23 OCT 2025 (THU) 15:05 - 15:25

The Interplay of Tropical Cyclones and Urban Morphology: Compound Impacts on Extreme Heat Dynamics in East Asia

Mr CHANG Man Hei Jeffrey 

( Supervisor: Prof Nicky Y.F. Lam )

Abstract:

Human-climate-environment interaction is a complex causal relationship between the anthroposphere and the atmospheric environment. Yet, the development of megacities and irreversible trends in a changing climate have brought us new hazards through compound extreme weather events in the urban society. Rainstorm and flooding, wind and storm surge. These are the compound hazards occasionally contributing to the disastrous impacts on building infrastructures and life casualties during the landfall of Tropical cyclones (TCs). When at far distances, the peripheral warming and subsidence flow driven by TCs can also stimulate high temperature extremes, called TC-Heat. Besides, the profound impacts of natural forcings and anthropogenic activities inside a mercurial urban environment can also enhance the TC-Heat severity. To reveal the interplay between urban morphological variabilities and natural influencers on the promotion of TC-Heat extremes, this study adopts a top-down approach to investigate the TC-Heat mechanism and its impacts from continental level to regional and ultimately, local community level.

Zonal analysis of decadal TC activities and their corresponding TC-Heat impacts was studied for the East Asian continent. In terms of regional and local scales, the relationship between TC-derived intercity and intracity heat dynamics with upwind land-use was elucidated with WBGT thermal analysis. A multi-layer urban canopy model with WRF (mesoscale meteorological model) was used to model and re-enact the upwind-downwind advection activities under TC-circulation influence inside a complex urban environment. Occupant energy usage behavioral model has also been developed in this study to assess the heat-energy-carbon emission nexus in relation to TC-associated socio-environmental risks. Cultivated by the interrelationship between TC activities and temperature extremes, this study provided valuable insights into scale-specific heat resilience and adaptation guidelines for the heat-vulnerable population.