The effect of synoptic-scale wave breaking on cross tropopause transport and trace gas distribution

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The tropopause and the so-called tropopause inversion layer (TIL), which is a layer of high static stability act as a partly permeable barrier to trace gas exchange between the troposphere and the stratosphere. The tropopause region is of particular importance for climate. The processes which lead to the formation of the TIL and their role for stratosphere-troposphere-exchange (STE) and the chemical composition of the tropopause region are incompletely understood. Experiments with idealized models show that synoptic scale wave breaking in baroclinic life cycles leads to TIL formation. The dynamical conditions during such an event are favorable for STE and an irreversible constituent exchange across the tropopause. This project will constitute a novel approach to identify the effect of synoptic-scale wave breaking and TIL formation on STE combining idealized models and observations with statistical methods. For this purpose we will apply: (i) the same analysis methods for idealized models containing artificial tracers and trace gas observations (ii) aquaplanet simulations with a full chemical scheme and the physics of a global model, to identify the global effect of baroclinic life cycles on TIL formation and the related trace gas distribution.