Frequent new particle formation over the high Arctic pack ice by enhanced iodine emissions

• Published in: Nature Communications
• Main Authors: Baccarini, Andrea, Karlsson, L., Dommen, J., Duplessis, P., Vüllers, J., Brooks, I.M., Saiz-Lopez, A., Salter, M., Tjernström, M., Baltensperger, U., Zieger, P., Schmale, Julia
• Other Authors: Swedish Polar Research Secretariat, National Science Foundation (US), Swiss National Science Foundation, Swiss Polar Institute, Knut and Alice Wallenberg Foundation, Swedish Research Council, Natural Environment Research Council (UK), Ferring Pharmaceuticals, European Commission, University of Helsinki, Environment and Climate Change Canada, National Centre for Atmospheric Science (UK), Stockholm University
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Publishing Group 2020
• Subjects: Arctic; Arctic Ocean; Swedish Polar Research Secretariat; Swiss Polar Institute
• Online Access: http://hdl.handle.net/10261/228949; https://doi.org/10.1038/s41467-020-18551-0; https://doi.org/10.13039/501100004914; https://doi.org/10.13039/501100004063; https://doi.org/10.13039/501100000662; https://doi.org/10.13039/100000001; https://doi.org/10.13039/501100000270; https://doi.org/10.13039/501100009244; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100008638

11 pags., 4 figs.-- Correction: https://www.nature.com/articles/s41467-020-19533-y In the central Arctic Ocean the formation of clouds and their properties are sensitive to the availability of cloud condensation nuclei (CCN). The vapors responsible for new particle formation (NPF), potentially leading to CCN, have remained unidentified since the first aerosol measurements in 1991. Here, we report that all the observed NPF events from the Arctic Ocean 2018 expedition are driven by iodic acid with little contribution from sulfuric acid. Iodic acid largely explains the growth of ultrafine particles (UFP) in most events. The iodic acid concentration increases significantly from summer towards autumn, possibly linked to the ocean freeze-up and a seasonal rise in ozone. This leads to a one order of magnitude higher UFP concentration in autumn. Measurements of cloud residuals suggest that particles smaller than 30 nm in diameter can activate as CCN. Therefore, iodine NPF has the potential to influence cloud properties over the Arctic Ocean. The Swedish Polar Research Secretariat (SPRS) provided access to the I/B Oden and logistical support in collaboration with the U.S. National Science Foundation. This work was supported by the Swiss National Science Foundation (grant no. 200021_169090), the Swiss Polar Institute, the BNP Paribas Swiss Foundation (Polar Access Fund 2018), the Knut-and Alice-Wallenberg Foundation within the ACAS project (Arctic Climate Across Scales, project no. 2016.0024), the Bolin Centre for Climate Research (RA2), the Swedish Research Council (project nos. 2018-05045 and 2016-05100) and by the Natural Environment Research Council (grant no. NE/R009686/1). J.S. holds the Ingvar Kamprad Chair, sponsored by Ferring Pharmaceuticals. A.S.-L. acknowledges the funding from the European Research Council Executive Agency under the European Union’s Horizon 2020 Research and Innovation program (Project ‘ERC-2016-COG 726349 CLIMAHAL’). Funding of the expedition AO2018 was provided to Caroline Leck by the ...