SVD Analysis Of The Relationship Between Jianghuai Region Meiyu Season Precipitation And The Sea Surface Temperature And Related Numerical Simulation

With the view to climate, and based on the searching for the correlativity between the SST and Meiyu precipitation, this dissertation has numerical simulation experiments for the relationship between regional climate in Jianghuai and SST, and tries to search for mechanism of SSTA causing Meiyu precipitation in Jianghuai to vary. The results show:(1) There is positive correlation between Meiyu precipitation in Jianghuai south and SSTA( 10-12 monthly averaged in former year) in Southern China Sea, and the SST distribution pattern including the key region(6 °N—22°N, 114°E—124°E) is positive west and negative east.(2) There is also apparent correlation between Meiyu precipitation in Jianghuai south and SSTA( 8-12 monthly averaged in former year) in equatorial eastern Pacific Ocean, especially the higher correlation in the key regions(10 °S-0, 120-100°W).(3) In fact, the two SST distributions mentioned above belong to the same SST distribution pattern, but the regions influenced by the two SST distribution are different from each other.(4) Numerical simulations including positive and negative experiments in Southern China Sea can fully illuminate that when SST around the key regions increases or decrease, airflow over 850 hpa converge more or disperse more in Jianghuai south, and oceans provide more or less water vapor to Jianghuai south. As a result, Meiyu precipitation grows up or cuts down.(5) There are rather apparent positive correlations between Meiyu precipitation in Jianghuai north and SSTA (1-2 monthly averaged in the present year) in northern Pacific Ocean around (150 °E-165 °E , 42 °N-47 °N) , and between the former and SSTA (10-12 monthly averaged in the former year) in easternAtlantic Ocean. The Jianghuai north and the two key regions are significant regions in couple.(6) Results of positive numerical experiments in northern Pacific Ocean are better than those of negative ones. The results of the former can generally show that when SST around the key regions increase, airflow over 850 hpa converge more in the Jianghuai north, and more water vapor is transported to Jianghuai north by oceans. Therefore, Meiyu precipitation will be fortified.