Show simple item record

dc.contributor.authorZannoni, Daniele
dc.contributor.authorSteen-Larsen, Hans Christian
dc.contributor.authorPeters, A.J.
dc.contributor.authorWahl, Sonja
dc.contributor.authorSodemann, Harald
dc.contributor.authorSveinbjörnsdóttir, A.E.
dc.description.abstractOcean isotopic evaporation models, such as the Craig-Gordon model, rely on the description of nonequilibrium fractionation factors that are, in general, poorly constrained. To date, only a few gradient-diffusion type measurements have been performed in ocean settings to test the validity of the commonly used parametrization of nonequilibrium isotopic fractionation during ocean evaporation. In this work, we present 6 months of water vapor isotopic observations collected from a meteorological tower located in the northwest Atlantic Ocean (Bermuda) with the objective of estimating nonequilibrium fractionation factors (k, ‰) for ocean evaporation and their wind speed dependency. The Keeling Plot method and Craig-Gordon model combination were sensitive enough to resolve nonequilibrium fractionation factors during evaporation resulting into mean values of k18 = 5.2 ± 0.6‰ and k2 = 4.3 ± 3.4‰. Furthermore, we evaluate the relationship between k and 10-m wind speed over the ocean. Such a relationship is expected from current evaporation theory and from laboratory experiments made in the 1970s, but observational evidence is lacking. We show that (a) in the observed wind speed range [0–10 m s−1], the sensitivity of k to wind speed is small, in the order of −0.2‰ m−1 s for k18, and (b) there is no empirical evidence for the presence of a discontinuity between smooth and rough wind speed regime during isotopic fractionation, as proposed in earlier studies. The water vapor d-excess variability predicted under the closure assumption using the k values estimated in this study is in agreement with observations over the Atlantic Ocean.en_US
dc.publisherAmerican Geophysical Unionen_US
dc.rightsNavngivelse 4.0 Internasjonal*
dc.titleNon-Equilibrium Fractionation Factors for D/H and 18O/16O During Oceanic Evaporation in the North-West Atlantic Regionen_US
dc.typeJournal articleen_US
dc.typePeer revieweden_US
dc.rights.holderCopyright 2022 the authorsen_US
dc.source.journalJournal of Geophysical Research (JGR): Atmospheresen_US
dc.identifier.citationJournal of Geophysical Research (JGR): Atmospheres. 2022, 127 (21), e2022JD037076.en_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

Navngivelse 4.0 Internasjonal
Except where otherwise noted, this item's license is described as Navngivelse 4.0 Internasjonal