Development of a Global Quasi-3-D Multiscale Modeling Framework

 
Poster PDF

Authors

Joon-Hee Jung — Colorado State University - Atmospheric Science Department
Celal Konor — Colorado State University
David A. Randall — Colorado State University

Category

General topics

Description

The Quasi-Three-Dimensional Multiscale Modeling Framework (Q3D MMF) is a second-generation super-parameterization. It has the following improvements relative to the first-generation MMF: 1) The cloud-resolving models (CRMs) are not artificially confined to the GCM grid cells with periodic lateral boundary conditions; instead, the CRMs take the form of “channels” that wrap around the globe, so that cloud systems can propagate freely along the channels. 2) The CRMs are formulated so that they can sense the three-dimensional gradients associated with the large-scale and cloud-scale environments. 3) Two perpendicular sets of CRM channels are used, eliminating the need to select a particular orientation for the CRMs. The basic design of the Q3D MMF has been developed and tested in a limited-area modeling framework. Currently, global versions of the Q3D MMF are being created with the Spectral Element (SE) cubed-sphere dynamical cores of both Community Atmosphere Model (CAM) and the atmosphere model of the Energy Exascale Earth System Model (E3SM). These dynamical cores govern the large-scale circulations in the global Q3D MMF. For the CRMs that replace the conventional subgrid-scale parameterizations of deep convection, the 3-D nonhydrostatic anelastic Vector-Vorticity Model (VVM) is used. The parameterizations of microphysics, turbulence and shallow convection, and radiation are implemented on the CRM’s fine grid. For easy coupling with the dynamical cores, the VVM has been adapted to the cubed-sphere grid and successfully tested. In this poster, we describe the global Q3D MMF based on the CAM-SE Dycore and present its simulated test results.