Regional climate modelling

A new technique for climate simulations and projections has emerged over the past 15 years that allows to reach unprecedented spatial resolution at an affordable computing cost: regional climate modelling. The technique has matured and several groups around the world are participating in model intercomparison projects and collaborating in coordinated endeavour to produce ensemble climate-change projections at regional scales.The paper describes the formulation of a specific regional climate model (RCM), the Canadian RCM, commenting on the formulation choices and experience gained during the development and validation process of this model. Current issues in regional climate modelling are also reviewed and discussed.