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Tropical cyclones (TCs) pose a significant threat in terms of wind-induced damage and storm risk to the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) of China. In this research, annual power dissipation index (PDI) and storm surge and wave destructive potential (SDP) index from June to November were used to estimate the damage caused by the TC events in the buffer zone of the GBA. The regime shifts in 1993 and 2013 were identified through the Bayesian changepoint detection in six TC datasets. The TC-induced damage during 1994–2012 (the low-damage period) was weaker than that in 1977–1993 and 2013–2020 (the high-damage periods). The intensity and size of stronger TCs are the dominant factors responsible for the interdecadal changes in the TC damage. This may be explained by the influences of sea surface temperature (SST), surface latent heat flux and mid-level relative humidity. During high-damage periods, TCs can extract more energy from the ocean, leading to increased TC intensity and larger size. Conversely, during low-damage periods, TCs undergo a decrease in energy intake, resulting in reduced TC power and smaller size. The variations in the SST are relative to the Luzon Strait transport. In addition, the reduction in TC translation speed is unfavorable for the development of TCs in low-damage periods. Further research suggested that mid-level steering flow affects the TC movement velocity. The results offer valuable insights into the variations in the TC-induced damage in the GBA. [ABSTRACT FROM AUTHOR]

This study investigates the interdecadal changes in the intensity of tropical cyclones (TCs) formed within or entered the South China Sea (SCS) in the TC season (June to November) during 1977–2018. Based on change-point detection in five TC datasets, two high-intensity periods [period 1 (P1): 1977–1993; and period 3 (P3): 2006–2018] and a low-intensity period [period 2 (P2): 1994–2002] were identified. Genesis location and vertical moisture advection dominate the interdecadal changes in TC intensity. TC genesis locations in P1 and P3 shift more eastward than in P2. Statistical analysis shows that the farther east the genesis is located, the longer the intensification duration and the higher the intensity the TC can reach. It is also found that environmental factors around the TC tracks are the other reason for the TC intensity. TCs in P2 pass through the region with adverse environmental conditions more frequently. Mid-level relative humidity and vertical motion are key environmental factors for TC intensity. Genesis location is regulated by the Pacific decadal oscillation, the north Indian Ocean SST and the Atlantic multidecadal oscillation. Atmospheric circulations in the tropical Indian Ocean and SCS affect vertical motion. The results provide some helpful insights into the variation of SCS TC intensity. [ABSTRACT FROM AUTHOR]