AGS-PRF: Quantifying the Dynamic and Thermodynamic Mechanisms and Response to Climate Change of Thunderstorm Precipitation in the Western United States

Kalashnikov, Dmitri Alexander, Vancouver WA

Investigators

Abstract

This postdoctoral research fellowship award is for the study of thunderstorm-related precipitation in the Western United States. The climatology of the Western US results in relatively infrequent thunderstorms, but the geography of the region means that thunderstorms that do occur can have significant impacts. Western US thunderstorms are disproportionately related to both flash flooding and wildfire ignition from lightning. This project will study the meteorological factors that drive western US thunderstorm precipitation, evaluate projected changes in these factors, and examine their impact on current and future projections of thunderstorm activity. Improved understanding of these hazards is likely to result in better forecasting and more informed risk management. The fellowship will also allow the postdoctoral researcher to gain new skills and set them on a path towards scientific leadership in the field. This award addresses several key gaps in our understanding of thunderstorm-related precipitation in the western US, its physical drivers, and changes in daily-scale thunderstorm precipitation in a warmer climate. The project will have a multi-step approach to address two overarching science questions. First, the researcher will use observational rainfall and lightning data and model reanalysis data to analyze the atmospheric moisture budget to address Research Question 1: What is the relative importance of dynamic and thermodynamic contributions to thunderstorm precipitation across the Western US, and what is the magnitude of their roles in observed changes? Secondly, the research will use large-ensemble climate models, partially analyzed with machine learning, to quantify the contribution of changes in the dynamic and thermodynamic drivers of thunderstorm precipitation to address Research Question 2: What is the role of decadal climate variability in the observed changes in thunderstorm precipitation in the Western US, and how is thunderstorm precipitation projected to change in the future? This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.