Earth and Atmospheric Sciences, Department of
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
First Advisor
Adam L. Houston
Date of this Version
12-2025
Document Type
Thesis
Citation
A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science
Major: Earth and Atmospheric Science
Under the supervision of Professor Adam L. Houston
Lincoln, Nebraska, December 2025
Abstract
The continued spread of urbanization and its well-documented effects on regional weather and climate necessitate further research. Urban environments are often warmer and drier than their rural surroundings. This trade-off between a warmer but drier environment could have a complex impact on deep convection and its initiation. Previous studies have noted significant changes in precipitation patterns around cities as well as changes to ongoing deep convection. Given the well-documented theory and past research, it is hypothesized here that urban areas have a significant impact on the PBL thermodynamics of convective environments. The urban heat island (UHI) component of the Micro - Small-UAS Coordination for Atmospheric Low-Level Environmental Sampling (MicroSCALES-UHI) field campaign collected in-situ observations in and around Tulsa, Oklahoma, 9-13 September 2024. MicroSCALES-UHI used a network of uncrewed aircraft systems (UAS) to produce an in-situ dataset with high spatiotemporal resolution within an urban environment.
The goal of this work is to use this unique dataset to characterize the 4D impacts of urbanization on convective environments. Typical UHI modifications are observed with slightly warmer temperatures and lower mixing ratios than the rural surroundings. Analysis revealed that the urban modifications created areas of decreased total potential energy and moist static energy. This suggests decreased potential for deep convection initiation (DCI). In contrast, analysis revealed higher LCLs, suggesting possible increases to initial parcel/updraft size and an increased potential for DCI. Furthermore, steeper near-surface superadiabatic lapse rates, potentially enhancing buoyancy and lift, and a delayed transition from a convective boundary layer to a nocturnal boundary layer have implications for DCI and existing convection. Local zones of decreased buoyancy around urban centers suggest that while thermal perturbations from the UHI may influence DCI, other competing processes make the overall effect on DCI ambiguous.
Advisor: Adam L. Houston
Comments
Copyright 2025, Benjamin W. Moll. Used by permission