Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 6665-6680, 2016
https://doi.org/10.5194/acp-16-6665-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
02 Jun 2016
Dimethyl sulfide in the summertime Arctic atmosphere: measurements and source sensitivity simulations
Emma L. Mungall1, Betty Croft2, Martine Lizotte3, Jennie L. Thomas4, Jennifer G. Murphy1, Maurice Levasseur3, Randall V. Martin2, Jeremy J. B. Wentzell5, John Liggio5, and Jonathan P. D. Abbatt1 1Department of Chemistry, University of Toronto, Toronto, Canada
2Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada
3Québec-Océan, Department of Biology, Université Laval, Québec, Canada
4Sorbonne Universités, UPMC Univ. Paris 06, Université Versailles St-Quentin, CNRS/INSU, LATMOS-IPSL, Paris, France
5Air Quality Processes Research Section, Environment Canada, Toronto, Ontario, Canada
Abstract. Dimethyl sulfide (DMS) plays a major role in the global sulfur cycle. In addition, its atmospheric oxidation products contribute to the formation and growth of atmospheric aerosol particles, thereby influencing cloud condensation nuclei (CCN) populations and thus cloud formation. The pristine summertime Arctic atmosphere is strongly influenced by DMS. However, atmospheric DMS mixing ratios have only rarely been measured in the summertime Arctic. During July–August, 2014, we conducted the first high time resolution (10 Hz) DMS mixing ratio measurements for the eastern Canadian Archipelago and Baffin Bay as one component of the Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments (NETCARE). DMS mixing ratios ranged from below the detection limit of 4 to 1155 pptv (median 186 pptv) during the 21-day shipboard campaign. A transfer velocity parameterization from the literature coupled with coincident atmospheric and seawater DMS measurements yielded air–sea DMS flux estimates ranging from 0.02 to 12 µmol m−2 d−1. Air-mass trajectory analysis using FLEXPART-WRF and sensitivity simulations with the GEOS-Chem chemical transport model indicated that local sources (Lancaster Sound and Baffin Bay) were the dominant contributors to the DMS measured along the 21-day ship track, with episodic transport from the Hudson Bay System. After adjusting GEOS-Chem oceanic DMS values in the region to match measurements, GEOS-Chem reproduced the major features of the measured time series but was biased low overall (2–1006 pptv, median 72 pptv), although within the range of uncertainty of the seawater DMS source. However, during some 1–2 day periods the model underpredicted the measurements by more than an order of magnitude. Sensitivity tests indicated that non-marine sources (lakes, biomass burning, melt ponds, and coastal tundra) could make additional episodic contributions to atmospheric DMS in the study region, although local marine sources of DMS dominated. Our results highlight the need for both atmospheric and seawater DMS data sets with greater spatial and temporal resolution, combined with further investigation of non-marine DMS sources for the Arctic.

Citation: Mungall, E. L., Croft, B., Lizotte, M., Thomas, J. L., Murphy, J. G., Levasseur, M., Martin, R. V., Wentzell, J. J. B., Liggio, J., and Abbatt, J. P. D.: Dimethyl sulfide in the summertime Arctic atmosphere: measurements and source sensitivity simulations, Atmos. Chem. Phys., 16, 6665-6680, https://doi.org/10.5194/acp-16-6665-2016, 2016.
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Previous work has suggested that marine emissions of dimethyl sulfide (DMS) could impact the Arctic climate through interactions with clouds. We made the first high-time-resolution measurements of summertime atmospheric DMS in the Canadian Arctic, and performed source sensitivity simulations. We found that regional marine sources dominated, but do not appear to be sufficient to explain our observations. Understanding DMS sources in the Arctic is necessary to model future climate in the region.
Previous work has suggested that marine emissions of dimethyl sulfide (DMS) could impact the...
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