Document Type

Article

Publication Date

1-1-2025

Abstract

General circulation models (GCMs) lack the spatial resolution to capture the atmospheric and land-surface processes that shape regional climate. Regional climate models (RCMs) better resolve the interactions between large-scale weather patterns and local terrain. This study uses the Weather Research and Forecasting (WRF) model to perform high-resolution (12-km) dynamical downscaling for Louisiana and Mississippi over a historical (1996–2005) and a future (2090–2099) time span, forced by NCAR’s Community Earth System Model, version 1 (CESM1). Model performance was evaluated for the 1996–2005 period against atmospheric reanalysis and station observations, showing better skill for temperature than precipitation. Seasonal evaluation (winter: Dec-Feb; spring: Mar-May; summer: Jun-Aug; fall: Sep-Nov) indicates best performance in spring and fall, with r ≥ 0.93 and RMSE ≤ 0.72 °C for temperature, and r ≥ 0.88 and RMSE ≤ 56 mm for precipitation. Lower skill in simulating summer precipitation suggests caution when interpreting future projections. Future simulations (2090–2099) project notable widespread warming across all seasons. Precipitation changes are spatially variable and mostly insignificant, except for a significant Sep-Nov increase near the Gulf coast. Projected changes in extreme temperature indices suggest more frequent hot days along the Gulf coast and longer heatwaves in northern Louisiana and central–northern Mississippi. Contrasting trends of extreme precipitation frequency and intensity indices imply fewer but more intense precipitation events in northern Louisiana by the late 21st century. Insights from this work will contribute toward a comprehensive understanding of the potential impacts of climate change on the Gulf coast.

Publication Source (Journal or Book title)

Earth Systems and Environment

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