Boundary layer and free-tropospheric dimethyl sulfide in the Arctic spring and summer

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Ghahremaninezhad, Roghayeh, Norman, Ann-Lise, Croft, Betty, Martin, Randall V., Pierce, Jeffrey R., Burkart, Julia, Rempillo, Ofelia, Bozem, Heiko, Kunkel, Daniel, Thomas, Jennie L., Aliabadi, Amir A., Wentworth, Gregory R., Levasseur, Maurice, Staebler, Ralf M., Sharma, Sangeeta, Leaitch, Richard
• Other Authors: Department of Physics and Astronomy Calgary, University of Calgary, Department of Physics and Atmospheric Science Halifax, Dalhousie University Halifax, Department of Atmospheric Science Fort Collins, Colorado State University Fort Collins (CSU), Department of Chemistry University of Toronto, University of Toronto, Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Environmental Engineering Program Guelph, University of Guelph, Department of Biology Québec, Université Laval Québec (ULaval), Environment and Climate Change Canada (ECCC), Natural Sciences and Engineering Research Council of Canada (NSERC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]; Arctic Archipelago; Arctic; Arctic Ocean; Baffin Bay; Baffin; Canadian Archipelago; Canadian Arctic Archipelago; Eureka; Greenland; Inuvik; Lancaster Sound; Longyearbyen; Northwest Territories; Nunavut; Spitzbergen
• Online Access: https://insu.hal.science/insu-01436422; https://insu.hal.science/insu-01436422/document; https://insu.hal.science/insu-01436422/file/acp-17-8757-2017.pdf; https://doi.org/10.5194/acp-17-8757-2017

International audience Vertical distributions of atmospheric dimethyl sulfide (DMS(g)) were sampled aboard the research aircraft Polar 6 near Lancaster Sound, Nunavut, Canada, in July 2014 and on pan-Arctic flights in April 2015 that started from Longyearbyen, Spitzbergen, and passed through Alert and Eureka, Nunavut, and Inuvik, Northwest Territories. Larger mean DMS(g) mixing ratios were present during April 2015 (campaign mean of 116 ± 8 pptv) compared to July 2014 (campaign mean of 20 ± 6 pptv). During July 2014, the largest mixing ratios were found near the surface over the ice edge and open water. DMS(g) mixing ratios decreased with altitude up to about 3 km. During April 2015, profiles of DMS(g) were more uniform with height and some profiles showed an increase with altitude. DMS reached as high as 100 pptv near 2500 m.Relative to the observation averages, GEOS-Chem (www.geos-chem.org) chemical transport model simulations were higher during July and lower during April. Based on the simulations, more than 90 % of the July DMS(g) below 2 km and more than 90 % of the April DMS(g) originated from Arctic seawater (north of 66° N). During April, 60 % of the DMS(g), between 500 and 3000 m originated from Arctic seawater. During July 2014, FLEXPART (FLEXible PARTicle dispersion model) simulations locate the sampled air mass over Baffin Bay and the Canadian Arctic Archipelago 4 days back from the observations. During April 2015, the locations of the air masses 4 days back from sampling were varied: Baffin Bay/Canadian Archipelago, the Arctic Ocean, Greenland and the Pacific Ocean. Our results highlight the role of open water below the flight as the source of DMS(g) during July 2014 and the influence of long-range transport (LRT) of DMS(g) from further afield in the Arctic above 2500 m during April 2015.