Impact of East Asian Summer Monsoon and Subtropical Anticyclone over Western Pacific on Droughts/Floods in Fujian

Based on 850 hPa NCEP/NACR wind and OLR data, different features of East Asian summer monsoon and the subtropical anticyclone over western Pacific between dry and wet years in Fujian Province are discussed. The main results are as follows: In the East Asian summer monsoon system, the intensity of tropical monsoon circulation strengthens (weakens) while the intensity of subtropical monsoon circulation weakens (strengthens), with a northward (southward)-slanted average location of the western Pacific high in wet (dry) years. During the seasonal transition from spring to summer and summer to autumn, the seasonal northward and southward jumps of the high ridge in wet years are quicker, inversely the jumps in dry years are slower. The "-+-" ("+-+") anomaly pattern dominates over East Asia at 500 hPa in wet (dry) years, i. e., there is not (is) blocking situation while the subtropical frontal zone moves northward (southward) in wet (dry) years. Results also show different features of the impacts of northward-and southward-slanted subtropical high locations on rainfall and their distributions in various months in summer in Fujian Province.