Impact of upper tropospheric jet-front systems on the mesoscale structure of the tropopause inversion layer and cross-tropopause transport [MESO-TIL]

• Applicant: Dr. Daniel Kunkel
• Subject Area: Atmospheric Science
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 316739189

This research proposal is dedicated to the HALO mission WISE, with a special focus on the formation of the tropopause inversion layer (TIL) and its impact on stratosphere troposphere exchange (STE) on the mesoscale. The basis for this project are recent results from idealized studies of the TIL in baroclinic life cycle experiments. Major goals are to verify predictions of the TIL formation in these idealized studies as well as to improve the understanding of processes that contribute to STE on the mesoscale. Specifically, three scientific question will be addressed in this project: (1) How variable is the TIL over the North Atlantic, especially in regions strongly influenced by baroclinic lifecycles and in regions of STE? (2) Which processes contribute most to the mesoscale variability of the TIL? (3) How large is the impact of small scale waves from the jet-front system in the lower stratosphere on the TIL and on the depth of the mixing layer? A combination of methods will be used to answer these questions. Analysis data from the ECMWF along with Lagrangian methods will be applied to study the TIL and STE over the North Atlantic which is the region of interest of the WISE mission. For the time of the WISE mission high resolution model simulations will be conducted with the new numerical weather prediction model ICON. This allows to quantify how much individual processes contribute to the TIL in real case studies in regions of cyclonic and anti-cyclonic flow. Moreover, the model data will be analyzed in combination with observational data to study the impact of the TIL and of small scale waves on the depth of the extratropical mixing layer.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1294: Atmospheric and Earth System Research with the "High Altitude and Long Range Research Aircraft" (HALO)
• Cooperation Partners: Dr. Andreas Fix; Professor Dr. Peter Hoor; Daniel Reinert; Dr. Joern Ungermann; Dr. Andreas Wieser