Simulating Shallow Mesoscale Overturning Circulations in the Trades With Kilometer‐Scale Earth System Models

Abstract Shallow mesoscale overturning circulations (SMOCs) are ubiquitous in the trades, primarily triggered by mesoscale convective heating and influencing the organization of shallow cumuli. Accurate representation of SMOCs and their co‐variability with moisture is crucial for capturing mesoscale cloud organization in models and improving climate predictions. Coarse‐resolution global climate models cannot resolve SMOCs, but multi‐decadal scenario simulations with 10 km grid spacing motivate their use for assessing SMOC representation. At kilometer‐scale resolutions, thermals of shallow convection are partially resolved, yet convective heating still relies on parameterizations for unresolved processes. Both finer grid spacing and convection schemes influence the magnitude and vertical distribution of shallow convective heating, controlling SMOC characteristics. Using A campaign data as reference, we show that models with 2.8–10 km horizontal grid spacing reproduce trade‐wind shallow circulations and their co‐variability with moisture. The findings highlight the importance of model configuration in accurately simulating the strength of mesoscale circulations.