Sensitivity of numerical simulations of the East Asian summer monsoon rainfall and circulation to different cumulus parameterization schemes

A 5-level spectral AGCM (ImPKU-SLAGCM) is used to examine the sensitivity o f the simulated results of the summer monsoon rainfall and circulation in E ast Asia to different cumulus parameterization schemes in the climatologica l-mean case and in the cases of weak and strong Asian summer monsoons, resp ectively. The results simulated with the Arakawa-Schubert's(hereafter A-S's ), Kuo's and Manabe's cumulus parameterization schemes show that these simu lated distributions of the summer monsoon rainfall and circulation in East Asia depend strongly on the cumulus parameterization schemes either in the climatological-mean case or in the cases of weak and strong Asian summer mo nsoons. From the simulated results, it might be shown that the Kuo scheme a ppears to be more suitable for the simulation of the summer monsoon rainfal l and circulation in East Asia than the A-S scheme or the Manabe scheme, al though the A-S scheme is somewhat better in the simulations of the tropical rainfall. This might be due to that the Kuo's cumulus parameterization sch eme is able to reflect well the characteristics of rainfall cloud system in the East Asian summer monsoon region, where the rainfall system used to be a mixing of cumulus and stratus.