Scenario Analyses on Future Changes of Extreme Temperature Events over China

A regional climate model system, PRECIS, which is developed at the UK Met Office Hadley Centre for Climate Prediction and Research, and nested in one-way mode within the HadAM3P, a higher-resolution version of the atmospheric component of the Hadley Centre climate model HadCM3, is employed to verify the ability of the model to simulate the present (1961-1990) extreme temperature events and to project the future (2071-2100) extreme temperature events changes relative to the present in China under the IPCC SRES B2 scenario. It is indicated from the comparison of the simulated present results with observations that the localized fine-scale distribution characteristics of extreme temperature events in China can be simulated well by PRECIS. Under the IPCC SRES B2 scenario, the changes show there is an increase in hot days in most areas in China and the increase exceeds 500% for Northeast China, North China, Northwest China and Southwest China, while the changes also show that there is a decrease in frost days in most areas in China. The decreasing amplitude in northern China is smaller than that in southern China. There is an overall increase of the simulated future warm-spell days over most areas of China, an obvious increase occurs in Northeast China, North China, the middle and west of Northwest China and southeast coastal areas. There is a decrease of the simulated future cold-spell days over most areas of China. The decreasing amplitude is projected to reach or exceed 90% for Northeast China, North China, Northwest China, Inner Mongolia and the Tibetan Plateau.