Ice nucleating particles in the marine boundary layer in the Canadian Arctic during summer 2014

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Irish, Victoria, Hanna, Sarah, Willis, Megan, China, Swarup, Thomas, Jennie, Wentzell, Jeremy, Cirisan, Ana, Si, Meng, Leaitch, W. Richard, Murphy, Jennifer, Abbatt, Jonathan, Laskin, Alexander, Girard, Eric, Bertram, Allan
• Other Authors: Department of Chemistry Vancouver (UBC Chemistry), University of British Columbia (UBC), Department of Chemistry University of Toronto, University of Toronto, William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Institut des Géosciences de l’Environnement (IGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Air Quality Research Division Toronto, Environment and Climate Change Canada, Département des sciences de la terre et de l'atmosphère Montréal (SCTA), Université du Québec à Montréal = University of Québec in Montréal (UQAM), Climate Research Division Toronto, Department of Chemistry West Lafayette, Purdue University West Lafayette
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic; Baffin Bay; Canada; Greenland; Hudson; Hudson Bay; Baffin
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01993687; https://hal-insu.archives-ouvertes.fr/insu-01993687/document; https://hal-insu.archives-ouvertes.fr/insu-01993687/file/acp-19-1027-2019.pdf; https://doi.org/10.5194/acp-19-1027-2019

International audience Ice nucleating particles (INPs) in the Arctic can influence climate and precipitation in the region; yet our understanding of the concentrations and sources of INPs in this region remain uncertain. In the following, we (1) measured concentrations of INPs in the immersion mode in the Cana-dian Arctic marine boundary layer during summer 2014 on board the CCGS Amundsen, (2) determined ratios of surface areas of mineral dust aerosol to sea spray aerosol, and (3) investigated the source region of the INPs using particle dispersion modelling. Average concentrations of INPs at − 15, −20, and −25 • C were 0.005, 0.044, and 0.154 L −1 , respectively. These concentrations fall within the range of INP concentrations measured in other marine environments. For the samples investigated the ratio of mineral dust surface area to sea spray surface area ranged from 0.03 to 0.09. Based on these ratios and the ice active surface site densities of mineral dust and sea spray aerosol determined in previous laboratory studies, our results suggest that mineral dust is a more important contributor to the INP population than sea spray aerosol for the samples analysed. Based on particle dispersion modelling , the highest concentrations of INPs were often associated with lower-latitude source regions such as the Hudson Bay area, eastern Greenland, or northwestern continental Canada. On the other hand, the lowest concentrations were often associated with regions further north of the sampling sites and over Baffin Bay. A weak correlation was observed between INP concentrations and the time the air mass spent over bare land, and a weak negative correlation was observed between INP concentrations and the time the air mass spent over ice and open water. These combined results suggest that mineral dust from local sources is an important contributor to the INP population in the Canadian Arctic marine boundary layer during summer 2014.