GRAPES模式动力框架的长期积分特征  

Characteristics of GRAPES Dynamical Core in Long Term Integration

作　　者：胡江林[1] 沈学顺[2] 张红亮[2] 杨学胜[2] 王盘兴[1] 

机构地区：[1]南京信息工程大学大气科学系,南京210044 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081

出　　处：《应用气象学报》2007年第3期276-284,共9页Journal of Applied Meteorological Science

基　　金：国家"十五"科技攻关课题(2004BA607B01);国家自然科学基金项目(40675062;40505023)共同资助

摘　　要：通过考虑动量表面拖曳并利用牛顿松弛方法将温度松弛到纬向对称的温度场,对GRAPES模式的动力框架进行了长期时间积分试验。通过统计分析其积分结果表明:GRAPES模式的动力框架可以模拟出大气环流的基本特征;随着分辨率的提高,GRAPES模式动力框架的模拟结果显示出收敛的特性;虽然GRAPES模式动力框架采用的是能量不守衡的半隐式半拉格朗日时间积分方案,但长期时间积分试验表明其能量基本保持稳定。这些结果显示使用GRAPES模式动力框架作大气环流和气候研究的大气动力框架是可行的,同时也为进一步改进GRAPES模式动力框架提供了线索和依据。In order to evaluate the characteristics of the dynamical core of GRAPES （Global/Regional Assimilation and PrEdiction System） and to verify whether the GRAPES dynamical core can be taken as a framework of AGCM, the long time integration has been carried out with GRAPES dynamical core followed by the benchmark test similar to the technique introduced by Held and Suarez. The GRAPES has a finite-difference dynamical core with fully compressible, non-hydrostatic framework and semi-implicit and semi-lagrangian （SISL） time integration scheme using latitude and longitude horizontal coordinate as well as following terrain height vertical coordinate. The computational design uses two simple physical processes to represent physics processes in the model during the time integration. The first process is to relax the model variant, potential temperature, to a prescribed potential temperature field which is a function of latitude and height during the model time integration. Following Held and Suarez, the second one is the momentum drag in the lower troposphere to consume the kinetic energy in the model atmosphere. The GRAPES dynamical core runs with 31 levels in vertical direction and 3 horizontal resolutions ： 1.25°, 2.5° and 5.0° latitude or longitude. The benchmark tests integrate for 1460 days under each horizontal resolution and the last 1000 days data are analyzed by discarding the previous 460 day results. The statistic results show that the GRAPES dynamical core can reproduce basic features of atmospheric circulation, including reasonably realistic zonal mean temperature and its eddy variance as well as zonal-mean wind and its eddy variance. A single westerly jet is generated with maximum strength of roughly 28 m/s near 45° latitude in the tropopause. And eddy temperature variance shows two middle latitude maxima, one in the low troposphere and the other above tropopause. The GRAPES dynamical core also shows stability for the energy and momentum as well as vertical wind speed during the long term integr

关 键 词：基准测试 大气环流模式 动力框架 数值试验 

分 类 号：P434[天文地球—大气科学及气象学]