Urban Form and Hydrometeorology

This project will build on the observational evidence in the rich history of NASA data sets, but reach beyond the empirical to reveal the causal chain linking urbanization to hydrometeorological risk through controlled numerical experiments with state-of-the-art quantitative models. The overarching goal of this project is to develop a predictive understanding of how critical causative measures of urban form, conditioned on the regional climate context, act to spatially concentrate and organize heat and precipitation risk to urban populations and infrastructure. (Co-PI, NASA-IDS 2020-2023)


Urban Green Infrastructure and Microclimates

The overarching goal of the project is to elucidate how urban green infrastructures (UGIs) impact the interactions between urban thermal environment and air pollution across multiple spatial scales. Secondly, we are motivated to develop a new method for evaluating the design strategies of UGI by considering the human health implications of heat stress and air pollution combined. (PI, NSF-CBET 2020-2023)

Heavy Aspherical Particles in the Atmospheric Boundary Layer

cHeavy aspherical particles such as microplastics have been found to undergo long-range atmospheric transport. The overarching research question of the project is: given the state-space of microplastic particles (MPs) at emission locations, how does the urban surface configuration and mesoscale forcing interact to shape the probability of airborne MP escape from urban landscapes? The urban building/street configurations to be explored here are derived from a suite of idealized morphological parameters. This approach shares commonalities with current urban land surface representation in regional and global scale weather and climate models. The flow in the atmospheric

boundary layer (ABL) within and above urban surfaces is assumed to be near-neutral forced by synoptic-scale weather

conditions. (PI, NSF-AGS 2020-2023)

Multi-Scalar Transport in Canopy Flows

More than half of the global population live in urban areas, which nontrivially modify the atmosphere through two broad pathways: urban form (i.e. changes in surface properties) and urban function (i.e. anthropogenic activities emitting heat and mass). These two pathways occur via turbulent exchanges of momentum, energy and mass in the atmospheric boundary layer and carry ‘distinct fingerprints’ of a city’s form and function. For increasingly fine-scale climate and numerical weather prediction (NWP) models, it is a persistent challenge to reflect these ‘distinct fingerprints’ of different cities across the world, yet in a manner that is generalizable and computationally tractable. Due to incomplete understanding of multi-scalar transport, whether different scalars of anthropogenic origins obey similarity relations in the urban surface layer remains unclear. This is also one of the key stumbling blocks to generalize urban land-atmosphere exchanges for multiple scalars. In particular, incorporating the effect of urban function on surface-atmosphere exchanges into climate and NWP models is almost completely missing. Therefore, the overarching goal is to improve basic understanding of multi-scalar transport and inform physically realistic, generalizable estimates of the surface-atmosphere exchanges, especially for less explored scalars. The project will lead to findings necessary for the next-generation urban climate modeling tools, which can be implemented to develop more precise (i.e. city or neighborhood-specific) mitigation and adaptation measures with changing climates. (NSF-CAREER, 2022-2027)