资源环境科技发展态势分析平台

The impact of global warming on extreme precipitation over China is projected based on CMIP5 simulations under three representative concentration pathway scenarios. When global warming is 1.5 degrees C above pre-industrial (1861-1890), precipitation intensity and frequency increase, which leads to an increase relative to the period 1986-2005 in total wet daytime precipitation in northeast China, north China, and the Qinghai-Tibet Plateau. However, south China and southwest China experience fewer precipitation days and less total precipitation despite increasing simple daily intensity (SDII). Under 2 degrees C of warming, the number of wet days (R1mm) increases north of 30 degrees N and decreases to the south, whereas consecutive dry days (CDD) displays the opposite pattern. The other eight extreme precipitation events increase during the simulation period nationwide, with varying intensity. An increase in global warming from 1.5 to 2 degrees C is projected to lead to an increase in precipitation intensity over China, except for some scattered regions in the northwest and southwest of the country. More frequent extreme precipitation days are also expected, although decreases in R1mm are projected in north China and extend to northwest China. An overall small decrease in CDD is predicted for China. All annual regional-mean precipitation events have an apparent linear relationship with global mean temperature, except for CDD. The rate of increase of extreme precipitation with temperature in the future on an annual scale is much faster than for a reference period (1986-2005), whereas no noticeable difference exists on a daily scale. The relationships between daily precipitation extremes and temperature for the present day and for the future show a quadratic polynomial structure, increasing up to 19 degrees C but decreasing at higher temperatures. There is a significant positive influence on extreme precipitation when warming is limited to 1.5 degrees C, compared with a limit of 2 degrees C.