Observational Facts Of Surface Heating Fields In Arid Region Of Northwest China And Its Relationship With Summer Rainfall In Eastern China

The monthly surface heating fields in the arid region of northwest China in summer from 1982 to 2010 were calculated with the satellite remote sensing data and the observed date from 96 meteorological stations in northwest China. By comparing with 3 reanalysis data, and using mathematical statistics and empirical orthogonal function (EOF) methods, the basic climatic features of the surface heating fields are analyzed. Using SEOF methods, the surface heatting Index (1H) in arid region of northwest China was established. Then, find its relationship with summer rainfall in eastern China by using svd methods. The main conclusions are as follows:(1) The calculated value of surface heating fields is generally smaller than those three reanalysis data, but all of them have the same magnitude. The ERA-40 reanalysis data and the calculated value of surface heating fields are consistent in both spatial distribution pattern and interannual variations, while the calculated value of surface heating fields give more detailed information of the local climate characteristics.(2) The basic climatic features of the surface heating fields analyzed by the calculated data is consistent with the results of previous studies. As the latent heat flux only be strong in the east in summer, taking 100°E as the boundary, the surface heating fields in the eastern and western parts of northwest China vary significantly in terms of monthly change and interannual variation trends:The surface heating fields in eastern regions is stronger than those in western; The peak month of surface heating fields in the east (Jul) is later than it in the west (Jun). The summer surface heating fields in western and eastern have opposite interannual variation trends and the interannual variation trend of surface heating fields in eastern(western) is influenced by the sensible heat flux(latent heat flux), which varies from weak(strong) to strong(weak) during 1982-1995 and strong(weak) to weak(strong) during 1995-2010.(3) The main season’s anomalies propulsion of the sensible heat flux in western showing consistent seasonal variation. If the sensible heat flux be strong (weak) during the before winter, the late (spring, summer, autumn) always be strong (weak). The surface heatting Index (IH) in arid region of northwest China was established by using the average sensible heat flux anomaly of three stations (taxkorgan, Kumux and Shandan) which has a larger volume in both four seasons of the SEOF’s LV1. It can be representative rough underlying surface heat transport abnormalities.(4) The IH has a good correlation with the summer precipitation of the Eastern China. While the early (winter and spring) ground heat transport strong (weak), the summer precipitation in the Yangtze River region, eastern northwest, southwest and eastern Inner Mongolia should be less (more).