Intermediate General Circulation Model
The Reading Intermediate General Circulation Model (IGCM), is a simplified or "intermediate" Global climate model, which is developed by members of the Department of Meteorology at the University of Reading, and by members of the Stratospheric Dynamics and Chemistry Group of the Department of Atmospheric and Oceanic Sciences at McGill University
The IGCM is a fast GCM based on the primitive-equations baroclinic model of Hoskins and Simmons, which has been converted to run on workstations. Several versions have been developed with representations of the physics.
- IGCM1: Portable version of the original spectral dry baroclinic model formulated in sigma-levels, with an option for Newtonian relaxation and Rayleigh friction, no surface.
- IGCM2: Includes simplified moist parameterisations, a cheap "radiation scheme" (i.e. constant tropospheric cooling), a bulk formulation scheme for the boundary layer, fixed surface temperatures and humidity, a uniform vertical diffusion, and can advect tracers.
- IGCM3x: Intermediate climate model which includes more sophisticated moist / clouds parameterisations, a radiation scheme with various gas absorbers, and a more realistic surface with an orography and land, sea surface schemes.
The adiabatic version, IGCM1, is freely available. Access to IGCM2 and IGCM3 is restricted to members of the Department of Meteorology at the University of Reading and collaborating researchers.