Sensitivity of tropical deep convection in global models: effects of horizontal resolution, surface constraints, and 3D atmospheric nudging

We investigate the ability of global models to capture the spatial patterns of tropical deep convection. Their sensitivity is assessed through changing horizontal resolution, surface flux constraints, and constraining background atmospheric conditions. We assess two models at typical climate and weather forecast resolutions. Comparison with observations indicates that increasing resolution generally improves the pattern of tropical convection. When the models are constrained with realistic surface fluxes and atmospheric structure, the location of convection improves dramatically and is very similar irrespective of resolution and parameterizations used in the models.