Methanol, acetaldehyde, and acetone in the surface waters of the Atlantic Ocean. Issue 10 (16th October 2013)

• Record Type: Journal Article
• Authors: Beale, Rachael; Dixon, Joanna L.; Arnold, Steve R.; Liss, Peter S.; Nightingale, Philip D.
• Is Part Of: Journal of geophysical research. Volume 118:Issue 10(2013:Oct.)
• Page Start: 5412
• Page End: 5425
• Publication Date: 2013-10-16
• Subjects: Oceanography -- Periodicals; 551.4605
• DOI: 10.1002/jgrc.20322
• Languages: English
• ISSNs: 2169-9275

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>[1] Oceanic methanol, acetaldehyde, and acetone concentrations were measured during an Atlantic Meridional Transect (AMT) cruise from the UK to Chile (49°N to 39°S) in 2009. Methanol (48–361 n<italic>M</italic>) and acetone (2–24 n<italic>M</italic>) varied over the track with enrichment in the oligotrophic Northern Atlantic Gyre. Acetaldehyde showed less variability (3–9 n<italic>M</italic>) over the full extent of the transect. These oxygenated volatile organic compounds (OVOCs) were also measured subsurface, with methanol and acetaldehyde mostly showing homogeneity throughout the water column. Acetone displayed a reduction below the mixed layer. OVOC concentrations did not consistently correlate with primary production or chlorophyll‐a levels in the surface Atlantic Ocean. However, we did find a novel and significant negative relationship between acetone concentration and bacterial leucine incorporation, suggesting that acetone might be removed by marine bacteria as a source of carbon. Microbial turnover of both acetone and acetaldehyde was confirmed. Modeled atmospheric data are used to estimate the likely air‐side OVOC concentrations. The direction and magnitude of air‐sea fluxes vary for all three OVOCs depending on location. We present evidence that the ocean may exhibit regions of acetaldehyde under‐saturation. Extrapolation suggests that the Atlantic Ocean represents an overall source of these OVOCs to the atmosphere at 3, 3, and 1 Tg yr<sup>−1</sup> for methanol, acetaldehyde, and acetone, respectively.</p> </abstract>