【作者】 魏应植； 汤达章； 许健民； 吴陈锋；

【Author】 Wei Ying-zhi1,2, Tang Da-zhang2 Xu Jian-min3, Wu Chen-feng1 (1. Xiamen Meteorological Bureau, Xiamen 361012, Fujian China; 2. Nanjing University of Information Science and Technology, Nanjing 210044, China; 3. National Satellite Meteorological Center, Beijing 100081, China )

【机构】 厦门市气象局； 南京信息工程大学； 国家卫星气象中心；

【摘要】 2004年8月25日,AERE(“艾利”)台风在靠近台湾东北部海域后不同于正常路径,先后发生两次左折,先是西北转偏西,再偏西转西南,这种路径在历史上极为罕见。本文通过AERE台风的雷达观测事实,从单多普勒雷达和双多普勒雷达均发现在台风前进方向的右前方,即西北象限风速极值大于其它象限。进一步证明了AERE台风的风场分布遵循波数为1的非对称性,这种不对称流场可能是导致并维持AERE台风向西南方向移动的重要原因。在我国东南沿海地区,由于单部多普勒雷达不可能同时探测到台风的西北、东北和西南三个象限的风速极值,而双多普勒雷达或多多普勒雷达联合探测台风,则可以同时探测到三个象限的风速极值,根据风速极值可能存在的不对称分布情况来预测台风的路径转折趋势,因此重视双多普勒雷达或多多普勒雷达联合探测对于提高监测预报水平具有重要的意义。本文还探讨了利用多普勒雷达探测结果计算非对称蓝金风场风速的方法。计算结果表明,AERE台风风场不对称结构的方位和距离变化特征相当清楚,与雷达实测结果吻合。其计算简便,对预报业务具有一定的参考价值。更多还原

【Abstract】 On August 25, 2004, after typhoon AERE approached the ocean regions northeastward of Taiwan, its track path turned left twice successively, i.e., turning firstly from northwest to west, and then from west to southwest, which differs from the normal ones and seldom occurs in history. According to the observations of AERE by both single Doppler radar and double Doppler radars, the maximum wind speed always appears in the forward right position of AERE advancing direction, which means the wind speed in the northwest quadrant is the biggest among the whole quadrants. The above results further prove that the wind distributions of AERE follow the asymmetry with one wave number, and it is the unsymmetrical stream field that may play an important role in causing and maintaining the southwestward advancement of AERE. In the coastal regions of the southeast of China, the single Doppler radar can not detect the maximum wind speed of typhoon in the northwest, northeast and southwest quadrants simultaneously, but the double Doppler radars and the multiple Doppler radars can do it. Therefore, when forecasting the turning tendency of typhoon track path based on the possible unsymmetrical distributions of maximum wind speed, the significance for the enhancements of capability in monitoring and forecasting typhoon is great by using the double Doppler radars or multiple Doppler radars. At the same time, methods of calculating unsymmetrical Rankine wind speed with the observations of Doppler radar are discussed. The calculated results show that the variation characteristics of the direction and distance of AERE unsymmetrical wind speed are very clear, and they are identical to the observations of Doppler radars. Additionally, the calculation process is simple, and to some extent, it can works as a reference to the forecast operation.更多还原