用扩展飓风体积速度处理方法分离台风的环境平均风场  

Separation of the environmental wind and typhoon by extended-hurricane volume velocity processing method

作　　者：朱文剑[1] 赵坤[1] 陈小敏 王明筠[1] 

机构地区：[1]南京大学大气科学学院中尺度灾害性天气教育部重点实验室,南京210093

出　　处：《南京大学学报（自然科学版）》2010年第3期243-253,共11页Journal of Nanjing University（Natural Science）

基　　金：国家重点基础研究发展规划项目(2009CB421502);国家自然科学基金(40975011和40505004);中国气象局大气探测中心"多普勒雷达登陆台风监测预警系统建设"项目(GYHY200706033)

摘　　要：广义速度轨迹显示(generalized velocity track display,GVTD)方法利用单多普勒雷达观测的径向速度,可有效反演台风运动结构特征.然而,该方法无法客观确定台风所在环境风场,因而常造成轴对称环流的反演误差.飓风体积速度处理(hurricane volume velocity processing,HVVP)方法能估计台风的环境平均风,但其需人为设定轴对称切向风廓线系数,并忽略了径向风侧风切变的影响.本研究结合GVTD和HVVP优点,发展一套利用单多普勒雷达观测数据反演环境风的方法(称为extended-HVVP;EHVVP).理想实验采用蓝金涡旋叠加环境平均风得到雷达观测径向风,对此算法进行测试.理想实验结果显示,EHVVP方法能有效且合理的反演理想涡旋的环境平均风,反演的平均风速大小误差在1 ms-1以内,方向误差在6°以内.反演误差随最大切向风半径同涡旋中心——雷达距离的比值和中心定位误差增加.此外,反演误差也受非轴对称切向风影响,误差大小随非对称风速的极大值所在方位角变化.The so-called generalized velocity track display（GVTD） method was used to retrieve the primary circulation structure of typhoon inner core from single Doppler radar observations.However,this method can not objectively resolve the mean wind,thus leading to bias in the estimation of the axisymmetric circulation.Although the hurricane volume velocity processing（HVVP） technique can be used to estimate the mean wind of typhoon,it is of limitations in the following two areas： 1） the inability due to objectively resolve the exponential decrease of the tangential wind speed with increasing the radius,and 2） the inability due to resolve the contribution to the radial confluence from the downwind wind shear of the tangential wind.To accurately separate the mean wind and typhoon from single Doppler radar observations,this study develops a new method,i.e.,the extended-HVVP（EHVVP） method by the hybrid way to combining the advantages of GVTD and HVVP methods.The ideal experiments with the Rankine vortex plus the mean wind have been conducted to verify this method.The results show EHVVP method can resolve the mean-wind accurately with the mean error less than 1 ms-1 in wind speed and 6° in the wind direction.The retrieval errors increase with the ratio of the radius of maximum tangential wind（RMW） to the distance from the radar to the vortex center,and the deviations of the typhoon center location.In addition,the retrieval errors vary with the phase angle of asymmetric peak wind component.

关 键 词：EHVVP方法 台风 环境平均风场 多普勒雷达 

分 类 号：P412.25[天文地球—大气科学及气象学]