土壤湿度对东亚夏季气候潜在可预报性影响的数值模拟  

Numerical simulation of effect of soil moisture variability on potential predictability of summer climate over East Asia

作　　者：李忠贤[1] 陈海山[1] 倪东鸿[1] 曾刚[1] 

机构地区：[1]南京信息工程大学气象灾害省部共建教育部重点实验室,江苏南京210044

出　　处：《大气科学学报》2012年第4期423-430,共8页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金资助项目(40905045);江苏省"333高层次人才培养工程"项目;江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：利用全球大气环流模式NCAR CAM3进行了在给定的观测海温条件下的22a(1979—2000年)5—8月的2组集合试验。运用方差分析方法,分析了在气候态和年际变化的表层土壤湿度情况下,CAM3模式模拟的东亚夏季气候潜在可预报性及其差异。结果表明:在给定的观测海温条件下,采用气候态的土壤湿度时,CAM3模式模拟的东亚夏季气候的潜在可预报性偏低;而采用年际变化的土壤湿度时,模拟的夏季气候潜在可预报性有所提高,尤其是在中国西北地区;后者模拟的中国西北地区夏季降水和气温的潜在可预报性比前者的模拟结果提高0.1以上。其原因可能是:采用年际变化的土壤湿度时,模式可以更好地模拟出中国西北地区的地表蒸发量和湍流热通量的年际变化,进而使得模式对该地区夏季气候的预报技巧得到提高。Two ensemble simulations for 22 boreal-summer seasons （1979-2000） are conducted by the Community Atmosphere Model version 3 （CAM3） with the specified observed sea surface temperature （SST）. Impacts of surface soil moisture（SSM） on the simulation of potential predictability of East Asi- an summer climate are investigated by the model with interannually varying SSM（ISSM） and climato- logical SSM（ CSSM）, respectively, based on the variance analysis method. Results show that, under the specified observed SST, the potential predictability of East Asian summer climate simulated by the CAM3 with ISSM is better than that with CSSM over East Asia, especially over Northwest China. The potential predictability of summer precipitation and air temperature over Northwest China from ISSM simulations is 0. 1 higher than that from CSSM simulations. A possible mechanism of influence of soil moisture on potential predictability of summer climate in Northwest China is proposed. The interannnal variability of ground evaporation and surface turbulent heat flux can be simulated by CAM3 with ISSM better than with CSSM in Northwest China, leading to the model forecast skill of the summer climate improved by the model with ISSM.

关 键 词：潜在可预报性 夏季气候 土壤湿度 数值模拟 

分 类 号：P456.7[天文地球—大气科学及气象学]