Climate and climate change in western Canada as simulated by the Canadian regional climate model

A first climate simulation performed with the novel Canadian Regional Climate Model (CRCM) is presented The CRCM is based on fully elastic non-hydrostatic field equations, which are solved with an efficient semi-implicit semi-Lagrangian (SISL) marching algorithm, and on the parametrization package of subgrid-scale physical effects of the second-generation Canadian Global Climate Model (GCMII). Two 5-year integrations of the CRCM nested with GCMII simulated data as lateral boundary conditions are made for conditions corresponding to current and doubled CO2 scenarios. For these simulations the CRCM used a grid size of 45 inn on a polar-stereographic projection, 20 scaled-height levels and a time step of 15 min; the nesting GCMII has a spectral truncation of T32, IO hybrid-pressure levels and a time step of 20 min. These simulations serve to document: (1) the suitability of the SISL numerical scheme for regional climate modelling, (2) the use of GCMII physics at much higher resolution than in the nesting model, (3) the ability of the CRCM to add realistic regional-scale climate information to global model simulations, and (4) the climate of the CRCM compared to that of GCMII under two greenhouse gases (GHG) scenarios.