Relationships linking primary production, sea ice melting, and biogenic aerosol in the Arctic

• Published in: Atmospheric Environment
• Main Authors: Pace, G., Meloni, D., di Sarra, A., Di Iorio, T., Di Biagio, C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Ltd 2016
• Subjects: Marginal sea ice; Chlorophyll; MSA; Arctic; Sea ice melting; Primary production; Baffin Bay; Baffin; Barents Sea; Greenland; Greenland Sea; Sea ice; Svalbard; Thule Air; Thule Air Base; Thule
• Online Access: https://hdl.handle.net/20.500.12079/3088; https://doi.org/10.1016/j.atmosenv.2016.04.002; https://www.scopus.com/inward/record.url?eid=2-s2.0-84963650319&partnerID=40&md5=bbadf33590267d0d993bea70a129a369

This study examines the relationships linking methanesulfonic acid (MSA, arising from the atmospheric oxidation of the biogenic dimethylsulfide, DMS) in atmospheric aerosol, satellite-derived chlorophyll a (Chl-a), and oceanic primary production (PP), also as a function of sea ice melting (SIM) and extension of the ice free area in the marginal ice zone (IF-MIZ) in the Arctic. MSA was determined in PM10 samples collected over the period 2010-2012 at two Arctic sites, Ny Ålesund (78.9°N, 11.9°E), Svalbard islands, and Thule Air Base (76.5°N, 68.8°W), Greenland. PP is calculated by means of a bio-optical, physiologically based, semi-analytical model in the potential source areas located in the surrounding oceanic regions (Barents and Greenland Seas for Ny Ålesund, and Baffin Bay for Thule). Chl-a peaks in May in the Barents sea and in the Baffin Bay, and has maxima in June in the Greenland sea; PP follows the same seasonal pattern of Chl-a, although the differences in absolute values of PP in the three seas during the blooms are less marked than for Chl-a. MSA shows a better correlation with PP than with Chl-a, besides, the source intensity (expressed by PP) is able to explain more than 30% of the MSA variability at the two sites; the other factors explaining the MSA variability are taxonomic differences in the phytoplanktonic assemblages, and transport processes from the DMS source areas to the sampling sites. The taxonomic differences are also evident from the slopes of the correlation plots between MSA and PP: similar slopes (in the range 34.2-36.2 ng m-3of MSA/(gC m-2 d-1)) are found for the correlation between MSA at Ny Ålesund and PP in Barents Sea, and between MSA at Thule and PP in the Baffin Bay; conversely, the slope of the correlation between MSA at Ny Ålesund and PP in the Greenland Sea in summer is smaller (16.7 ng m-3of MSA/(gC m-2 d-1)). This is due to the fact that DMS emission from the Barents Sea and Baffin Bay is mainly related to the MIZ diatoms, which are prolific DMS producers, whereas in ...