IPCC AMIP模式对西南澳类季风环流的模拟

Evaluation of IPCC AMIP Models in Simulating Monsoon-Like Southwest Australian Circulation

以西南澳类季风环流为出发点,考察了IPCC第四次评估报告AMIP提供的12个大气环流模式对于澳大利亚西南部(SWWA)地区降水的季节演化特征,西南澳类季风环流(SWAC)的季节特征、季节演化、对应的异常环流型及其年际变率的模拟性能进行了评估。结果表明,除了NCAR_CAM3模式以外,其余模式均能较好的再现SWWA地区近地层盛行风向季节性反转及副热带高压脊线的季节性跳跃特征。对副热带高压脊线的季节演化特征,虽然大部分模式可以模拟出其季节移动特征,但是对于副热带高压脊线的北跳、南撤时间、到达位置和年内振幅均不能很好模拟。其次,除了NCAR_CAM3,其余模式基本能刻画出与SWAC相联系的异常环流型结构;而对于SWAC的年际变率,基本所有模式均不能较好模拟。整体权衡,GISS_MODEL_E_R在模拟SWAC环流的年际变率方面表现出较其它模式稍好的性能,大致可以模拟出与观测SWAC相似的特征,对SWWA地区的冬季降水显示出了与观测相似的显著影响。

Based on the variability of the southwest Australian circulation （SWAC）, the simulation capabilities of 12 atmospheric general circulation models （AGCMs） provided by IPCC AR4 have been evaluated and compared. The seasonal features, annual cycle, associated circulation anomalies pattern, and interannual variability of the SWAC, as well as the seasonal march of the southwest Western Australia （SWWA） rainfall are analyzed by using the IPCC AMIP models data. Result shows that except the NCAR_CAM3, the else models can capture the basic seasonal features and corresponding circulation anomalous characteristics of the SWAC, but not for the seasonal march of the subtropical high ridge within the SWAC domain and interannual variability of the SWAC. Thus the relevant part of the models should be improved to well simulate the SWWA climate. In a word, the GISS_MODEL E R exhibits a little better performance among the 12 different models, which could generally capture the features of SWAC and shows similar significant impacton the SWWA winter rainfall as in the observation.