RCP4.5情景下中国季风区及降水变化预估

Projection of Monsoon Area and Precipitation in China under the RCP4.5 Scenario

本文使用国际耦合模式比较计划第五阶段（CMIP5）中共46个全球气候模式的数值试验结果，通过对中国区域的年、夏季和冬季降水气候态的模拟能力评估，择优选取了18个气候模式用来预估RCP4.5情景下21世纪中国季风区范围、季风降水及其强度变化。结果表明，相对于1986～2004年参考时段，RCP4.5情景下多数模式和所有模式集合平均在不同时段内均模拟出中国季风区面积、季风降水及其强度的增加趋势，最明显的时段出现在2081～2099年。其中，季风区面积扩张是导致季风降水增加的主要因素。在机制上，热力与动力条件变化均有利于季风降水强度的增加以及更多的水汽进入中国东部，从而引起季风区范围的扩大。

The capabilities of 46 CMIP5 （the Coupled Model Intercomparison Project Phase five） models for simulating the annual, summer, and winter precipitation climatology over China are first examined using the outputs of these models from historical data for the period 1986？2004. Eighteen models are then chosen to project the changes of monsoon area, monsoon precipitation, and monsoon precipitation intensity over China under the Representative Concentration Pathways 4.5 （RCP4.5） scenario. The results show that the monsoon area, monsoon precipitation, and monsoon precipitation intensity will increase in the 21st century, particularly during 2081？2099. The increase in the monsoon precipitation is mainly derived from the increase in the monsoon area. Both thermal and dynamic conditions will be favorable for increased monsoon precipitation intensity and greater water vapor transport into eastern China, resulting in the expansion of the monsoon area in China.