路经南海热带气旋迅速加强的年代际变化

本文利用中国气象局热带气旋资料中心最佳路径数据集、美国国家环境预报中心/美国国家大气研究中心大气再分析数据集和国家海洋信息中心的海洋再分析数据集，研究了路经南海热带气旋迅速加强(Rapid Intensification, RI)的年代际变化。在1951–2017年期间，路经南海的热带气旋主要发生在6–12月，其中发生RI的热带气旋集中在7–12月，且RI呈现年代际变化，这种变化和太平洋年代际振荡(Pacific Decadal Oscillation, PDO)显著相关。在正PDO年，RI频数较少且主要分布在菲律宾群岛东部和南海北部；而在负PDO年，RI频数较多且分布在菲律宾群岛东部的大范围区域。路经南海热带气旋RI的年代际变化与PDO对大尺度海洋大气变量的调制有关。回归分析显示热带气旋潜热对路经南海热带气旋RI频数的年代际变化影响最大，而相对湿度的影响相对较小，垂直风切变的影响很小。

Multidecadal variability of rapid intensification of tropical cyclones passing through the South China Sea

Multidecadal variability of rapid intensification of tropical cyclones passing through the South China Sea (SCS) is investigated using the best track data set of tropical cyclones archived at the China Meteorological Administration, the National Center for Atmospheric Research/National Center for Environmental Prediction atmospheric reanalysis data set, and the China Ocean Reanalysis oceanic reanalysis data set from the National Marine Data and Information Service. During 1951?2017, tropical cyclones passing through the SCS are occurred concentratedly from June through December, among which the tropical cyclones with rapid intensification (RI) are concentrated from July through December. RI events have shown multidecadal variability, which is significantly correlated with the Pacific Decadal Oscillation (PDO). In positive PDO years, RI events, with relatively low frequency, mainly distribute in Eastern Philippines and north of the SCS, while in negative PDO years, RI events, with relatively high frequency, mainly distribute in a large area of eastern Philippines. The multidecadal variation of RI of tropical cyclones passing through the SCS is related to large-scale oceanic and atmospheric variables modulated by PDO. Regression analysis shows that tropical cyclone heat potential has the greatest effect on the multidecadal variation of RI, while relative humidity has a relatively small effect and the effect of vertical wind shear is smaller.