Spatiotemporal patterns of future temperature and precipitation over China projected by PRECIS under RCPs

摘要

In this study, the spatiotemporal patterns of future temperature and precipitation changes over China are explored with the regional climate model PRECIS at two horizontal resolutions (25 km and 50 km). The gauge based temperature (CN05.1) and precipitation data (APHRODITE) are used to validate the performance of PRECIS. The results show that PRECIS has better performance in reproducing the present climatology in spatial distribution and annual cycle than its driving GCM, particularly in some cold months and the high latitude regions, though the simulation is worse in precipitation over the high-cold Tibet Plateau of China. Compared to the observation, the difference between the simulations at 50 km (R50) and 25 km (R25) resolutions is very small. Projected annual temperature and precipitation will increase gradually with the time over most regions of China, especially in the late of this century. The results from R25 show the mean temperature over China will increase by similar to 1.3(1.5) degrees C in the early century, 2.7(3.5) degrees C in the middle century, and 3.5(5.9) degrees C in the late century under RCP4.5(8.5), which are all smaller than the values from its driving GCM. Most models project that the temperature will have more increases in cold months (i.e., January to March) while the southeastern region will show smaller changes relative to other sub-regions. Additionally, China will receive more precipitation from the overall trend, but the increased amplitude among different concentration scenarios and models are different obviously. The projections from R25 show more precipitation than the R50 and their driving GCM. For instance, the annual mean precipitation will increase by similar to 15(22) % for GCM, similar to 20(33) % for R50 and similar to 22(37) % for R25 in the late of this century over the entire China under RCP4.5(8.5). The annual cycles of precipitation at subregions also show a distinct variation. The changes are smaller in October or November than other months for the southeastern and central regions, while the percentage change is larger in the northwest, which will alleviate the pressure of water shortage in this arid region of China.