Preliminary Results from a Dry Global Variable-Resolution Primitive Equations Model

ABSTRACT The viability of a proposed global variable-grid strategy was previously tested (Cote et al., 1993) using a shallow-water-equations prototype. It was demonstrated that by using a global variable-resolution mesh, a high-resolution short-term forecast can be obtained for a region of interest at a fraction of the cost of using uniformly-high resolution everywhere. The prototype is generalized here to use the hydrostatic primitive equations. Preliminary results obtained with an adiabatic version of this baroclinic model are presented. They confirm the potential of the proposed strategy: differences between the 48-h forecasts for the 500 hPa geopotential height and mean-sea-level pressure fields obtained from a uniform 1.2° model, and those obtained from a variable-mesh model with equivalent resolution on a 81.6° × 60° sub-domain, are small.