A regional air-sea coupled model, comprising the Regional Integrated Environment Model System （RIEMS） and the Princeton Ocean Model （POM） was developed to simulate summer climate features over East Asia in 2000. T...A regional air-sea coupled model, comprising the Regional Integrated Environment Model System （RIEMS） and the Princeton Ocean Model （POM） was developed to simulate summer climate features over East Asia in 2000. The sensitivity of the model＇s behavior to the coupling time interval （CTI）, the causes of the sea surface temperature （SST） biases, and the role of air-sea interaction in the simulation of precipitation over China are investigated. Results show that the coupled model can basically produce the spatial pattern of SST, precipitation, and surface air temperature （SAT） with five different CTIs respectively. Also, using a CTI of 3, 6 or 12 hours tended to produce more successful simulations than if using 1 and 24 hours. Further analysis indicates that both a higher and lower coupling frequency result in larger model biases in air-sea heat flux exchanges, which might be responsible for the sensitivity of the coupled model＇s behavior to the CTI. Sensitivity experiments indicate that SST biases between the coupled and uncoupled POM occurring over the China coastal waters were due to the mismatch of the surface heat fluxes produced by the RIEMS with those required by the POM. In the coupled run, the air-sea feedbacks reduced the biases in surface heat fluxes, compared with the uncoupled RIEMS, consequently resulted in changes in thermal contrast over land and sea and led to a precipitation increase over South China and a decrease over North China. These results agree well observations in the summer of 2000.展开更多
运用澳大利亚大气海洋耦合预报模式(Predictive Ocean Atmosphere Model for Australia,POAMA)的输出结果,采用泰勒图与分类统计分析方法,评估了该模式对2003和2004年南海夏季风的爆发和演变进行实时预报的能力。通过对泰勒图的分析发现...运用澳大利亚大气海洋耦合预报模式(Predictive Ocean Atmosphere Model for Australia,POAMA)的输出结果,采用泰勒图与分类统计分析方法,评估了该模式对2003和2004年南海夏季风的爆发和演变进行实时预报的能力。通过对泰勒图的分析发现,随着预报初始时间越来越接近实际的季风爆发时间,模式预报南海夏季风爆发和演变的能力越来越强。当提前1—30d预报南海夏季风时,模式能够很好地预报风场、射出长波辐射OLR(Outgoing Longwave Radiation)和降水场的空间分布,其中对风场的预报最好。通过对季风爆发指数和分类统计的分析,定量分析了模式预报南海夏季风爆发的能力,结果表明该模式对南海夏季风爆发时间有一定的预报能力,其最大预报时限可以提前10—15d左右,这与目前中期预报的上限(2周)是一致的。展开更多
A regional air-sea coupled model based on the regional climate model（RegCM3） and the regional oceanic model POM（Princeton Ocean Model） is developed and a series of experiments are performed to verify the ability o...A regional air-sea coupled model based on the regional climate model（RegCM3） and the regional oceanic model POM（Princeton Ocean Model） is developed and a series of experiments are performed to verify the ability of the coupled model in simulating the summer precipitation over China from 1963 to 2002.The results show that the space correlation coefficients between the GISST（Global Ice and Sea Surface Temperature） data and the simulated SST by RegCM3-POM exceed 0.9.Compared with the uncoupled experiments,the coupled model RegCM3-POM has a better performance in simulating the mean summer（June to August） precipitation over China,and the distribution of the rainband in the coupled model is more accurate.The improvement of the rainfall simulation is significant over the Yangtze River Valley and in South China.The rainbelt intraseasonal evolution over eastern China in summer indicates that the simulation ability of RegCM3-POM is improved in comparison with the uncoupled model.The interannual summer rainfall variation over eastern China simulated by RegCM3-POM is in accordance with observation,while the spatial pattern of the interannual summer rainfall variation in the uncoupled model is inaccurate.The simulated correlation coefficient between the summer rainfall in the uncoupled model RegCM3 and observation is 0.30 over the Yangtze River Valley and 0.29 in South China.The coefficient between the rainfall in the coupled RegCM3-POM and observation is 0.48 over the Yangtze River Valley and 0.61 in South China.The RegCM3-POM has successfully simulated the correlation coefficients between summer rainfall in the Yangtze River Valley and SST anomalies of the Bay of Bengal,South China Sea,and the Kuroshio area,whereas the uncoupled model RegCM3 fails to reproduce this relationship.The study further shows that the monsoon circulation and the path of the moisture transport flux simulated by RegCM3-POM are in good agreement with the NCEP/NCAR data.展开更多
