长江中下游盛夏持续性高温干旱对短期降水影响的数值试验

应用IAP 2-L AGCM模式，并考虑了下垫面异常，模拟了长江中下游盛夏不同强度的持续性地表高温干旱对短期天气的影响。结果表明，这种持续性高温干旱对长江中下游及我国东南沿海短期降水有十分明显的影响，持续高温干旱的强度不同，其影响结果不同。持续性适度高温和严重干旱造成短期降水减少，高温干旱仍继续维持达1个月的正反馈过程。在此持续过程中，土壤湿度变化起主导作用，而土壤热力状况的影响相对较小。

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