太平洋经向模态对西北太平洋热带气旋影响的数值模拟研究  

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

作　　者：黄勇[1] 李崇银[1,2] 王颖 

机构地区：[1]解放军理工大学气象学院,江苏南京211101 [2]中国科学院大气物理研究所,北京100029 [3]总参气象水文空间天气总站,北京100081

出　　处：《热带气象学报》2011年第4期433-441,共9页Journal of Tropical Meteorology

基　　金：国家重点基础研究发展计划"973"项目(2007CB411805);国家自然科学基金(U0833602);解放军理工大学气象学院博士(后)科研启动基金共同资助

摘　　要：在分析研究太平洋海气耦合经向模(Pacific Meridional Mode——PMM)和西北太平洋生成热带气旋频数变化关系的基础上,利用NCAR的大气环流模式CAM3模拟研究了太平洋海气耦合经向模态对西北太平洋生成热带气旋的影响。结果表明,海气耦合的经向模态通过影响热带气旋生成的大尺度环境从而影响热带气旋的频数和强度。在模式中当增加了PMM的海温强迫后,纬向风切变变小,对流层中低层相对湿度变大,热带西太平洋对流层低层出现西风异常,在西北太平洋地区形成一个异常的气旋性环流,并且匹配有较大的正涡度异常;对流层高层出现赤道东风异常和一个与低层气旋性环流相匹配的反气旋性环流,有利于对流活动的发展,从而有利于热带气旋的生成和发展。在增加了PMM的海温强迫的试验中,热带气旋中心的海平面最低气压降低,850 hPa中心附近最大切向风速增加,气旋中高层的暖心强度增强。热带气旋强度总体增加。数值模拟结果与资料分析相互映证,揭示了太平洋经向模态对西北太平洋热带气旋有重要影响。Based on the analyses of relationship between Pacific Meridional Mode（PMM） and frequency of Tropical Cyclones activity over the Western North Pacific, the impacts of the PMM on tropical cyclones activity over the Western North Pacific is studied by using numerical simulation with a AGCM（CAM3） of NCAR. The result shows the PMM impacts the large-scale environment of tropical cyclones generating, thus affecting the frequency and strength of tropical cyclones. The numerical simulations using the NCAR CAM3 indicate that the sensitivity test adding the forcing of SST of PMM coincide with the decreased magnitude of the vertical zonal wind shear, larger proportion of relative humidity, anomalous westerly wind at low level and anomalous easterly wind at high level, matchs the anomalous cyclonic circulation at low level and anomalous anti-cyclonic circulation at high level over tropical western pacific. Thus PMM provides favorable environment for the typhoon genesis. Tropical cyclones in the sensitivity test have higher strength. It has lower sea surface pressure of the center, stronger tangential wind of 850 hPa and intensity of warm core at high level. In this paper, the simulation results are similar with that in the data analyses, the important impact of the PMM on tropical cyclones activity over the Western North Pacific has been exposed practically.

关 键 词：热带气旋 太平洋经向模 大气环流模式 

分 类 号：P444[天文地球—大气科学及气象学]