating source (AHS) in the Northern Hemisphere from winter to summer and its possible causes in the present study.Results show that the earliest formation of summertime diabatic heating occurs over South China in early April,which is closely associated with the development of rainy season to the South of Yangtze River.The sensible heating is dominant in the AHS during February-March when the major component of total rainfall is the large-scale precipitation.After early April,convective precipitation becomes more important,corresponding to increasing importance of condensation heating in the AHS.Diagnostic analysis suggests that seasonal changes in the thermal condition over the southern Tibetan Plateau (TP) are critical for this seasonal transition of the rainfall character and the AHS.During February-March,the sensible heating over the TP is becoming stronger with the enhancement of the solar radiation.The westerlies strengthen the warm advection in the middle troposphere over South China,leading to stronger ascending motions and large-scale precipitation that increase the soil moisture.This is favorable for the subsequent rapid development of local convective precipitation.Further enhancement of surface sensible heating over the TP can make low-level moisture to converge to the north by its "air pumping" effect during April-May,which intensifies the low level southerly winds.As a result,abundant water vapor are transported from the South China Sea and western Pacific to the South of the Yangtze River,where convective precipitation strengthens and the resultant condensation heating becomes dominant in the AHS.关键词
副热带大气热源/季节转换/江南春雨/青藏高原热力强迫Key words
Subtropical atmospheric heating source/Seasonal transition/Spring rainfall over the region to the South of Yangtze River/Thermal forcing of Tibetan Plateau分类
天文与地球科学引用本文复制引用
黄青兰,刘伯奇,李菲..由冬至夏北半球副热带地区大气热源的季节转换特征及其可能机制[J].大气科学,2017,41(5):1010-1026,17.基金项目
国家自然科学基金项目 41505049、41406033、91637312,中国气象科学研究院基本科研业务费专项 2015Z001、2017R001,广东省气象局科学技术研究项目 2016B47,江门市气象局气象科技项目 201403 （）
National Natural Science Foundation of China (NSFC) (Grants 41505049,41406033,91637312),Basic Scientific Research and Operation Foundation of Chinese Academy of Meteorological Sciences (CAMS) (Grants 2015Z001,2017R001),Science and Technology Research Project of Guangdong Meteorological Service (Grant 2016B47),and Science and Technology Research Project of Jiangmen Meteorological Service (Grant 201403) （NSFC）
