基于HY-2B散射计的热带气旋定位定强研究

热带气旋灾害是最严重的自然灾害之一，其影响程度主要取决于气旋的中心位置和强度。提高热带气旋中心位置及强度监测水平对于改进热带气旋分析预报精度、减少热带气旋的灾害影响具有重要意义。本文以HY-2B散射计为例，分析了散射计风场散度和旋度的分布特征，发现气旋中心附近风场的散度或旋度具有显著的分布规律，由此提出了一种新的气旋中心定位方法，并与传统的直接定位法进行比较研究。在此基础上，进一步提出了热带气旋风圈大小估计的方法，用于评估气旋的强度。最后，利用台风“范斯高”和“博罗依”的遥感数据对文中的方法进行验证，结果表明，使用新方法定位的气旋中心位置与最佳路径之间的差异小于20 km，散射计17 m/s风圈大小的变化一定程度上反映了气旋的发展规律。

Determination of tropical cyclone location and intensity using HY-2B scatterometer data

Tropical cyclone disaster is one of the most serious natural disasters, and its impact mainly depends on the center location and the intensity. Monitoring the location and the intensity of tropical cyclones is of great significance for improving the accuracy of tropical cyclone forecast and for reducing the impact of tropical cyclone disasters. In this paper, the characteristics of the HY-2B scatterometer wind field, as well as its divergence and curl, are analyzed. It is found that the divergence or curl of the wind field near the cyclone center shows remarkable signatures, such that a new method is proposed to identify the cyclone center, and then the results are compared with the conventional method. Moreover, a method for estimating the size of the tropical cyclone is introduced to evaluate the cyclone intensity. Finally, the remote sensing data of Typhoon Francisco and Typhoon Bualoi are used to verify the proposed methods. The results show that the difference between the cyclone center position determined by the scatterometer and the one of the optimal path is generally less than 20 km. Meanwhile, the determined wind radii correspond well with the development of the tropical cyclone.