Pan-derived isotopic composition of atmospheric vapour in a Mediterranean wetland (Rhône River Delta, France).
A continuous record of atmospheric vapour isotopic composition (delta(A)) can be derived from the isotope mass balance of a water body submitted to natural evaporation. In this paper, we present preliminary results of the application of this method to a drying evaporation pan, located in a Mediterranean wetland, during a two-month summer period. Results seem consistent with few atmospheric vapour data based on the assumption of isotopic equilibrium with precipitation, but we observed a shift between pan-derived delta(A) and the composition of vapour samples collected by cold trapping. These results suggest that further investigations are necessary to evaluate the effect of diurnal variations of atmospheric conditions on the applicability of the pan-evaporation method, and on the representative of grab atmospheric samples. We also propose a sensitivity analysis for evaluating the impact of the different measured components on delta(A) calculation, and show an improvement in the method efficiency as the pan is drying.
Vallet-Coulomb
Christine
C
CEREGE, Aix-Marseille Universite, UMR 6635 CNRS-IRD-CDF, Europole Mediterraneen de l'Arbois, Aix en Provence, France. vallet@cerege.fr
Cartapanis
Olivier
O
Radakovitch
Olivier
O
Sonzogni
Corinne
C
Pichaud
Marc
M
D001272:Atmosphere / Q000737:chemistry*; D003903:Deuterium / Q000032:analysis*; D004784:Environmental Monitoring; D005602:France; D005740:Gases / Q000032:analysis*; D005843:Geography; D006813:Humidity; D019083:Mediterranean Region; D010103:Oxygen Isotopes / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014835:Volatilization; D053833:Wetlands
D005740:Gases; D010103:Oxygen Isotopes; D003903:Deuterium