Deuterium excess in marine water vapor: Dependency on relative humidity and surface wind speed during evaporation - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research: Atmospheres Année : 2014

Deuterium excess in marine water vapor: Dependency on relative humidity and surface wind speed during evaporation

Résumé

We provide the first continuous measurements of isotopic composition (δD and δ18O) of water vapor over the subtropical Eastern North Atlantic Ocean from mid-August to mid-September 2012. The ship was located mostly around 26°N, 35°W where evaporation exceeded by far precipitation and water vapor at 20 m largely originated from surface evaporation. The only large deviations from that occurred during a 2 day period in the vicinity of a weak low-pressure system. The continuous measurements were used to investigate deuterium excess (d-excess) relation to evaporation. During 25 days d-excess was negatively correlated with relative humidity (r2 = 0.89). Moreover, d-excess estimated in an evaporative model with a closure assumption reproduced most of the observed variability. From these observations, the d-excess parameter seems to be a good indicator of evaporative conditions. We also conclude that in this region, d-excess into the marine boundary layer is less affected by mixing with the free troposphere than the isotopic composition. From our data, the transition from smooth to rough regime at the ocean surface is associated with a d-excess decrease of 5‰, which suggests the importance of the ocean surface roughness in controlling d-excess in this region.
Fichier principal
Vignette du fichier
2013JD020535.pdf (3.95 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-00979248 , version 1 (28-10-2020)

Identifiants

Citer

Marion Benetti, Gilles Reverdin, Catherine Pierre, Liliane Merlivat, Camille Risi, et al.. Deuterium excess in marine water vapor: Dependency on relative humidity and surface wind speed during evaporation. Journal of Geophysical Research: Atmospheres, 2014, 119, pp.584-593. ⟨10.1002/2013JD020535⟩. ⟨hal-00979248⟩
213 Consultations
124 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More