Tests of atmospheric General Circulation Models (GCMs) and, in particular, tests of their dynamical cores are important steps towards future model improvements. They reveal the influence of an individual model design on climate and weather simulations and indicate whether the circulation is described representatively by the numerical approach.
Testing a global 3D atmospheric model is not straightforward. In the absence of non-trivial analytic solutions, the model evaluations most commonly rely on intuition, experience and model intercomparisons. In addition, GCM simulation statistics are typically compared to global reanalysis data while numerical weather forecasts are compared to local observations. Such approaches are not applicable to pure dynamical core assessments that isolate the dynamics package from the physical parameterizations. In general, three different sets of equations are most commonly used in dynamical cores. These include the hydrostatic primitive equations as well as the non-hydrostatic shallow-atmosphere and non-hydrostatic deep-atmosphere equation sets. As modeling groups now move towards the next generation of dynamical cores a standard test suite for hydrostatic and non-hydrostatic dynamics packages on the sphere if highly desirable. This webpage contributes to this effort. It suggests a collection of dynamical core test cases with varying complexity.

The following test suite for atmospheric model dynamical cores is proposed:

click on the PowerPoint presentation, PDEs on the Sphere Workshop, Monterey, CA, June/26-29/2006 (download the pdf version, 1.2MB),

Poster Presentation at the 11th Annual CCSM Workshop, Breckenridge, CO, June/20-22/2006 and the
AGU Fall Meeting 2006, San Francisco, CA, Dec/11-15/2006 (download the poster (ppt file), 2.3MB)

Jablonowski, C. (2006a): A Proposed Test Suite for Atmospheric Model Dynamical Cores. Poster presentation at the 11th Annual CCSM Workshop, Breckenridge, CO, June/20-22/2006

Jablonowski, C. (2006b): A Proposed Test Suite for Atmospheric Model Dynamical Cores, Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract A41D-0062

Jablonowski, C. and D. L. Williamson (2006): A Baroclinic Instability Test Case for Atmospheric Model Dynamical Cores, Quarterly J. Roy. Met. Soc., Vol. 132, October Part C, No. 621C, 2943-2975
Also available online at http://www.umich.edu/~cjablono/QJ_Jablonowski_Williamson_2006.pdf

Dr. David L. Williamson, National Center for Atmospheric Research (NCAR), Boulder, CO