A large-scale investigation of soil moisture feedbacks on precipitation intensity in the central United States

Convective activity, including thunderstorms, significantly influences Earth’s climate and environment while posing substantial risks to society. Understanding the fundamental processes driving these events is crucial, particularly given the projected increase in their occurrence and intensity. Previous studies capture impacts on precipitation occurrence and distribution but lack focus on precipitation intensity, especially at a large scale. Soil moisture affects surface heat fluxes, altering the planetary boundary layer's stability, which influences convective activity. This study examines the relationship between soil moisture and precipitation intensity across the Central United States from 2005 to 2017 using the Thunderstorm Observation by Radar (ThOR) algorithm. The analysis includes over 500,000 thunderstorm data points, correlating soil moisture with storm reflectivity and vertically integrated liquid. Findings indicate a broad negative correlation between soil moisture and precipitation intensity, suggesting that drier soils lead to stronger convective storms. Pathway variables like boundary layer height and evaporative fraction drive the mechanisms by which soil moisture influences storm intensity. The results underscore the importance of soil moisture in modulating convective storm behavior, with implications for improving forecasting and understanding of land-atmosphere interactions. Further research is needed to refine these findings and explore regional variations and other influencing factors.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Atmospheric Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Lazarow, R. Mitchell

Contributors dc:contributor

• Ford, Trent

• Soil Moisture
• Thunderstorms
• Convection
• Land-atmosphere Interactions
• Surface Flux

Statement dc:rights

• Copyright 2024 R. Mitchell Lazarow

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/125636

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F125636