台风影响下上海近海风场特性的数值模拟分析  

NUMERICAL SIMULATION AND ANALYSIS OF OFFSHORE WIND FIELD FEATURES IN SHANGHAI UNDER THE INFLUENCE OF TYPHOON

作　　者：徐家良[1] 穆海振[1] 

机构地区：[1]上海市气候中心,上海200030

出　　处：《热带气象学报》2009年第3期281-286,共6页Journal of Tropical Meteorology

摘　　要：选择近年来影响上海最严重的不同路径台风个例,首先利用TAPM数值模式对出现最大风速过程期间,海岸线的风速变化作了数值模拟计算,然后与海岸测风梯度塔的同步观测数据进行对比,在验证了模式计算结果的准确性和可靠性基础上,对台风影响下上海近海区域最大风速的分布特征、不同高度风速变化规律进行分析评估。同时采用海上测风平台的观测数据,对近海海面上的湍流强度作了计算。结果表明:当台风影响上海地区时,上海近海海上的最大风速有较明显的梯度变化;海面上风速随高度变化远比陆上小,各高度层风速如用指数律公式计算,幂指数可取0.09～0.10;海面上的湍流强度亦较小,基本上在0.10以下范围内波动。Based on the route and impact on Shanghai in recent years, cases of typhoons that have the most severe impact but in different routes are selected in this paper. Firstly, the spatial variation of wind speed along the shoreline is numerically simulated for the period of maximum wind speed with the TAPM model. Then the model outputs are compared with synchronous observation data, which have been obtained from seashore wind gradient towers, to verify the accuracy and reliability of the simulations. Lastly, both the distribution characteristics of maximum wind speed and the profile pattern of wind speed in offshore Shanghai are analyzed and assessed, and the turbulence intensity in offshore sea surface is calculated. The results indicate that there is evident gradient change in maximum wind speed in offshore Shanghai when it is under the influence of typhoon, and the wind speed variation with height over sea surface is far smaller than that over land. The suitable power exponent is 0.09-0.10 if the wind speed in different height is calculated with exponential formula. The turbulence intensity over sea surface is also smaller, basically fluctuating within the range of 0.01.

关 键 词：应用气象学 大风特性 数值模式 台风 近海 湍流强度 

分 类 号：P458.124[天文地球—大气科学及气象学]