Sea salt aerosol in snow on sea ice as a potential source of Ice Nucleating Particles in the Arctic

• Main Authors: Kirchgaessner, A., Frey, M., van den Heuvel, F., Yang, X., Lachlan-Cope, T.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Arctic; Sea ice
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018930

Our lack of understanding with respect to the sources and nucleating capabilities of natural aerosol in the high Arctic is one reason why Arctic clouds are still poorly represented in climate models. Recent field campaigns provide evidence of a source of sea salt aerosol (SSA) from blowing snow above sea ice, which can account for the SSA winter/spring maxima observed in the Polar Regions. This SSA has the potential to influence the regional climate through the indirect radiative effect, but the relative magnitude of its contribution to cloud forming particles, especially ice nucleating particles (INP), are still largely unknown. For this presentation we use online and offline measurements of airborne aerosol for its ice nucleating properties that were carried out in the Central Arctic during MOSAiC. We combine these with INP measurements from snow samples, observations of snow particle fluxes, and aerosol measurements from the comprehensive MOSAiC data set. Online observations of INP in spring show concentrations in the order of a few tens [particle m-3], that were often associated with high wind speeds. Initial offline analyses of snow samples from the sea ice taken during the same period indicate the presence of INPs. This is evidence that snow on sea ice represents a viable source of INPs, which may release these particles via blowing snow into the atmosphere.