Numerical models are used to simulate chemical and physical processes in the atmosphere on computers. These models describe the latest state of knowledge on these processes in a mathematical form. From the mathematical formulation, numerical models are developed that allow researchers to simulate processes in the atmosphere and to make forecasts. The simulation results are subsequently compared with comprehensive high-quality atmospheric data.
High demands are made on the models. They must be able to describe measurement results of spatially small-scale transport and mixing processes in the atmosphere. Transport barriers, in particular the tropopause and stratospheric jet streams must be represented correctly, for example in order to precisely capture climate-relevant trends in the water vapour distribution. In order to simulate stratospheric ozone chemistry, models are required to describe both the fast photochemistry of ozone depletion as well as processes that occur on longer time scales. The results of such a model intensively tested with the aid of measured values can be used to verify the results of global climate models and to improve the models. Scientists at the institute have developed the Chemical Lagrangian Model of the Stratosphere (ClaMS), which fulfils these requirements.
CLaMS is employed to analyse high-resolution global satellite data as well as measurements from high-altitude aircraft and balloons. Work focuses on the polar stratosphere, the extratropical tropopause region, the tropical tropopause layer (TTL) and the Asian monsoon circulation. CLaMS analyses have also been used to support a number of measurement campaigns.
Contact: Dr. Rolf Müller