The SOLAS Bergen Mesocosm Experiment 2008: The Role of the Sea Surface Microlayer in Air-Sea Gas Exchange.
Abstract
During the UKSOLAS "Joint Bergen Mesocosm Experiment" we investigated the role of microbial processes in the sea surface microlayer (SML) in controlling the production, consumption and sea-to-air fluxes of methane and nitrous oxide during the development of a phytoplankton bloom. In mesocosm waters transferred to a purpose-built sealed gas exchange tank, we measured invasive and evasive exchange fluxes of methane, nitrous oxide and inert sulphur hexafluoride at selected levels of turbulence using a fully automated, coupled gas chromatographic (GC) system. From the measured fluxes we derived estimates of the so-called "apparent" gas transfer velocity, kw, normalised to a Schmidt Number (Sc) of 600 (k600). In the case where neither methane nor nitrous oxide undergoes measurable microbial cycling in the microlayer, the ratios of k600 for either methane or nitrous oxide to k600 for sulphur hexafluoride should equal unity. Significant deviations from unity thus enable us to infer and quantify any microbial modification of gas exchange rates in the microlayer.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.B31B0293H
- Keywords:
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- 0490 Trace gases;
- 4504 Air/sea interactions (0312;
- 3339);
- 4840 Microbiology and microbial ecology (0465)