OCEAN to atmosphere transfer and biogenic in-situ formation of atmospheric relevant orGanic matter in AnTarctic aErosol particles (OCEAN-GATE)

• Applicant: Dr. Manuela van Pinxteren
• Subject Area: Atmospheric Science
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 470040273

Aerosol particles are important and to date not well-understood components that drive the formation of clouds and strongly influence Earth’s radiative budget. Their origins and chemical composition, especially the organic part, are to date largely unexplored. Despite the knowledge on marine organic matter (OM) groups, the nature of OM in the ocean and in aerosol particles is still poorly resolved on a molecular level , however required to elucidate sources, transfer and formation mechanisms. Within OCEAN-GATE we aim to fill the big gaps of knowledge that exist concerning the sources, transfer and in-situ formation/degradation of atmospheric relevant OM by applying elaborated field measurements and tank (bubble-bursting generated sea spray aerosol) experiments. We will participate in the field campaign POLARCHANGE covering the costal ocean west of the Antarctic Peninsula from 60°S,50°W to 69°S, 70°W, that is, due to its pristine atmosphere, an ideal area for studying ocean-atmospheric interaction. We will analyse a broad spectrum of OM on a molecular level (e.g. carbohydrates, proteins) in various ambient and tank-generated matrices including seawater, the sea surface microlayer (SML), sea ice and size-resolved aerosol particles.Within OCEAN-GATE, our ultimate objectives are to understand the selective enrichment of organic components that occurs during the production of sea-spray aerosol particles, together with potential atmospheric in-situ OM formation and transformation. The organic parameters will be combined with further aerosol parameters (ice-nucleating particle (INP) concentrations, aerosol size distributions) and biological information (chlorophyll-a, phytoplankton groups) to elucidate the connection of biological formation of OM compounds in the ocean and in the atmosphere. Finally, our measurements will support a currently developed parameterization that considers marine organic aerosol species groups. Hence, the expected results from OCEAN-GATE will be extremely valuable for a better modeling of OM transfer from the ocean to the atmosphere.

• DFG Programme: Research Grants
• Co-Investigators: Dr. Dominik van Pinxteren; Dr. Heike Wex