Graduation Semester and Year
Spring 2025
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Earth and Environmental Science
Department
Earth and Environmental Sciences
First Advisor
Arne Winguth
Abstract
ABSTRACT
IMPACT OF CLIMATE CHANGE ON
NORTH CENTRAL TEXAS
Diana Kay Thomas Hansen, Ph.D.
The University of Texas at Arlington, 2025
Supervising Professor: Arne M.E. Winguth
The North Central Texas region is a rapidly expanding metropolitan area. One of the largest climate hazards that will affect human health in this region are extended heat waves and heavy precipitation. This study will examine how these hazards will change in response to climate change and the impact to human health due to weather extremes in a changing climate.
Coupled Model Intercomparison Project (Phase 6) simulations were used to evaluate future projected temperature and precipitation. Temperature change will create more heat waves in the study area. To determine the extent of this impact, climate model output was used to determine the number of excessive heat (≥37.8°C) days each year for the decades of 2041-2050 and 2091-2100 relative to 1991-2000. The excessive heat season as defined by onset and termination of excessive heat days increases in both length and intensity during the century. Additional factors influencing the initiation of heat waves are soil moisture, precipitation and evaporation, and sensible and latent heat flux.
Precipitation increases throughout the 21st century. Three threshold methods were employed to determine extreme precipitation events including the averaging of the 1/3 highest precipitation events, the number of days with precipitation ≥ 7 mm/day events particularly during Spring, and precipitation intensity anomalies. The latter were negative during all seasons except Spring at mid-century. During the last decade of the 21st century summer is the only season with positive intensity anomalies. There is evidence that compound events, high temperature followed by a precipitation event, are occurring in all time periods, with the most events occurring during 2041-2050. The temperature during the last decade may be too excessive thus resulting in high evapotranspiration and thus low precipitation.
In North Central Texas excessive heat (≥37.8 °C) will have the largest impact on human health. Heating / Cooling Degree Days will decrease / increase, creating an overall increase in the energy required to keep structures comfortable (65 °F). The Heat Index, as determined by the National Weather Service, will increase throughout the century creating dangerous levels of heat, especially for the portion of the population that works outside or those persons with chronic health conditions. North Central Texas has seen an increase in vector-borne diseases such as West Nile Virus carried by mosquitos. The number of days of mosquito activity will change in the future due to changes in temperature and humidity. Based on temperature, precipitation (including SPI), evaporation, soil moisture, sensible and latent heat flux, moderate drought is projected during the last part of the century. However, short-term drought prediction remains challenging.
Keywords
Heat waves, Extreme precipitation, Energy demand, Active mosquito days, Heat index, Drought, North Central Texas
Disciplines
Other Earth Sciences
License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
Hansen, Diana K. T., "Impact of Climate Change on North Central Texas" (2025). Earth & Environmental Sciences Dissertations. 94.
https://mavmatrix.uta.edu/ees_dissertations/94