The IPSL Climate Modelling Centre (IPSL-CMC) continuously develops and improves its climate model IPSL-CM and its various components. The IPSL-CM5 is the fifth version of the IPSL model and is a full earth system model. In addition to the physical atmosphere-land-ocean-sea ice model, it also includes a representation of the carbon cycle, the stratospheric chemistry and the tropospheric chemistry with aerosols.
There were initially two versions of this model, with two different sets of physical models: the IPSL-CM5A is an extension of IPSL-CM4 whereas the IPSL-CM5B has an atmospheric model with very different physical parametrisations. IPSL-CM5A has been updated to form the IPSL-CM5A2 model with the aim of having a fast version for long simulations.
For the different versions of the IPSL-CM5 models that participate to the CMIP5 project, the atmospheric model has two standard resolutions: the low resolution is 1.9°x3.75° (96x96xL39) and the mid-resolution is 1.25°x2.5° (144x143xL39). For all of them, the resolution of the oceanic model is the same: about 2°, with a meridional increased resolution of 0.5° near the Equator (149x182L31).