CLaMS

CLaMS (Chemical Lagrangian Model of the Stratosphere) is a modular chemistry transport model (CTM) system developed at Forschungszentrum Jülich, Germany. CLaMS was first described by McKenna et al. (2000a,b) and was expanded into three dimensions by Konopka et al. (2004). CLaMS has been employed in recent European field campaigns THESEO, EUPLEX, TROCCINOX SCOUT-O3, and RECONCILE with a focus on simulating ozone depletion and water vapour transport. Major strengths of CLaMS in comparison to other CTMs are its applicability for reverse domain filling studies its anisotropic mixing scheme its integrability with arbitrary observational data its comprehensive chemistry scheme CLaMS gridding Unlike other CTMs (e.g. SLIMCAT, REPROBUS), CLaMS operates on a Lagrangian model grid (see section about model grids in general circulation model): an air parcel is described by three space coordinates and a time coordinate. The time evolution path that an air parcels traces in space is called a trajectory. A specialised mixing scheme ensures that physically realistic diffusion is imposed on an ensemble of trajectories in regions of high wind shear.