初始场和长波辐射对气候模拟的影响
Impact of Initial Field and Long Wave Radiation on Climate Modeling
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摘要: 对CCM2 (T42L18) 模式运行10次,每次初始状态稍微变化。试验结果表明了CCM2模式对初始场的响应,10次运行长波辐射(LWR)加热率的标准差在全球许多地方和谱的许多尺度上超过10%。相似的结果也可以从云和温度的计算结果中发现。从CCM2算法的10次运行和应用CCM2、MOR和NMC三种不同的LWR算法的3次运行的试验比较中发现,不同LWR算法模式运行之间的变率比没有LWR算法变化的初始场作用大得多。在CCM2模式中,比较应用CCM2、MOR和NMC三种不同的LWR算法的气候模拟,我们发现CCM2和MOR的算法比较接近,而和NMC的差别较大。但三种不同的LWR算法3次运行积分结果的平均值和不同算法间的绝对差值在全球许多地方和不同尺度上的差别都超过10%,远远大于初始场对气候模拟的作用。Abstract: Ten realizations of CCM2 (T42L18) with only slight variations in the initial states have been carried out. The results reveal the response of CCM2 to the initial field, and it is evident that there is substantial variability in the runs, with deviations in many places on the globe and various spectral scales being in excess of 10%. Similar results are found for clouds and temperature. Comparing ten CCM2 algorithm runs with three runs using CCM2, MOR and NMC algorithms, it is evident that the climate simulations for the runs with different algorithms show much larger variability from one another than that for the initial field without changes of LWR algorithms. Comparing the modeling results using the CCM2, MOR and NMC algorithms in the CCM2 model, it can be seen immediately that CCM2 and MOR runs are closer to one another than to the NMC run. Nevertheless, the differences on all charts exceed 10% in many places on the globe, which are far above the impact of the initial field on climate modeling.
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Key words:
- Initial field;
- Long-wave radiation;
- Climate modeling;
- Heating rates
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表 1 CCM2、MOR和NMC三种不同的LWR方案的比较
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[1] Fels S B, Kaplan L D. A test of role of longwave radiative transfer in a general circulation model.J. Atmos. Sci., 1975, 32: 779-789. doi: 10.1175/1520-0469(1975)032<0779:ATOTRO>2.0.CO;2 [2] Ramanathan V, Pitcher E J, Malone R C, et al. The response of a spectral general circulation model to refinements in radiative processes.J. Atmos. Sci., 1983, 40: 605-630. doi: 10.1175/1520-0469(1983)040<0605:TROASG>2.0.CO;2 [3] Luther F M, Ellingson R G, Fouquart Y, et al. Intercomparison of radiation codes in climate models (ICRCCM): Longwave clear-sky results-A workshop summary.Bull. Am. Meteorol. Soc., 1988, 69: 40-48. [4] Ellingson R G, Ellis J, Fels S B. The intercomparison of radiation codes used in climate models: Long wave results.J. Geophys. Res., 1991, 96:8929-8953. doi: 10.1029/90JD01450 [5] 沈元芳, Baer F.全球气候模式对辐射强迫的响应.应用气象学报, 1997, 8(增刊):78-86. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20080615&flag=1 [6] Morcrette J, J. Impact of changes to radiation transfer parameterization plus cloud optical properties in the ECMWF model. Mon.Wea. Rev., 1990, 118: 847-873. doi: 10.1175/1520-0493(1990)118<0847:IOCTTR>2.0.CO;2 [7] Morcrette J, J. Radiation and cloud radiative prpperties in the ECMWF forecasting system. J. Geophys. Res., 1991, 96: 9121-9132. doi: 10.1029/89JD01597 [8] 沈元芳, 伊兰, 陈谊, 等.辐射参数化的变化对模式中期和月预报的影响.应用气象学报, 2002, 13(3):299-311. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20020340&flag=1 [9] 颜宏.关于气候预测与模拟若干问题的思考.应用气象学报, 1997, 8(增刊):6-14. http://www.cnki.com.cn/Article/CJFDTOTAL-YYQX7S1.002.htm [10] Williamson G S. CCM2 Datasets and Circulation Statistics. NCAR/TN-391+STR, 1993. 23-29. [11] Gates W L. AMIP: The atmospheric model intercomparison project. Bull. Amer. Meteor. Soc., 1992, 73: 1962-1970. doi: 10.1175/1520-0477(1992)073<1962:ATAMIP>2.0.CO;2 [12] Williamson D L, Kiehl J T, et al. Description of the NCAR Community Climate Model. NCAR/TN-382+STR, 1993. 46-61. [13] Morcrette J, J, Fouquart Y. On systematic errors in parameterized calculations of longwave radiation transfer. Q.J.R.Meteorol. Soc., 1985, 111: 691-708. doi: 10.1002/qj.49711146903 [14] Schwarzkopf M D, Fels S B. The simplified exchange method revisited: An accurate, rapid method for computation of infrared cooling rates and fluxes. J. Geophys. Res., 1991, 96: 9075-9096. doi: 10.1029/89JD01598