A Quasi-Equilibrium Tropical Circulation Model—Implementation and Simulation*

The quasi-equilibrium tropical circulation model (QTCM1) is implemented and tested. The formulation, described by Neelin and Zeng, uses a Galerkin framework in the vertical, but with basis functions tailored to quasi-equilibrium deep convective physics via analytical solutions. QTCM1 retains a single vertical structure of temperature and humidity. For a balanced treatment of dynamics and subgrid-scale physics, a physics parameterization package of intermediate complexity is developed. This includes a linearized longwave radiation scheme, a simple cloud prediction method, simple shortwave radiation schemes, and an intermediate land surface model.