CLaMS is a Lagrangian transport model suitable for simulating atmospheric transport and chemistry. The novel approach of CLaMS is its description of atmospheric mixing. Whereas the common approach is to minimize the numerical diffusion ever present in the modeling of transport, CLaMS is a first attempt to apply this undesirable disturbing effect to parametrize the true physical mixing. In this paper, we show how this concept works both in the stratosphere and in the troposphere.