A model of the sea–land transition of the mean wind profile in the tropical cyclone boundary layer considering climate changes
This study presents and utilizes an integrated semiempirical methodology to estimate a sea–land transition wind profile inside the tropical cyclone boundary layer (TCBL) that considers the impacts of climate change. The TCBL connecting the underlying terrain and the upper atmosphere plays a crucial role in the overall dynamics of a tropical cyclone system. When tropical cyclones approach the coastline, the wind field inside the TCBL makes a sea–land transition to impact both onshore and offshore structures. So better understanding of the wind field inside the TCBL in the sea–land transition zone is of great importance.
The wind profiles calculated based on the Monte-Carlo simulation results reveal that, under the influences of the most severe climate change scenario, slightly higher and significantly lower wind speeds are found at altitudes above and below 400 m, respectively, compared to the wind speeds recommended in the Hong Kong Wind Code of Practice. Such findings imply that the wind profile model currently adopted by the Hong Kong authorities in assessing the safety of low- to high-rise buildings may be unnecessarily over-conservative under the influence of climate change. On the other hand, the coded wind loads on super-tall buildings slightly underestimate the typhoon impacts under the severe climate change conditions anticipated for coastal southern China.