Parametrization of the effects of atmospheric transport on absorption and cloud activation of black carbon particles in the Arctic – a new modelling-chamber approach

• Applicant: Dr. Gholamali Hoshyaripour, since 7/2023
• Subject Area: Atmospheric Science
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 457895178

The radiative forcing estimations of black carbon aerosol (BC) are significantly affected by the difficulty of models to reproduce the temporal evolution that BC properties undergo during atmospheric ageing. This is particularly true for Arctic BC, which encounter deep chemical and physical transformation during the norward long-range transport.With the present project we thus aim to improve the understanding and parametrization of BC ageing during northward Arctic transport with a combined model and simulation-chamber approach. The three-year project will be hosted by the Institute of Meteorology and Climate Research (IMK) of the Karlsruhe Institute of Technology (KIT). In a first step, the atmospheric conditions representative of northward transport between mid and Arctic latitudes for spring, summer and winter will be identified with data from ERA5 (ECMWF Reanalysis 5th Generation) and early ICON-ART (ICOsahedral Nonhydrostatic - Aerosol and Reactive Trace gases) model runs. Those information on the latitudinal gradient of temperature, relative humidity, aerosol particle and gas phase constituents, as well as of cloud presence will be then reproduced in the AIDA (Aerosol Interactions and Dynamics in the Atmosphere) chamber during realistic long-term experiments. With these experiments I aim to quantify the impact of condensation and coagulation processes as well as cloud processing on the mixing state of BC particles and on its climate relevant properties such as light absorption and cloud activity. Additional exploratory experiments in the new AIDAdynamic (AIDAd) cloud chamber will allow investigating the role of BC in Arctic mixed phase clouds. The results of AIDA and AIDAd experiments will be used to improve the aging scheme of the global model ICON-ART. The sensitivity of ICON-ART to the improved ageing parametrization will be tested with past in-situ Arctic observation performed within the AC3 (http://www.ac3-tr.de/) and NASCENT (https://www.aces.su.se/research/projects/the-ny-alesund-aerosol-cloud-experiment-nascent-2019-2020/) project. On one side the long-term AIDA experiments will provide specific insights on BC ageing process; on the other, the close collaboration with modelling researchers will indicate the possibility to constrain ageing schemes of global model with dedicated chamber experiments. This approach might be, in the future, extended to other regions of interest, atmospheric processes or aerosol types.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Cooperation Partner: Robin Lewis Modini, Ph.D.
• Co-Investigators: Dr. Ottmar Möhler; Dr. Bernhard Vogel
• Ehemaliger Antragsteller: Marco Zanatta, Ph.D., until 7/2023