Journal of Atmospheric Chemistry

, Volume 6, Issue 1, pp 83–94

Influence of the surface microlayer on the flux of nonconservative trace gases (CO, H2, CH4, N2O) across the ocean-atmosphere interface

  • Ralf Conrad
  • Wolfgang Seiler
Influence of Marine and Terrestrial Biosphere on the Chemical Composition of the Atmosphere

DOI: 10.1007/BF00048333

Cite this article as:
Conrad, R. & Seiler, W. J Atmos Chem (1988) 6: 83. doi:10.1007/BF00048333


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.

Key words

Surface microlayerocean-atmosphere interfacegas fluxH2COCH4N2Otropospherestagnant film modelbacterio-neuston

Copyright information

© D. Reidel Publishing Company 1988

Authors and Affiliations

  • Ralf Conrad
    • 1
  • Wolfgang Seiler
    • 1
  1. 1.Max-Planck-Institut für ChemieMainzF.R. Germany
  2. 2.Fakultät für BjologieUniversität KonstanzKonstanz 1F.R.G.
  3. 3.Fraunhofer Institut für Atmosphärische UmweltforschungGarmisch-PartenkirchenF.R.G.