History of Regional Climate Modeling

Pioneering Work

The first wide use of a mesoscale meteorological model for climate simulations was initiated at the National Center for Atmospheric Research by Robert Dickinson, Ron Errico, Filippo Giorgi,and Gary Bates (Dickinson et al, 1989). The NCAR-Penn State Mesoscale Model (Anthes and Warner, 1978) version MM4 was the basic code used in this development, but several of the routines had to be modified for the code to run in climate mode. Most notably, the radiative transfer scheme and surface physics and soil hydrology processes were modified for long-term runs. Additionally, modifications to the convective precipitation and surface air temperature calculations were made.

Documentation of the current version of the model, which has become known as RegCM2, is given by Giorgi et al. (1993a, 1993b). Because it is a publicly available model, RegCM2 has become widely used across the US and in many other countries for a variety of climate variability and climate change studies. Its modular design makes it relatively easy to modify by introducing alternative subroutines for representing convective precipitation and surface-layer and subsurface processes. As a result, numerous researchers have adapted the basic code for their own use by replacing one or more of the physical parameterization schemes.

Many other mesoscale meteorological models have been converted to run in climate mode. In 1994 a project, known and the Project to Intercompare Regional Climate Simulations (PIRCS) was begun to intercompare various features of these models. The PIRCS mission is to provide a common framework for evaluating strengths and weaknesses of regional climate models and their component procedures through systematic, comparative simulations

Currently about 18 models are affiliated with PIRCS.


Anthes, R. A., and T. T. Warner, 1978: Development of hydrodynamical models suitable for air pollution and other mesometeorological studies. Mon. Wea. Rev., 106, 1045-1078.

Dickinson, R. E., R. M. Errico, F. Giorgi, and G. T. Bates, 1989: A regional climate model for the western US. Climatic Change, 15, 383-422.

Giorgi, F., M. R. Marinucci, G. T. Bates, and G. De Canio, 1993a: Development of a second-generation regional climate model (RegCM2). Part I: Boundary-layer and radiative transfer processes, Mon. Wea. Rev., 121, 2794-2813.

Giorgi, F., M. R. Marinucci, and G. T. Bates, 1993b: Development of a second-generation regional climate model (RegCM2). Part II: Convective processes and assimilation of lateral boundary conditions. Mon. Wea. Rev., 121, 2814-2832.


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