ISSN:
1573-0662
Keywords:
Surface microlayer
;
ocean-atmosphere interface
;
gas flux
;
H2
;
CO
;
CH4
;
N2O
;
troposphere
;
stagnant film model
;
bacterio-neuston
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
Abstract Gas exchange experiments were conducted in the tropical Atlantic Ocean during a ship expedition with FS Meteor using a small rubber raft. The temporal change of the mixing ratios of CO, H2, CH4 and N2O in the headspace of a floating glass box and the concentrations of these gases in the water phase were measured to determine their transfer velocities across the ocean-atmosphere interface. The ocean acted as a sink for these gases when the water was undersaturated with respect to the mixing ratio in the headspace. The transfer velocities were different for the individual gases and showed still large differences even when normalized for diffusivity. Applying the laminar film model, film thicknesses of 20 to 70 μm were calculated for the observed flux rates of the different gas species. When the water was supersaturated with respect to atmospheric CO, H2, CH4 and N2O, the transfer velocities of the emission process were smaller than those determined for the deposition process. In case of H2 and CH4, emission was even not calculable although, based on the observed gradient, the laminar film model predicted significant fluxes at the air-sea interface. The results are interpreted by destruction processes active within the surface microlayer.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00048333
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