Study of cloud condensation nuclei and ice nucleating particles during the Antarctic Circumnavigation Expedition (ACE)

• Applicant: Dr.-Ing. Frank Stratmann
• Subject Area: Atmospheric Science
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 366126411

The Southern Ocean (SO) region is the most pristine aerosol environment on Earth, but almost the entire region is considered as under-sampled. As partner of the -Study of Preindustrial-like-Aerosol Climate Effects- (SPACE) project we participate in the unprecedented Antarctic Circumnavigation Expedition (ACE), giving us the unique opportunity to conduct high quality aerosol measurements in this remote region. ACE-SPACE in general aims at a detailed characterization of the pristine aerosol which is unaffected by anthropogenic pollution and therefore represents an aerosol comparable to that in a pre-industrial atmosphere. Our, i.e., TROPOS special focus in context of ACE-SPACE is on aerosol particles involved in climate relevant aerosol cloud interactions, specifically on particles able to act as cloud condensation (CCN), as well as particles able to nucleate ice (INP). During ACE we will perform 3 months of continuous INP- and CCN-related in-situ measurements together with aerosol particle filter sampling on-board the Russian ice-breaker Akademik Tryoshnikov. As within ACE-SPACE we are only funded for carrying out the measurements, and chemical characterization of the filter samples, here we apply for funding (mainly 1 PhD student, 67% for three years) for the scientific evaluation, physical analysis, and interpretation of the collected samples and data. The suggested work will yield unique data concerning INP and CCN number concentrations in the SO region, as well as information with respect to the INPs ice nucleation and CCNs and activation behaviour. These data will be linked with meteorological information (e.g. back trajectories) and information on the chemical composition of the sampled aerosol particles for identifying the INPs and CCNs sources. The quantitative information on preindustrial-like CCN and INP compiled in the framework of the present proposal are made available within the SPP, but are also used by our partners within the ACE-SPACE project to evaluate and constrain global models and satellite retrieval methods.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas - with renewal proposal 2025 - 2030
• International Connection: Switzerland
• Co-Investigators: Dr. Silvia Henning; Dr. Manuela van Pinxteren; Dr. André Welti
• Cooperation Partner: Professorin Dr. Julia Schmale