Regional climate model

From Glossary of Meteorology

regional climate model

A regional climate model (Abbreviated RCM) is a numerical climate prediction model forced by specified lateral and ocean conditions from a general circulation model (GCM) or observation-based dataset (reanalysis) that simulates atmospheric and land surface processes, while accounting for high-resolution topographical data, land-sea contrasts, surface characteristics, and other components of the Earth-system. Since RCMs only cover a limited domain, the values at their boundaries must be specified explicitly, referred to as boundary conditions, by the results from a coarser GCM or reanalysis; RCMs are initialized with the initial conditions and driven along its lateral-atmospheric-boundaries and lower-surface boundaries with time-variable conditions. RCMs thus downscale global reanalysis or GCM runs to simulate climate variability with regional refinements. It should be noted that solutions from the RCM may be inconsistent with those from the global model, which could be problematic in some applications.

new term added 9July2013