DOI: 10.25442/hku.30203347
title: <b><i>Supporting data for thesis titled</i></b> "The Interplay of Tropical Cyclones and Urban Morphology: Compound Impacts on Extreme Heat Dynamics in East Asia"

description: Human-climate-environment interaction is a complex causal relationship between the anthroposphere, the natural atmospheric environment, and vice versa. Yet, the development of megacities and irreversible trends in a changing climate have brought us new hazards through compound extreme weather events in urban society. Tropical cyclones (TCs) occasionally contribute disastrous damage to infrastructure caused by strong winds and surges. When at far distances, the peripheral warming and subsidence flow driven by TCs could 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. Despite the compound impacts of TC-Heat exacerbating numerous socio-environmental risks, the mechanism, strength, and associated impacts of TC-Heat remain unclear. To reveal the interplay between urban morphological variabilities and natural influencers on the promotion of TC-Heat extremes, several research objectives were defined in this thesis to investigate this mystic compound impact. Mixed research methods were adopted to analyse, model and map the spatiotemporal patterns of TC-Heat across scales. The study aims to synthesise the scientific findings and provide mechanistic insights on future heat-resilience and adaptation strategies.The thesis adopts a top-down approach and is divided into three main studies, investigating the TC-Heat mechanism and its impacts, from the continental level down to the regional and ultimately the local community level. In Chapter 4, a zonal analysis of decadal TC activities and their corresponding TC-Heat impacts was studied for the East Asian continent. The WBGT analysis here confirmed the potential for intensifying heat extremes with the presence of TC. The results also indicated that the highly populated regions along the coast, such as Pearl River Delta (PRD), Seoul and part of Japan, are experiencing an amplifying probabilistic TC-Heat risk over the past three decades. In terms of regional and local scales, the relationship between TC-derived intercity and intracity heat dynamics with upwind land-use was elucidated. A multi-layer urban canopy model with WRF (mesoscale meteorological model) was used in Chapters 5 and 6 to re-enact the upwind-downwind advection activities under TC-circulation influence. From the simulation results, upwind land-use was identified as the catalyst for the exacerbation of extreme hot days under peripheral subsidence impacts. From the case study between PRD and Hong Kong, with the concurrent existence of regional and local heat advection driven by TC-circulation, up to 1.8°C increase in temperature could be magnified on top of the temperature extremes (i.e. 36°C) under TC-Heat conditions. An occupant energy usage behavioural model has also been developed in this thesis 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.