NUMERICAL SIMULATIONS OF THE PACIFIC MERIDIONAL MODE IMPACTS ON TROPICAL CYCLONES ACTIVITY OVER THE WESTERN NORTH PACIFIC  

作　　者：黄勇 李崇银 王颖 

机构地区：[1]Meteorological,Hydrographic and Spatial Weather General Station of General Staff [2]Institute of Meteorology,PLA University of Science and Technology [3]LASG,Institute of Atmospheric Physics,Chinese Academy of Sciences

出　　处：《Journal of Tropical Meteorology》2012年第4期512-520,共9页热带气象学报（英文版）

基　　金：National Program on Key Basic Research Project (2007CB411805);National Natural Science Foundation of China (U0833602);Initial Fund for Scientific Research for Post-Graduates in Institute of Meteorology,PLA University of Science and Technology

摘　　要：Based on analyses of the relationship between Pacific Meridional Mode (PMM) and number of tropical cyclones (TCs) activity over the western North Pacific, the impacts of the PMM on Tc activity over the western North Pacific are studied using numerical simulations with an Atmospheric General Circulation Model (CAM3) of National Center for Atmospheric Research (of USA). The result shows that the PMM has impacts on the large-scale generating environment of TCs, thus affecting their number and strength. The numerical simulations using the NCAR CAM3 indicate that with the inclusion of the forcing from sea surface temperature (SST) of the PMM, there appears a decreased magnitude of the vertical zonal wind shear, large proportion of relative humidity, anomalous westerly wind at low levels and anomalous easterly wind at high levels, in association with anomalous cyclonic circulation at low levels and anomalous anti-cyclonic circulation at high levels over the tropical western Pacific. Thus, the PMM provides favorable environment for the typhoon genesis. In the sensitivity experiment, TCs have larger strength, lower SST at the center, stronger tangential wind at 850 hPa and intensified warm cores at high levels. In this paper, the simulation results are similar to that in the data analyses, which reveals the important impact of the PMM on TC activity over the western North Pacific.Based on analyses of the relationship between Pacific Meridional Mode （PMM） and number of tropical cyclones （TCs） activity over the western North Pacific, the impacts of the PMM on Tc activity over the western North Pacific are studied using numerical simulations with an Atmospheric General Circulation Model （CAM3） of National Center for Atmospheric Research （of USA）. The result shows that the PMM has impacts on the large-scale generating environment of TCs, thus affecting their number and strength. The numerical simulations using the NCAR CAM3 indicate that with the inclusion of the forcing from sea surface temperature （SST） of the PMM, there appears a decreased magnitude of the vertical zonal wind shear, large proportion of relative humidity, anomalous westerly wind at low levels and anomalous easterly wind at high levels, in association with anomalous cyclonic circulation at low levels and anomalous anti-cyclonic circulation at high levels over the tropical western Pacific. Thus, the PMM provides favorable environment for the typhoon genesis. In the sensitivity experiment, TCs have larger strength, lower SST at the center, stronger tangential wind at 850 hPa and intensified warm cores at high levels. In this paper, the simulation results are similar to that in the data analyses, which reveals the important impact of the PMM on TC activity over the western North Pacific.

关 键 词：tropical cyclones Pacific Meridional Mode atmosphere general circulation 

分 类 号：P444[天文地球—大气科学及气象学]