Simulating turbulence and atmospheric convection over complex terrain at large-eddy scales

Stephen Nesbitt, University of Illinois at Urbana-Champaign

Usage Details

Summertime convective storms initiating near the Sierras de Córdoba (SDC) mountain range in Argentina are some of the most intense thunderstorms on the planet. These storms mostly occur over and to the east of the SDC range and are intimately tied to the regional topography, which affects their entire lifecycle, from initiation to maturation and decay. We hypothesize that convergence owing to airflow impinging on the terrain and daytime upslope flows over the mountains are the major contributors to warm-season convection initiation in the region. As part of this project, high-resolution simulations (horizontal grid spacing O(100m)) are conducted to understand the physical processes that lead to the formation of updrafts that ultimately lead to deep moist convection in the region. These simulations will then be validated using in situ observations collected in the region. The project has the potential to make significant advances in the understanding of physics of thunderstorm initiation and in improving its timely forecast not only in Argentina but worldwide. This project forms a part of the larger RELAMPAGO (Remote sensing of Electrification, Lightning and Mesoscale/microscale Processes with Adaptive Ground Observations) and CACTI (Clouds, Aerosols and Complex Terrain Interactions) projects. RELAMPAGO-CACTI projects aim to understand the initiation, maturation, and decay of these storms by taking hydrometeorological measurements in Argentina during Nov-Dec 2018. The projects together form the largest land-based atmospheric sciences field campaign ever conducted outside the U.S. and require significant computational resources, such as those provided by Blue Waters, in order to be successful. Illinois is spearheading the RELAMPAGO project with Steve Nesbitt as its Principal Investigator.