The Canadian Meteorological Centre's Atmospheric Transport and Dispersion Modelling Suite

AbstractThis paper describes the integrated suite of Lagrangian transport and dispersion models in operation at the Canadian Meteorological Centre. These models have been in use for several years and are applied to many types of environmental emergencies covering spatial scales from the very local to the global. The Modele Lagrangien Courte Distance (MLCD) is used for atmospheric spills of the order of a few kilometres. The Modele Lagrangien de dispersion de particules d'ordre 1 (MLDP1) is normally used for events affecting areas less than 100 km; Modele Lagrangien dispersion de particules d'ordre zero (MLDP0) is used for events of continental and global consequences. The Modele Lagrangien dispersion de particules mode mixte (MLDPmm) alternates between first-order and zeroth-order depending on criteria specified by the user. The theoretical bases of the models are presented, and the main algorithms used in their implementation are discussed. Modelling of the diffusion processes is based on a stochastic di...