中文摘要：

基于中国科学院大气物理所大气环流模式IAP AGCM4.0总共30年（1979~2008年）的AMIP（大气环流模式比较计划）数值模拟试验结果,评估了模式对东亚高空副热带西风急流的模拟能力,分析了模式模拟偏差的可能原因,以及不同对流参数化方案对模拟结果的影响。结果表明,IAP AGCM4.0可以较好地模拟出东亚高空副热带西风急流冬季和夏季的空间结构及其季节变化特征;与JRA-25再分析资料相比,模式模拟的急流强度总体偏弱;就急流位置而言,模式模拟的急流位置冬季略偏南,夏季则相对偏北;模式可以较好地模拟出夏季西风急流的季节内演变特征,包括夏季西风急流位置逐月北跳的特征,只是模式模拟的逐月西风急流位置仍偏北。夏季200 h Pa纬向风EOF分解结果表明,模式模拟和再分析资料的EOF第一模态空间型态较为接近,均反映了西风急流的年际变化特征,但两者的时间系数相关较小,表明模式对西风急流南北位置年际变化的模拟偏差较大。针对模式模拟的地表感热通量及对流层中上层经向温度差（MTD）的分析结果表明,模式对阿拉伯半岛东南部、阿拉伯海西北部及印度北部的地表感热通量的模拟存在偏差,影响到对流层中高层温度场、高度场的模拟,使得IAP AGCM4.0模拟的MTD强度较再分析资料相对偏弱,MTD变化最大的区域位置相对偏北,且模式模拟的MTD年际变化与再分析资料相比也有较大偏差,从而造成模式对西风急流模拟的偏差。此外,不同积云对流参数化方案也可影响对流层中上层经向温度差的模拟,进而影响模式对东亚高空副热带西风急流的模拟。

英文摘要：

The performance of IAP Atmospheric General Circulation Model Version 4（IAP AGCM4.0） in reproducing the observed features of the East Asian Subtropical Westerly Jet（EASWJ） is examined by analyzing the differences between model simulations and JRA-25 reanalysis data during 1979–2008, the possible reasons for the bias in model performance are analyzed, and the impact of convective parameterization schemes in the model simulations has been further investigated. The results show that the model can reproduce the climatological characteristics of the EASWJ reasonably well, including the spatial structure and the seasonal meridional displacement. However, the model also shows deficiencies in simulating the intensity and location of the EASWJ, with weaker magnitude in both wintertime and summertime, and the model simulated position of the EASWJ is located southward during wintertime and northward during summertime when compared with observations. Analysis of the results demonstrates that IAP AGCM4.0 can capture the seasonal evolution of the EASWJ well, including the northward jump during summer months. Based on Empirical Orthogonal Function（EOF） decomposition of the zonal wind at 200 h Pa, both for the observation and model simulation, it is found that IAP AGCM4.0 can reproduce well the spatial structure of the first leading mode from the observation; however, the model fails to capture the interannual variation of the meridional displacement of the EASWJ. Based on the analysis of surface sensible heat fluxes and mid-upper troposphere Meridional Temperature Difference（MTD）, it is found that the model＇s biases in terms of the simulated surface sensible heat fluxes in the southeastern Arabian Peninsula, northwestern Arabian Sea and northern India cause a weaker intensity and northward shift of MTD. The deficiency of IAP AGCM4.0 in reproducing the interannual variation of MTD leads to the biases in the simulation of the EASWJ. Furthermore, different convective parameterization schemes can influence the si