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
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 show that:(1) In the 1990s,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 21st 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.
Sensible heat in Qinghai-Xizang PlateauRainfall patternEastern Asian atmospheric circulation
NETL
NSTL
万方数据
维普
