Convection Characteristics and Thermodynamics in the Regionally Refined Simple Convection Resolving E3SM Atmosphere Model (RRM-SCREAM) over Mountainous Areas During the CACTI Campaign

This work presents a detailed evaluation of convection characteristics and associated thermodynamics in the Regionally Refined Simple Convection Resolving E3SM Atmosphere Model (RRM-SCREAM), focusing on the CACTI (Cloud, Aerosol, and Complex Terrain Interactions) field campaign. We investigate the dynamics of intense, narrow precipitation clusters, known as "popcorn convection", and their thermodynamic impacts in RRM-SCREAM. Through comparative analysis with large-eddy simulations, reanalysis data, and field observations, we evaluate the model's performance in capturing these convection characteristics. This study tracks the evolution of precipitation clusters in RRM-SCREAM to analyze their size, intensity, and impact on thermodynamic conditions while comparing the frequency, duration, and movement of these clusters to satellite observations and reanalysis data. These convective events are marked by rapid, localized cooling, which enhances atmospheric stability, disrupts vertical mixing, and leads to a decoupling between the convective system and surface processes. Since the popcorn convection problem is one of the hallmark issues with global storm-resolving models, this study particularly emphasizes potential biases that introduce changes to the lifecycle of convective clusters over land in the representation of feedback mechanisms controlling the growth and decay of convection. This work contributes to the refinement of convection-resolving models and enables further knowledge of convection dynamics by integrating high-resolution simulations with observational data.