Numerical Study on Influence of the Persistent High Temperature and Drought in Midsummer on Short Term Precipitation in Middle and Lower Reaches of the Yangtze River

The effect of persistent high temperature and drought (PHTD) with different intensities on the short-term precipitation is simulated using IAP 2-L AGCM model with anomalies of underlying surface. The studied area covers the middle and lower reaches of the Yangtze River and the selected temperature data are limited to the midsummer time. It has been found that the PHTD affects the precipitation in the middle and lower reaches of the Yangtze River and southeastern coast of China significantly. The extent affected is differentiated by various intensities of PHTD. The results also show that the surface suitable high temperature and lower humidity in the area lead to the decreasing of short term precipitation and persistent high temperature and drought for about one month. The dominant factor is the variation of soil moisture rather than the soil thermodynamic properties in the positive feedback process