利奇马台风风场与湍流特征分析  

Wind and turbulence characteristics of typhoon Lekima

作　　者：蔡菊珍 徐集云[1] 邵鑫 彭珍[2] 张宁[2] 张育慧 何月[1] Cai Juzhen;Shao Xin;Peng Zhen;Zhang Ning;Xu Jiyun;Zhang Yuhui;He Yue(Zhejiang Climate Center,Hangzhou,310052,China;School of Atmospheric Sciences,Nanjing University,Nanjing,210023,China)

机构地区：[1]浙江省气候中心,杭州310052 [2]南京大学大气科学学院,南京210023

出　　处：《南京大学学报（自然科学版）》2021年第5期896-903,共8页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(41975006);浙江省自然科学基金(LGF18D050001)。

摘　　要：由于台风的风速大、湍流活跃,台风过境时会对房屋、桥梁等建筑物造成严重危害.利用2019年8月8日至11日利奇马台风过境浙江时的近地层湍流资料,对利奇马台风的风速、风向、攻角、湍流强度、阵风因子、湍流积分尺度、湍流功率谱特征进行了分析.结果表明:(1)在台风前期和大风期,随着台风接近,慈溪观测场附近的风速急剧增大,流场主要为偏东气流;在台风后期,随着台风远离观测场,风速迅速减小,风向逐渐由偏东风转为西南风.(2)在台风前期和大风期,攻角、湍流强度和阵风因子都比较小;而在台风后期,攻角、湍流强度和阵风因子都明显增大,同时湍流积分尺度突然变小,说明了利奇马台风内部流场非常复杂,不同区域会出现不同的中小尺度结构,表现出不同的湍流特征.(3)在台风前期和大风期,惯性子区湍流能谱基本满足-2/3律,而大风期的湍流能谱与-2/3律偏离比较大,同时由于台风内部存在大量的中小尺度系统,在大尺度和湍流尺度涡旋之间,顺风方向的湍流能量贡献仍然很大.The passage of typhoon could be harmful to buildings and bridges due to strong wind and active turbulence in typhoon.This study analyzes wind speed,wind direction,attack angle,turbulence intensity,gust factor,turbulent integral length,and turbulent spectrum of typhoon Lekima using observations collected in Zhejiang province from 8 to 11 August 2019.The results show as following.(1)Wind speed dramatically increases at the early stage and strong wind stage of typhoon,where easterly wind dominants.At the final stage of typhoon,wind speed decreases and wind direction turns to southwest.(2)The attack angle,turbulence intensity,and gust factor are small at the early stage and strong wind stage of typhoon.However,these three parameters increase and the turbulent integral length suddenly decreases at the final stage of typhoon,indicating complex flow field in typhoon Lekima.Meso⁃micro scale structures changes with quadrants in typhoon.(3)The turbulent spectrum nearly follow Kolmogorov's-2/3 law at the early stage and strong wind stage of typhoon,however at the final stage,they do not have such a relationship.For the range between mesoscale and turbulence scale,along⁃wind component contributes largely to the total turbulent energy since a large amount of meso⁃micro scale eddies exist in typhoon.

关 键 词：近地层 攻角 湍流强度 阵风因子 湍流积分尺度 湍流功率谱 利奇马台风 

分 类 号：P404[天文地球—大气科学及气象学]