δ18O water isotope in the iLOVECLIM model (version 1.0) – Part 2: Evaluation of model results against observed δ18O in water samples

• Published in: Geoscientific Model Development
• Main Authors: Roche, D. M., Caley, T.
• Format: Text
• Language: English
• Published: 2018
• Subjects: Antarc*; Antarctica
• Online Access: https://doi.org/10.5194/gmd-6-1493-2013; https://gmd.copernicus.org/articles/6/1493/2013/

The H 2 18 O stable isotope was previously introduced in the three coupled components of the earth system model i LOVECLIM: atmosphere, ocean and vegetation. The results of a long (5000 yr) pre-industrial equilibrium simulation are presented and evaluated against measurement of H 2 18 O abundance in present-day water for the atmospheric and oceanic components. For the atmosphere, it is found that the model reproduces the observed spatial distribution and relationships to climate variables with some merit, though limitations following our approach are highlighted. Indeed, we obtain the main gradients with a robust representation of the Rayleigh distillation but caveats appear in Antarctica and around the Mediterranean region due to model limitation. For the oceanic component, the agreement between the modelled and observed distribution of water δ 18 O is found to be very good. Mean ocean surface latitudinal gradients are faithfully reproduced as well as the mark of the main intermediate and deep water masses. This opens large prospects for the applications in palaeoclimatic context.