Nitrous oxide variability at sub-kilometre resolution in the Atlantic sector of the Southern Ocean

Grefe, Imke, Fielding, Sophie, Heywood, Karen J. and Kaiser, Jan (2018) Nitrous oxide variability at sub-kilometre resolution in the Atlantic sector of the Southern Ocean. PeerJ, 6. ISSN 2167-8359

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Abstract

The Southern Ocean is an important region for global nitrous oxide (N2O) cycling. The contribution of different source and sink mechanisms is, however, not very well constrained due to a scarcity of seawater data from the area. Here we present high-resolution surface N2O measurements from the Atlantic sector of the Southern Ocean, taking advantage of a relatively new underway setup allowing for collection of data during transit across mesoscale features such as frontal systems and eddies. Covering a range of different environments and biogeochemical settings, N2O saturations and sea-to-air fluxes were highly variable: Saturations ranged from 96.5% at the sea ice edge in the Weddell Sea to 126.1% across the Polar Frontal Zone during transit to South Georgia. Negative sea-to-air fluxes (N2O uptake) of up to −1.3 µmol m−2 d−1 were observed in the Subantarctic Zone and highest positive fluxes (N2O emission) of 14.5 µmol m−2 d−1 in Stromness Bay, coastal South Georgia. Although N2O saturations were high in areas of high productivity, no correlation between saturations and chlorophyll a (as a proxy for productivity) was observed. Nevertheless, there is a clear effect of islands and shallow bathymetry on N2O production as inferred from supersaturations.

Item Type: Article
Uncontrolled Keywords: nitrous oxide,southern ocean,high-resolution measurements,air-sea gas exchange,marine biogeochemistry,laser spectroscopy
Faculty \ School: Faculty of Science > School of Environmental Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 06 Jul 2018 12:30
Last Modified: 22 Apr 2020 06:48
URI: https://ueaeprints.uea.ac.uk/id/eprint/67543
DOI: 10.7717/peerj.5100

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