基金supported by the National Basic Research Program under Grand No.2006CB400506
文摘A regional air-sea coupled model, comprising the Regional Integrated Environment Model System （RIEMS） and the Princeton Ocean Model （POM） was developed to simulate summer climate features over East Asia in 2000. The sensitivity of the model＇s behavior to the coupling time interval （CTI）, the causes of the sea surface temperature （SST） biases, and the role of air-sea interaction in the simulation of precipitation over China are investigated. Results show that the coupled model can basically produce the spatial pattern of SST, precipitation, and surface air temperature （SAT） with five different CTIs respectively. Also, using a CTI of 3, 6 or 12 hours tended to produce more successful simulations than if using 1 and 24 hours. Further analysis indicates that both a higher and lower coupling frequency result in larger model biases in air-sea heat flux exchanges, which might be responsible for the sensitivity of the coupled model＇s behavior to the CTI. Sensitivity experiments indicate that SST biases between the coupled and uncoupled POM occurring over the China coastal waters were due to the mismatch of the surface heat fluxes produced by the RIEMS with those required by the POM. In the coupled run, the air-sea feedbacks reduced the biases in surface heat fluxes, compared with the uncoupled RIEMS, consequently resulted in changes in thermal contrast over land and sea and led to a precipitation increase over South China and a decrease over North China. These results agree well observations in the summer of 2000.
文摘运用澳大利亚大气海洋耦合预报模式(Predictive Ocean Atmosphere Model for Australia,POAMA)的输出结果,采用泰勒图与分类统计分析方法,评估了该模式对2003和2004年南海夏季风的爆发和演变进行实时预报的能力。通过对泰勒图的分析发现,随着预报初始时间越来越接近实际的季风爆发时间,模式预报南海夏季风爆发和演变的能力越来越强。当提前1—30d预报南海夏季风时,模式能够很好地预报风场、射出长波辐射OLR(Outgoing Longwave Radiation)和降水场的空间分布,其中对风场的预报最好。通过对季风爆发指数和分类统计的分析,定量分析了模式预报南海夏季风爆发的能力,结果表明该模式对南海夏季风爆发时间有一定的预报能力,其最大预报时限可以提前10—15d左右,这与目前中期预报的上限(2周)是一致的。
基金Supported by the National Natural Science Foundation of China under Grant No. 40805047
文摘A regional air-sea coupled model based on the regional climate model（RegCM3） and the regional oceanic model POM（Princeton Ocean Model） is developed and a series of experiments are performed to verify the ability of the coupled model in simulating the summer precipitation over China from 1963 to 2002.The results show that the space correlation coefficients between the GISST（Global Ice and Sea Surface Temperature） data and the simulated SST by RegCM3-POM exceed 0.9.Compared with the uncoupled experiments,the coupled model RegCM3-POM has a better performance in simulating the mean summer（June to August） precipitation over China,and the distribution of the rainband in the coupled model is more accurate.The improvement of the rainfall simulation is significant over the Yangtze River Valley and in South China.The rainbelt intraseasonal evolution over eastern China in summer indicates that the simulation ability of RegCM3-POM is improved in comparison with the uncoupled model.The interannual summer rainfall variation over eastern China simulated by RegCM3-POM is in accordance with observation,while the spatial pattern of the interannual summer rainfall variation in the uncoupled model is inaccurate.The simulated correlation coefficient between the summer rainfall in the uncoupled model RegCM3 and observation is 0.30 over the Yangtze River Valley and 0.29 in South China.The coefficient between the rainfall in the coupled RegCM3-POM and observation is 0.48 over the Yangtze River Valley and 0.61 in South China.The RegCM3-POM has successfully simulated the correlation coefficients between summer rainfall in the Yangtze River Valley and SST anomalies of the Bay of Bengal,South China Sea,and the Kuroshio area,whereas the uncoupled model RegCM3 fails to reproduce this relationship.The study further shows that the monsoon circulation and the path of the moisture transport flux simulated by RegCM3-POM are in good agreement with the NCEP/NCAR data.
