利用实时多普勒天气雷达、边界层风廓线雷达和自动站资料对超强台风"威马逊"第4次登陆广西沿海时台风结构的演变特征进行研究,结果表明:台风眼区气压呈"漏斗"形变化,具有气压低、风速弱、空气干而暖的特征;登陆过程中眼区保持圆形,半径约为30km,是典型强台风结构;天气雷达径向速度大风区具有非对称性,右象限大于左象限;风廓线雷达水平风场能够精确、直观地描述台风不同部位经过测站时的垂直结构特征,从低层到高层风向先后经历了"东北风—东风—东南风—南风"的转变过程,风速整体上呈现随高度先增大后减小的特点,其垂直速度和大气折射率结构常数(C2n)能够很好地反映台风的结构及其云和气流的变化特征;两种雷达风场产品的风向一致,但是VWP产品的风速比风廓线雷达的要小,VWP产品出现无效数据时,可以用风廓线雷达产品作为补充。
Using the real-time Doppler weather radar,boundary layer wind profiler radar,and automatic weather station data,the characteristic structure evolution in the 4th landing of super-typhoon Ramasun on the Guangxi coastal is studied.The results show that the typhoon eye area had characteristics of low atmospheric pressure,weak wind speed,dry and warm air,in which atmospheric pressure showed funnelshaped changes;the typhoon eye area maintained a round shape during typhoon landing,with a radius of30 km,a typical strong typhoon structure.In addition,the large value area of the radial velocity in radar exhibited an asymmetrical feature with the right quadrant larger than the left quadrant.The error of surface measurements is only 5.4 m/s;the horizontal wind field of wind profiler radar can reflect the vertical structure accurately and intuitively in different parts of the typhoon. Wind direction had experienced anortheast-east-southeast-south"change process,and the overall characteristics of wind speed increased first and then decreased.Moreover,the vertical speed,atmospheric refractive index,structure constant(C2n)can well reflect the variation of typhoon structure,typhoon clouds and airflow;wind direction was consistent in two types of weather radar wind field products,but in VWP products wind speed was smaller than that from wind profiler radar.When there are invalid data in VWP products,wind profiler radar products can be used as complementary.