Version 1
: Received: 5 April 2024 / Approved: 7 April 2024 / Online: 8 April 2024 (16:41:06 CEST)
How to cite:
Chan, P.; Lam, C.; Hui, T.; Gao, Z.; Fu, H.; Sun, C.; Su, H. Case Studies of the Impact of Sea Temperature and Salinity on the Strength of Tropical Cyclones over the Western North Pacific and the South China Sea. Preprints2024, 2024040477. https://doi.org/10.20944/preprints202404.0477.v1
Chan, P.; Lam, C.; Hui, T.; Gao, Z.; Fu, H.; Sun, C.; Su, H. Case Studies of the Impact of Sea Temperature and Salinity on the Strength of Tropical Cyclones over the Western North Pacific and the South China Sea. Preprints 2024, 2024040477. https://doi.org/10.20944/preprints202404.0477.v1
Chan, P.; Lam, C.; Hui, T.; Gao, Z.; Fu, H.; Sun, C.; Su, H. Case Studies of the Impact of Sea Temperature and Salinity on the Strength of Tropical Cyclones over the Western North Pacific and the South China Sea. Preprints2024, 2024040477. https://doi.org/10.20944/preprints202404.0477.v1
APA Style
Chan, P., Lam, C., Hui, T., Gao, Z., Fu, H., Sun, C., & Su, H. (2024). Case Studies of the Impact of Sea Temperature and Salinity on the Strength of Tropical Cyclones over the Western North Pacific and the South China Sea. Preprints. https://doi.org/10.20944/preprints202404.0477.v1
Chicago/Turabian Style
Chan, P., C.J. Sun and H. Su. 2024 "Case Studies of the Impact of Sea Temperature and Salinity on the Strength of Tropical Cyclones over the Western North Pacific and the South China Sea" Preprints. https://doi.org/10.20944/preprints202404.0477.v1
Abstract
With increasing air and sea temperatures, the thermodynamic environments over the oceans become more favourable for the development of intense tropical cyclones (TCs) with rapid intensification (RI). In fact, the number of TCs undergoing RI is rising (Zhao, et al., 2018; Bhatia, et al., 2019; Song, et al., 2020; Hong & Wu, 2021; Liu, et al., 2022). RI over coastal sea areas before landfalling is particularly impactful and threatening to coastal lives and properties. There have been studies showing that offshore areas within 400 km of the coastline have experienced a significant increase in RI events with the count tripling from 1980 to 2020 (Li et al., 2023). The south China coastal region consists of highly densely populated cities especially the Pearl River Delta (PRD) region. Intense TCs maintaining its strength or RI of TCs close to the coastal region presents substantial forecasting challenges. This study investigates the effect of sea surface and subsurface temperature and salinity on the intensification of five TCs, namely Super Typhoons Hato in 2017 and Mangkhut in 2018, Typhoon Talim, Super Typhoon Saola and Severe Typhoon Koinu in 2023, which significantly affected the south China coastal region and triggered high TC warning signals in Hong Kong. The analysis utilized the Hong Kong Observatory (HKO) TC track and intensity data, along with the sea temperature and salinity profiles generated using the China Ocean ReAnalysis version 2 (CORA2) of the National Marine Data and Information Service (NMDIS) of China. While high sea surface temperature (SST) of 30°C or above, low surface sea surface salinity (SSS) of 34 psu or below, and strong salinity stratification of at least 0.8 psu per 100 m depth may offer useful hints for predicting RI, they are part of a broader set of contributing factors. This study represents the initial documentation of sub-surface salinity's impact on intense TCs over the South China Sea (SCS) in recent years and will encourage further research to refine forecasting RI of TCs before making landfall near PRD taking into account the effect of freshwater from the Pearl River.
Environmental and Earth Sciences, Atmospheric Science and Meteorology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
