本研究從IPCC第四期評估報告官方網站挑選了七個時空解析度俱佳的氣候模式，對照NCEP/NCAR重分析資料和CMAP雨量資料兩組全球格點觀測資料，分析模式對亞洲季風的季節和年際變化之模擬。結果顯示模式對於亞洲季風有一定的模擬能力，大部分模式基本上都能模擬出亞洲夏季季風環流和降雨空間分佈的主要型態，但是模式之間的差異度甚大。若把亞洲季風按地理位置分為南亞、東亞、西北太平洋三個次季風區，模式對南亞季風的模擬普遍較佳，西北太平洋季風最差。模式可做出和觀測分析場相當接近的南亞季風區雨量和環流的季節性變化，但是對西北太平洋季風區的雨量和環流氣候的季節性變化均無法準確掌握。比較模式對於三個季風區環流和雨量的模擬能力，發現模式在印度季風區的相關係數明顯高於其他兩個季風區，顯示模式對於南亞季風有比較好的模擬能力，大多數模式在三個季風區中對於風場空間特性的掌握比雨量更好。

This study analyzed the Asian summer monsoon simulated by seven coupled general circulation models (GCMs) participating in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4). The seasonal cycles and interannual variability associated with the Asian monsoon rainfall and low-level circulation are compared with CMAP and NCEP/NCAR Reanalysis data sets for the period of 1979-1999. The models are selected according to the horizontal resolution and the availability of daily precipitation data. When evaluating the model results of Asian summer monsoon, the monsoon system is divided to Indian summer monsoon (ISM), East Asian summer monsoon (EASM), and western North Pacific summer monsoon (WNPSM) three subsystems. The results show that most models can not correctly capture major rainfall areas in Asian summer monsoon systems. The simulation of rainfall and circulation patterns in EASM and WNPSM are considerably poorer than ISM. The ISM can be reasonably simulated by most models in terms of its seasonal cycles and the magnitude of interannual variability. Models cannot capture the beginning and ending months of the major rainy season of WNPSM, this results form the incapability of simulating the low-level convergence over South China Sea and tropical western North Pacific. The circulation features of the three monsoon subsystems are better simulated than precipitation.