HAPpy Hour Seminar: Convection-Permitting Dynamical Downscaling of Current and Future Climate over South America

Abstract: Over the past few years, the NCAR Water System Program has led a continental-scale, convection-permitting regional climate modeling initiative centered on South America. This effort involves multiple phases of WRF model simulations at 4-km grid spacing, encompassing the entire South American continent and adjacent oceanic regions. 

The project has two primary objectives: (1) to develop a high-resolution community dataset to support detailed studies of hydroclimate processes and climate change impacts; and (2) to examine the spatiotemporal characteristics and multiscale dynamics of the continental water cycle, along with their potential responses to future climate warming.

The first part of my talk will provide an overview of two multi-decade simulations: a retrospective simulation that reproduces climate conditions from 2000 to 2021, and a climate sensitivity simulation that explores the hydroclimate response to future warming, based on the CMIP6 SSP3-7.0 scenario and using the Pseudo Global Warming (PGW) approach. This will be followed by a discussion of the potential benefits of scale-aware convective parameterization and spectral nudging, as well as an analysis of the added value of convection-permitting resolution compared to coarser-resolution simulations. I will conclude by highlighting current model limitations and outlining potential directions for future improvements.