北京气候中心大气模式对季节内振荡的模拟

Simulations of the tropical intraseasonal oscillation in the National Climate center’s Atmospheric general model

中文关键词:  国家气候中心，大气模式，季节内振荡，模拟研究

英文关键词:National climate center（NCC）,GCM ,Intraseasonal oscillation ,Simulation study

中文摘要:

      对中国国家气候中心大气模式(NCC_AGCM2.0.1)模拟热带季节内振荡的能力进行了检验。并将检验结果与观测及NCAR CAM3模式的模拟结果进行了比较。中国国家气候中心新一代气候模式(NCC_AGCM2.0.1)是在原中国国家气候中心模式的基础上参考NCAR CAM3经过改进形成的。新模式中引进了一个新的参考大气和参考面气压。因此原模式的预报量中的气温（T）和地面气压（ps）则变为它们对参考大气气温的偏差和对参考面气压的偏差。模式还加入了新的Zhang_Mcfarlane 对流参数化方案，并对其参数计算方法进行调整和改进。此外还对模式边界层处理、雪盖计算等进行了改进。上述模式在实测的月海温作为下边界条件的情况下运行52 a（1949年9月-2001年10月）。然后对运行结果中的季节内振荡的状况进行分析，主要结果如下： NCAR-CAM3模式的模拟热带季节内振荡的能力很差，主要表现在模拟的热带季节内振荡强度很弱；东移波与西移波的强度很接近，而实际观测中是东移波的能量要远大于西移波；季节内振荡的季节变化与空间分布与观测相差很远。 中国国家气候中心大气模式（NCC_AGCM2.0.1）模拟热带季节内振荡的能力有显著的提高。模拟的热带季节内振荡很明显，强度接近于观测结果；模拟东移波的能量要大于西移波，这与观测较为一致；季节内振荡的季节变化与空间分布与观测相差不大。总的来看，NCC2.0.1模式在模拟热带季节内振荡方面比原来的CAM3模式有明显的改进。

英文摘要:

      The simulation ability of NCC(National Climate Center) AGCM(version 2.0.1) to the tropical intraseasonal oscillation (TIO) is examined in this paper. The simulation results is validated against observation and also compared with the NCAR CAM3. The NCC_AGCM2.0.1 is developed based on the original NCC AGCM(version 1) and NCAR CAM3. A new reference atmosphere and reference pressure are introduced to the model. Therefore the original prognostic variable of temperature becomes to the temperature departure to the reference atmoshphere and the surface pressure becomes to its departure. A new Zhang_Mcfarlane convection scheme is incorporated into the model with some modifications. The other modifications include the boundary layer process and snow cover calculation. The models are run for 52 years from 1949 through 2001 under the lower boundary conditions of observed monthly SST. The tropical intraseasonal oscillations from the model output are analyzed. The comparison shows that the NCAR-CAM3 model has poor ability in simulating the tropical intraseasonal oscillation. The strength of the tropical intraseasonal oscillation from the model is very weak; The energy of the eastward moving wave is similar to that of the westward moving wave in the simulation results of CAM3. While in observation the energy of the eastward propagating waves is much larger than that of the westward propagating waves. The seasonal variation and spatial distribution of the TIO produced by CAM3 is much different from the observation. The ability of the NCC AGCM2.0.1 in simulating the TIO has improved very much. There is a obvious intraseasonal oscillation in the NCC’s model. The sthength of the TIO produced by NCC Model is close to the observation. The energy of eastward moving wave is much stronger than that of the westward moving wave. This is close to the observation. There is no big difference in the seasonal variation and spatial distribution between the NCC model and the observation. In general the NCC’s model is better than the CAM3 in the aspect in simulating the TIO.