Community Climate Model 3模拟夏季极端降水的初步分析

采用累积频率的统计方法和Community Climate Model 3(CCM3)模拟的10年逐日降水结果,分析了模拟的夏季极端降水事件的时空分布特征.结果表明,CCM3模拟的极端降水阈值的大值区主要在我国黄河和长江流域的上游、印度半岛及其邻近海域和孟加拉湾及其北部地区.CCM3能够模拟出我国长江流域极端降水量与极端降水日数显著增加的趋势.对极端降水平均强度、降水日数以及极端降水量与总降水量比值的经验正交函数(EOF)分析可知,我国大部分地区的极端降水基本呈现同相变化,且以长江和黄河中游地区较为显著.CCM3模式基本能够模拟出观测到的极端降水阈值与总降水、极端降水日数及其距平的高空间相关性.

The Elementary Analysis of Summer Extreme Precipitation Events Simulated by Community Climate Model 3

By use of the threshold value of the cumulative frequency and 10 years' daily precipitation results simulated by Community Climate Model 3(CCM3),the spatial distribution characteristics of the summer extreme precipitation events are analyzed.The results show that areas of larger threshold values of the summer extreme precipitation are located in the uppar reaches of the Yellow River and the Yangtze River,the India Peninsula and its adjacent waters,and the Bay of Bengal and its northern areas.The remarkably increasing trends of both the extreme precipitation amount and the number of days in the Yangtze River Valley are fairly simulated by the model.By using the EOF analysis,the temporal and spatial features of the average intensity of the extreme precipitation,the day number and the ratio of the extreme precipitation to the total one are depicted.It is found that their temporal variations in most areas of China are in phase,and the more evident temporal changes take place in the Yangtze River Valley and the middle Yellow River.CCM3 basically simulates the observed high spatial correlations between the threshold values of the extreme precipitation,the total precipitation amount and the day number of the extreme precipitation,and their anomalies with each other are correctly simulated with the CCM3.