Air Mass Origin in the Lower Stratosphere using HALO Measurements and CLaMS Simulations (AMOS)

• Applicant: Dr. Bärbel Vogel
• Subject Area: Atmospheric Science
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 316738484

Direct transport pathways from the troposphere into the lower stratosphere of water vapour and and other tropospheric trace gases (e.g. other greenhouse gases or ozone-depleting substances such as very short lived species and halogens) influence the chemical composition of the extratropical upper troposphere and lower stratosphere (ExUTLS). Changes in ozone and water vapour in the ExUTLS, have a significant impact on surface climate, even if the perturbation is relatively small. Discussed are direct Transport pathways such as quasi-horizontal transport from the Tropical tropopause layer, horizontal transport from the the Asian monsoonanticyclone and convection induced injections. However, currently the understanding of these transport processes is incomplete. Within our project AMOS, we would like to identify and quantify the underlying transport processes for different previous (TACTS/ESMVal) and upcomingHALO campaigns (PGS, WISE) to identify the seasonal and the inter-annual variability of these transport processes. The focus of our project will be on the upcoming WISE campaign which is focused on transport processes that determine the chemical composition of the ExUTLS. In our project, we will use HALO measurements and perform several simulations with the Lagrangian model (CLaMS) using artificial tracers of air mass origin. CLaMS using artificial tracers of air mass origin is an unique tool to describe accurately the essential transport and mixing processes and can help to quantify the impact of These different transport pathways on the chemical composition of the lower stratosphere.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1294: Atmospheric and Earth System Research with the "High Altitude and Long Range Research Aircraft" (HALO)
• Co-Investigator: Dr. Gebhard Günther