Characteristics and Diagnosis of the Landfalling Tropical Cyclones in the Guangdong-Hong Kong-Macao Greater Bay Area of China During 1981-2018

This paper applies statistical and synthetic analysis methods to study the characteristics of the three types of tropical cyclone (TC) that landed in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) from 1981 to 2018 and the reasons for the differences of TC-induced wind and precipitation. The results show that there are interdecadal changes in the frequency and intensity of the landfalling TCs in the GBA, with decreased frequency but increased intensity in the 2010s. The TCs that landed in the west of the Pearl River Estuary (PRE) have the most frequency and the strongest intensity during landing, which bring the strongest winds; the TCs that landed in the PRE have the least frequency and the shortest duration after landing, which cause the strongest precipitation; the TCs that landed in the east of the PRE have the relatively longest duration on the land. This study shows that near the center of the TCs that landed in the PRE, there is a weak anomalous cyclonic shear compared with the ones that landed in the west of the PRE. Compared with the TCs that landed in the east of the PRE, it is a confluence area of anomalous north wind and anomalous southwest wind, with better water vapor convergence and dynamic rising conditions, which is conducive to the formation of heavy precipitation. Compared with the TCs that landed in the PRE and in its east, there is a closed positive anomalous center of pressure gradient in the northwest center of the TCs that landed in its west, resulting in higher wind speeds in the west of the PRE. The characteristics of the three types of TCs in the GBA are highly related to TC-induced damage. In the future, the GBA needs to focus on preventing TCs landing in its west. Zhuhai, Jiangmen and Huizhou are key cities to guard against TCs. The results of this study provide foundations for effective management and reduction of TC disaster risks in the future construction of the GBA.     

我国沿海主要省份热带气旋风雨因子危险性分析Ⅱ:年代际变化特征

利用热带气旋最佳路径资料和气象台站观测资料,以及风雨因子危险性模型,分别计算我国沿海主要省份热带气旋风因子危险性、雨因子危险性及总危险性,并对其年代际变化特征进行分析。结果表明:沿海主要省份热带气旋致灾因子危险性随着年代逐渐增大,风因子危险性呈逐年代减弱,而降水因子危险性则逐年代增加;与1970年代相比,热带气旋在2000年代更易带来强降水,但极端风速出现的概率减小,热带气旋活动频数偏少,热带气旋的平均强度略偏强且持续时间偏长;与1970年代相比,2000年代的热带气旋气旋性环流更强烈,其附近低层西南风异常伴随有异常的来自西南向的水汽输送,并产生西南-东北走向的异常水汽辐合带,在异常强烈的垂直运动作用下,更多的水汽将带入高层,有利于降水产生。