Evidence for the uptake of atmospheric acetone and methanol by the Arctic Ocean during late summer DMS-Emission plumes

Abstract

Mixing ratios of gas-phase dimethyl sulfide (DMS), acetone and methanol were measured for the first time in the Canadian Archipelago using a proton-transfer-reaction mass spectrometer (PTR-MS) onboard the CCGS Amundsen from 23 August 2008 to 12 September 2008. For the entire measurement period, there existed moderate negative correlations between both acetone (R = 0.37, p < 10<sup>-4) and methanol (R = 0.26, p < 10<sup>-4) with DMS. When elevated DMS mixing ratios were observed on a transect between Kugaaruk and Resolute, during which elevated oceanic DMS was also observed, the anticorrelations of acetone and methanol mixing ratios with DMS were stronger (R = 0.61, p < 10<sup>-4 and 0.45, p < 10<sup>-4 respectively). There were no significant correlations of the aromatic species (benzene and toluene) with DMS, and the relatively low values of benzene (mean = 12 pptv) and toluene (mean = 4 pptv) indicate little significant local or regional influence of anthropogenic sources on these observations. When the recent air parcel history was predominantly of marine influence, the DMS mixing ratios were positively correlated with wind speed whereas acetone and methanol were negatively correlated. These observations suggest that biologically active waters in the high Arctic act as a sink for acetone and methanol. While speculative, continued changes in the Arctic climate have the potential to affect levels of acetone and methanol in the polar atmosphere, either through increased levels of open ocean or increased biological productivity. © 2012 American Geophysical Union. All Rights Reserved.