Evidence for marine biogenic influence on summertime Arctic aerosol

• Published in: Geophysical Research Letters
• Main Authors: Willis, Megan D., Köllner, Franziska, Burkart, Julia, Bozem, Johannes, Thomas, Jennie L., Schneider, Johannes, Aliabadi, Amir A., Hoor, Peter M., Schulz, Hannes, Herber, Andreas B., Leaitch, W. Richard, Abbatt, Jonathan P. D.
• Other Authors: Department of Chemistry University of Toronto, University of Toronto, Max-Planck-Institut für Chemie (MPIC), Max-Planck-Gesellschaft, Institut für Physik der Atmosphäre Mainz (IPA), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), School of Engineering Guelph, University of Guelph, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Environment and Climate Change Canada
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: secondary organic aerosol; Arctic summer; aerosol mass spectrometry; Arctic aerosol; marine organic aerosol; methanesulfonic acid; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic
• Online Access: https://insu.hal.science/insu-01539519; https://insu.hal.science/insu-01539519/document; https://insu.hal.science/insu-01539519/file/2017GL073359.pdf; https://doi.org/10.1002/2017gl073359

International audience We present vertically-resolved observations of aerosol composition during pristine summertime Arctic background conditions. The methansulfonic acid (MSA)-to-sulfate ratio peaked near the surface (mean 0.10), indicating a contribution from ocean-derived biogenic sulfur. Similarly, the organic aerosol (OA)-to-sulfate ratio increased towards the surface (mean 2.0). Both MSA-to-sulfate and OA-to-sulfate ratios were significantly correlated with FLEXPART-WRF-predicted airmass residence time over open water, indicating marine influenced OA. External mixing of sea salt aerosol from a larger number fraction of organic, sulfate and amine-containing particles, together with low wind speeds (median 4.7 m s −1 ), suggests a role for secondary organic aerosol formation. Cloud condensation nuclei concentrations were nearly constant (∼120 cm −3 ) when the OA fraction was <60% and increased to 350 cm −3 when the organic fraction was larger and residence times over open water were longer. Our observations illustrate the importance of marine-influenced OA under Arctic background conditions, which are likely to change as the Arctic transitions to larger areas of open water.