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Abstract Accelerated urbanization increases both the frequency and intensity of heatwaves (HW) and urban heat islands (UHIs). An extreme HW event occurred in 2012 summer that caused temperatures of more than 40°C in Chicago, Illinois, USA, which is a highly urbanized city impacted by UHIs. In this study, multiple numerical models, including the High Resolution Land Data Assimilation System (HRLDAS) and Weather Research and Forecasting (WRF) model, were used to simulate the HW and UHI, and their performance was evaluated. In addition, sensitivity testing of three different WRF configurations was done to determine the impact of increasing model complexity in simulating urban meteorology. Model performances were evaluated based on the statistical performance metrics, the application of a multi‐layer urban canopy model (MLUCM) helps WRF to provide the best performance in this study. HW caused rural temperatures to increase by ∼4°C, whereas urban Chicago had lower magnitude increases from the HW (∼2–3°C increases). Nighttime UHI intensity (UHII) ranged from 1.44 to 2.83°C during the study period. Spatiotemporal temperature fields were used to estimate the potential heat‐related exposure and to quantify the Excessive Heat Factor (EHF). The EHF during the HW episode provides a risk map indicating that while urban Chicago had higher heat‐related stress during this event, the rural area also had high risk, especially during nighttime in central Illinois. This study provides a reliable method to estimate spatiotemporal exposures for future studies of heat‐related health impacts.
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This content will become publicly available on November 2, 2026
Investigating the interaction of tropical cyclone-heatwave compound hazards in urban environments
While tropical cyclone (TC) and heatwave (HW) compound hazard extremes are rare in the historical record, they have been recently emerging and are expected to become more frequent under future climate projections. Joint TC-HW hazards can exacerbate heat stress felt by residents, particularly in densely populated urban communities or areas suffering from storm-related power outages. The Princeton Urban Canopy Model (PUCM) has been used to evaluate heatwave conditions in urban environments, but has yet to be used to model joint TC-HW conditions. In this study, we model joint TC-HW hazards by adjusting the surface energy and water budgets of the PUCM to account for TC flood and extreme wind hazards. We investigate joint hazard interactions during Hurricane Laura (2020) using the Weather Research and Forecasting model (WRF) to simulate both Laura's wind field to drive subsequent hydrodynamic modeling of inundation and post-storm atmospheric conditions. The WRF and hydrodynamic modeling results are then used to drive the PUCM to assess the interaction of joint flooding, wind, and heat and their impacts on the city of Lake Charles in Louisiana. Results show that accounting for TC inundation up to a week after landfall can cause over 3°C reductions in daytime heat stress and 1.5°C increases in nighttime heat stress compared to simulations that ignore the presence of flooding. Accounting for defoliation from extreme TC winds can increase maximum nighttime heat stress by more than 4°C.
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- Award ID(s):
- 2103754
- PAR ID:
- 10650853
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Urban Climate
- Volume:
- 64
- Issue:
- C
- ISSN:
- 2212-0955
- Page Range / eLocation ID:
- 102667
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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