The Anormaly Of The Surface Sensible Heat Of The Tibetan Pleteau In The Boreal Spring And Its Influences On The Summertime Rainfall Pattern In China

Based on the monthly 70-stations Tibetan pleteau surface sensible heat (TPSH) data from the the station observation data in combination with the NASA center for the normalized difference vegetation index data, the NCEP/NCAR reanalysis monthly data from 1982 to 2012 and the monthly precipitation of summer data at 160 stations in the eastern China from 1951 to 2012, the spacial-temporal variability of the surface sensible heat in the Tibetan pleteau and the summer precipitation over the eastern China has been analyzed. Meanwhile, the relationship between the spring sensible heat and the summer rain belt has been found, and the reason of the relationship has also been analyzed by the east Asian atmospheric circulation, the results show that:(1) In the 1990s, China is dominated by the III rainfall pattern, and the eastern China experiences more frequent precipitation, especially regions along the Yangtze River. The typical and not typical rainfall pattern is defined by the similarity index of the summertime rainfall over the eastern China with the distribution of the three kinds pattern.When the largest similary index is less than 0.187, than the rainfall pattern is not typical; on the contrary, the pattern is typical.(2) Generally, the spring (March-May) TPSH is intense in the west but weak in the east, which has changed little during 1982-1988. However, it has been decreasing for the period 1988-2003 and anomalous positive (negative) TPSH is found in the west (east), while reverses to increase after 2003 and positive (negative) TPSH anomaly is seen in the east (west). Three kinds of TPSH data show that all of them is distribution of unimodal type, the site of TPSH is alike with NCEP2 in spacial distribution and temporal evolution.(3) When the sensible heat stronger, the ’-+-’ wave train structure of summertime high latitude in the 500hPa, and the long wave trough is over the north China,the south asian high is stronger, and its location is easter, the whole layer moisture flux convergence location in Yangtze-Huaihe River, then the rain-band is further north, the possiblility of the rainfall pattern II is higher; when the sensible heat weaker, the circulation is on the contrary with the TPSH is stronger, rain blet is more southern, the possiblility of the rainfall pattern III is higher.(4) China summer rain belt prediction model:EUI index greater than 2 for I rainfall pattern; TPSH index is greater than 0 for II rainfall pattern, index less than 0, it is III rainfall pattern.