A new approach for 3D cloud‐resolving simulations of large‐scale atmospheric circulation

Abstract
We present a computationally efficient new method for simulating the interactions of large‐scale atmospheric circulations with deep convection in a 3D cloud‐resolving model. This is accomplished by reducing the scale difference between the large‐scale and convective circulations. Our method, Diabatic Acceleration and REscaling (DARE), consists of accelerating all diabatic processes, reducing the planetary radius and increasing its rotation rate. A second useful interpretation of this rescaling, Reduced Acceleration in the VErtical (RAVE) is also presented briefly. The DARE/RAVE approach is expected to be useful for a wide range of problems involving interactions between large‐scale circulation, deep convection, and associated cloud and radiation processes, whose investigation has long been plagued by deficiencies in cumulus/cloud parameterizations. Initial results from a near‐global scale equatorial β‐plane simulation using the DARE approach are briefly presented.