Projection And Evaluation Of Precipitation In China By Models

Using the outputs as simulated by GCM models provided by DDC of IPCC and RCM model, We analyze the simulation and future changes of precipitation under different scenarios in China.Compared with daily precipitation of 550 stations in China, We assess the simulation capacity of thirteen GCM models. Most models can simulate the inter-annual change and spatial distribution of climate field, but the simulation of the East is better than other areas, and there are false high values in the east and south of Plateau. The situation of precipitation change in China in the future 100 years under SRES A2,A1B and B1 greenhouse gas is analyzed. The results show that the precipitation would be increased by 11%,9.6% and 6.4% at the end of 21st century with the mean of 7.5% .The distributions of precipitation in China were analyzed in this paper. And the distributions of precipitation are almost similar in all the scenarios too. The results indicated that the distribution of increased precipitation in China is in northern of China, there are obviously increase of precipitation in north of China,northwest and northeast, and there are a little increase in the south of Yangtze River. The increase of precipitation is larger in winter and spring. Compare with results of Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-TAR), the ensemble standard deviation of different models suggests that the uncertainty of the projected precipitation changes over China in the 21^st century has been improved.A variable-grid atmospheric general circulation model, the LMDZ, with a local zoom over the middle-east area of China is used to investigate the changes of precipitation at present and future (we called LMDZ-regional in this paper). LMDZ-regional model can simulate the inter-annual change,frequency of daily precipitation and spatial distribution of climate field, but the simulation of the East is better than other areas. Precipitation is larger than observer in the north of Yangtze-River, and less in the south. The model can also simulation changes of parameters and return values of GEV distribution of daily maximum precipitation, but the center locates northerly. The situation of precipitation change in middle-east area of China in future under SRES A2,A1B and B1 greenhouse gas is analyzed. The results show that frequency of trace precipitation will increase in winter, but frequency of both trace and strong precipitation will decrease. The distributions of precipitation in middle-east area of China were analyzed in this paper. The results indicated that annual average precipitation will increase a little in the north of Yangtze River, and decrease in the north from zero to 0.4mm/day. Daily maximum precipitation in the center of Hubei,the junction of sichuan and shanxi will decrease, and increase more in 30-yr return values in Henan and northern of Jiangsu, the increases will arrive 40mm/day.