New insights into aerosol and climate in the Arctic

• Main Authors: Abbatt, J., Leaitch, W., Aliabadi, A., Bertram, A., Blanchet, J., Boivin-Rioux, A., Bozem, H., Burkart, J., Chang, R., Charette, J., Chaubey, J., Christensen, R., Cirisan, A., Collins, D., Croft, B., Dionne, J., Evans, G., Fletcher, C., Ghahremaninezhad, R., Girard, E., Gong, W., Gosselin, M., Gourdal, M., Hanna, S., Hayashida, H., Herber, A., Hesaraki, S., Hoor, P., Huang, L., Hussherr, R., Irish, V., Keita, S., Kodros, J., Köllner, F., Kolonjari, F., Kunkel, D., Ladino, L., Law, K., Levasseur, M., Libois, Q., Liggio, J., Lizotte, M., Macdonald, K., Mahmood, R., Martin, R., Mason, R., Miller, L., Moravek, A., Mortenson, E., Mungall, E., Murphy, J., Namazi, M., Norman, A., O'Neill, N., Pierce, J., Russell, L., Schneider, J., Schulz, H., Sharma, S., Si, M., Staebler, R., Steiner, N., Gali, M., Thomas , J., Von Salzen, K., Wentzell, J., Willis, M., Wentworth, G., Xu, J., Yakobi-Hancock, J.
• Format: Report
• Language: English
• Published: 2018
• Subjects: Arctic; Canadian Arctic Archipelago; Arctic Archipelago; black carbon; Tundra
• Online Access: http://hdl.handle.net/21.11116/0000-0003-0F0B-2

Motivated by the need to predict how the Arctic atmosphere will change in a warming world, this article summarizes recent advances made by the research consortium NETCARE (Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments) that contribute to our fundamental understanding of Arctic aerosol particles as they relate to climate forcing. The overall goal of NETCARE research has been to use an interdisciplinary approach encompassing extensive field observations and a range of chemical transport, earth system, and biogeochemical models. Several major findings and advances have emerged from NETCARE since its formation in 2013 . (1) Unexpectedly high summertime dimethyl sulfide (DMS) levels were identified in ocean water and the overlying atmosphere in the Canadian Arctic Archipelago (CAA). Furthermore, melt ponds, which are widely prevalent, were identified as an important DMS source. (2) Evidence was found of widespread particle nucleation and growth in the marine boundary layer in the CAA in the summertime. DMS-oxidation-driven nucleation is facilitated by the presence of atmospheric ammonia arising from sea bird colony emissions, and potentially also from coastal regions, tundra, and biomass burning. Via accumulation of secondary organic material (SOA), a significant fraction of the new particles grow to sizes that are active in cloud droplet formation. Although the gaseous precursors to Arctic marine SOA remain poorly defined, the measured levels of common continental SOA precursors (isoprene and monoterpenes) were low, whereas elevated mixing ratios of oxygenated volatile organic compounds were inferred to arise via processes involving the sea surface microlayer. (3) The variability in the vertical distribution of black carbon (BC) under both springtime Arctic haze and more pristine summertime aerosol conditions was observed. Measured particle size distributions and mixing states were used to constrain, for the first time, calculations of aerosol–climate interactions ...