Global Circulation and Climate

Group Leader: Hauke Schmidt

Our aim is to better understand how atmospheric diabatic processes and circulation interact on the global scale and how this shapes Earth’s climate.

One focus of our group is to better understand the role of the tropical tropopause layer (TTL) in a changing climate. It is clear that this region is influenced by a variety of factors like tropospheric and stratospheric composition and temperature, tropical convection and clouds, and the upwelling of the Brewer-Dobson circulation, but little is known on how these processes interact in the TTL’s response to a changing climate and which feedbacks it may provide on climate, e.g. through changes in upper tropospheric stability or the entry rate of water vapour into the stratosphere.

Other topics of interest for us are, e.g., interactions between heating and circulation, large-scale circulation patterns in a changing climate, the role of interactions with the ocean and land surfaces for atmospheric circulation, and extreme climates.

A strategy to reach our scientific goals is to make use of a hierarchy of global climate models from 1D-radiative convective equilibrium to the ICON-Earth system model. Increasing computational capacities allow to resolve (and not parameterize) processes like convection or gravity waves in 3D atmospheric or even coupled atmosphere-ocean models, at least for simulations of a few months to years, and thereby study their interactions with circulation patterns. A challenge we want to tackle lies in transferring knowledge on such interactions gained e.g. with convection-resolving models to climate time scales. Or, expressed in terms of our MPI-M’s modeling strategy, we try to link the knowledge gained in the convection-resolving experiments done in the SAPPHIRE project to the longer time-scales only accessible to RUBY-type modelling.

 

The "Global Circulation and Climate" group exists since August 2018. Some of its members were in the "Middle and Upper Atmosphere" and "Climate Dynamics" groups before. For past scientific activities see the legacy websites of those groups.