Gensini, Vittorio A.
M.S. (Master of Science)
Department of Geographic and Atmospheric Sciences
The impacts of anthropogenic climate change will be felt most strongly through changes in hazards such as extreme precipitation. The potential for extreme precipitation changes—both increases and decreases—may have significant societal impacts (e.g., agriculture production, loss of life and property). However, limited research has quantified future projected changes in extreme precipitation due to computational limitations and considerable time expenditure for convection-permitting simulations of substantial duration.This project sought to analyze changes in extreme daily precipitation—defined as the 99th percentile daily accumulated value—due to climate change in the contiguous United States (CONUS) using a dynamically downscaled and convection-permitting regional climate modeling framework. Simulation output includes a historical baseline (HIST; 1990–2005) and two end of twenty-first century epochs (END; 2085–2100) under intermediate mitigation (END4.5) and pessimistic (END8.5) representative concentration pathway (RCP) scenarios. The historical baseline is compared to the Parameter-elevation Regressions in Independent Slopes Model to assess the simulation performance; HIST admirably represented the extreme precipitation climatology for most locations. Comparisons between HIST and the two END scenarios evaluate spatiotemporal changes in extremes. Finally, an extreme value analysis (EVA) extracts the extremes of eight climatologically unique cities and permits the identification of changes in return period precipitation values and the distribution of extremes for each epoch. Results show the 99th percentile of daily precipitation has statistically significant increases during Dec–May in the Midwest and Ohio Valley and statistically significant decreases for the southern Great Plains in the END scenarios compared to HIST. The EVA revealed increased variability in precipitation extremes for eight climatologically unique cities across the CONUS by the end of the twenty-first century. The END scenarios displayed increases in return period precipitation values and even exceeded the 95% confidence interval of the HIST epoch for most cities examined. Overall, these results can serve as additional knowledge for stakeholders in creating a climate-resilient society to reduce deaths, injuries, and economic loss from precipitation extremes.
Stinnett, Sylvia, "Historical and Potential Future Climate of Extreme Daily Precipitation over the Contiguous United States Using Convection-Permitting Simulations" (2023). Graduate Research Theses & Dissertations. 7356.
Northern Illinois University
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