基于引潮力的西北太平洋热带气旋特征研究

利用中国气象局提供的西北太平洋台风最佳路径数据集、欧洲中期天气预报中心（ECMWF）的ERA5再分析资料、美国国家航空航天局（NASA）的HORIZONS系统天文资料，采用统计学方法，分析了1949—2019年西北太平洋生成的热带气旋路径上各节点所受引潮力，并诊断引潮力与大气环流之间的关系。结果表明：1）向上垂直引潮力越大，热带气旋生成数越多、增强速度越快，同时向西移速增大。水平引潮力方位角与热带气旋前进方向接近时，垂直引潮力增强的效果更明显。2）在西北太平洋热带气旋活跃期（7—10月），向上的垂直引潮力有利于大气的上升运动，导致对流层中层（高层）辐合（辐散），形成有利于热带气旋发展的环流配置结构。

Characteristics of tropical cyclone on Northwest Pacific based on tidal force

Using the optimum path dataset of typhoons in the Northwest Pacific provided by China Meteorological Administration, the ERA5 reanalysis data of the European Centre for Medium-Range Weather Forecasts (ECMWF) and the astronomical data of the HORIZONS system of NASA, the tidal force on each node of the tropical cyclone path generated in the Northwest Pacific from 1949 to 2019 was analyzed by statistical method, and the relationship between tidal force and atmospheric circulation is diagnosed.The results show that:1) When the upward vertical tidal force was greater, the number of tropical cyclones was more, the speed of strengthening was faster, and the westward moving speed of tropical cyclones also increased. When the azimuth of the horizontal tidal force was close to the forward movement direction of the tropical cyclone, the effect of the vertical tidal force enhancement was more obvious. 2) During the active period of tropical cyclones in the Northwest Pacific (July to October), the upward vertical tidal force is conducive to the upward movement of air masses, leading to convergence (divergence) in the middle (upper) troposphere, and forming a circulation configuration that was favourable to the development of tropical cyclones.