Characteristics of the Surface Sensible Heat on the Qinghai-Xizang Plateau in the Spring and Its Influences on the Summertime Rainfall Pattern over the Eastern China
ZHANG Changcan;LI Dongliang;WANG Hui;DAI Yifei;Key Laboratory of Meteorological Disaster,Ministry of Education ( KLME)/Joint International Research Laboratory of Climate and Environment Change ( ILCEC )/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters ( CIC-FEMD) ,Nanjing University of Information Science & Technology;
Based on the 70-station monthly surface Qinghai-Xizang Plateau sensible heat( QXPSH) data derived from the station observation data combined with the NASA-made normalized difference vegetation index( NDVI) data for the period of 1982-2012,the monthly summer precipitation data at 160 stations in the eastern China covering 1951-2012 and the monthly NCEP/NCAR I reanalysis data,the spacial-temporal variability of the QXPSH and its influence on the later summer rain pattern over the eastern China are analyzed through statistical method including EOF,SVD,etc. Results from observation and reanalysis dataset showthat:( 1) In the 1990 s,the Ⅲ rainfall pattern appears most times in China,and the eastern China experiences more frequent precipitation,especially regions along the Yangtze River. As the rainfall pattern shifts northward since the 21 st century,the II rainfall pattern began to increase.( 2) Generally,the spring( March-May) QXPSH is strong in the west but weak in the east. The surface sensible heat flux is strongest in May and its interannual variability is most obvious.On the spatial evaluation,there are two patterns of "consistent change"and "east-west reverse change",and they have a turnabout in 2003.( 3) When the spring QXPSH is on its negative( positive) phase,the high( low)pressure anomalies over northern China,the weak( strong) South Asian high that located westward( eastward),and the water vapor flux diverges in the vicinity of South China( Yangtze River and Hetao River),it results in the rainfall pattern shifting southward( northward) in the eastern China.
【Fund】： 国家自然科学基金项目(91337109 41305080);; 公益性行业(气象)科研专项(GYHY201506001-1);; 国家重点基础研究发展计划(973)项目(2013CB430202)
【CateGory Index】： P461
【CateGory Index】： P461