- Energy-Vorticity-Theory (EVT)
This working group’s research activities consist, among other things, in generalizations of the atmospheric base equations from the traditional Hamiltonian energy form into a new energy-vorticity theory. Practical applications in this regard lie, for instance, in the calculation of a weather and climate index (the Dynamic State Index or DSI) that is based on physical principles. To achieve this, reanalysis data from the ECMWF and the NCEP/NCAR reanalyses of the past fifty years are used to analyze the present climate. Correlations between the DSI and the North Atlantic Oscillation (NAO) index as well as the traditional meteorological variables, such as temperature and precipitation, are calculated.
In addition, a two-level spectral model is operated on the globe for conceptual issues and analysis of global processes. To ensure effective dynamics, simple point vortex models are used to describe the large-scale movement of the stratospheric polar vortex. In particular, the quasi-two-dimensional movement that is important to the dynamics of the polar vortex, with its inverse energy cascade and enstrophy cascade towards smalles scales, is examined. Another major focus for this working group is its extensive teaching activities on theoretical meteorology in the bachelor (Dynamic of Atmosphere II) and master (Theoretical Meteorology I+II) courses.