Urban modeling in support of characterizing extreme heat vulnerability

Extreme heat is a leading cause of weather-related human mortality in the United States and the frequency and severity of heat waves is projected to increase in the 21st century. The System for Integrated Modeling of Metropolitan Extreme Heat Risk (SIMMER) is a NASA-funded project aimed at characterizing and addressing extreme heat risk via an interdisciplinary approach. Through SIMMER, we hope to advance methodologies for assessing current and future urban vulnerabilities from heat waves through the refinement and integration of physical and social science models, and to build local capacity for heat hazard mitigation and climate change adaptation in the public health sector. SIMMER focuses on two cities that are culturally and morphologically different, but both are vulnerable to extreme heat: Houston and Toronto. We will present results from the meteorological and land surface modeling components of SIMMER, for which we have performed high-resolution (0.5-1 km) simulations over both cities. We will focus on a series of sensitivity simulations that explore the degree of model performance that is gained by increasing the complexity of the representation of urban morphology in a land surface model. A companion talk will demonstrate how the modeling results are being integrated with socio-economic data to characterize differential vulnerability to heat waves within Houston.