Tropical cyclones (TCs) are a major dynamic factor affecting the construction and safety of harbors, waterways, coasts, and marine engineering, and have always been a hot topic in estuarine and coastal dynamics research. Due to the lack of effective observational means for the spatial distribution of TCs, real measurements are sparse, and it’s difficult to capture wave height extremes, leaving the study of global typhoon wave trend changes largely unexplored.
The team, in collaboration with researchers from the University of Reading and Imperial College London, has made a significant advancement in this field. Based on the comprehensive validation of the ERA5 reanalysis wave data with the latest buoy and satellite observations, they defined a TCs wave height threshold to extract the distribution characteristics of TCs waves in the global wave field. They analyzed the trends in global wave height extremes, impact areas, and cumulative wave energy caused by typhoons from 1979 to 2022 and derived formulas for calculating the contribution rates of cumulative wave energy. The study found that over the past 44 years, the extreme wave heights caused by global TCs have significantly increased by 0.32%/a, the rate of expansion in affected areas by 0.57%/a, and the rate of increase in cumulative wave energy by 0.9%/a. The increase rate of global TCs cumulative wave energy is three times the growth rate of wave heights, primarily driven by the expansion of the typhoon-affected areas. The trend of TCs waves varies significantly across different global seas. For the Northwest Pacific, the rates of increase in extreme wave heights and affected areas are faster than the global average, at 0.41%/a and 0.69%/a, respectively. However, the trend in the increase of cumulative wave energy is not significant, due to the reduction in the average annual duration of TCs affecting the Northwest Pacific.
The research paper, “Global increase in tropical cyclone ocean surface waves,” completed by Associate Professor Jian Shi, Professor Jinhai Zheng, Professor Chi Zhang, Professor Aifeng Tao, Professor Wei Zhang, Senior Research Fellow Xiangbo Feng from the University of Reading, Professor Kevin I. Hodges, and Professor Ralf Toumi from Imperial College London, was published in the international academic journal “Nature Communications”
(https://www.nature.com/articles/s41467-023-43532-4). The research was supported by the National Key R&D Program Major Project for Natural Disaster Defense and Public Safety Ocean Special Project (2023YFC3007900).