On the sensitivity of Antarctic sea ice model biases to atmospheric forcing uncertainties
Barthelemy, A.; Goosse, H.; Fichefet, T.; Lecomte, O. (2018). On the sensitivity of Antarctic sea ice model biases to atmospheric forcing uncertainties. Clim. Dyn. 51(4): 1585-1603. https://dx.doi.org/10.1007/s00382-017-3972-7 In: Climate Dynamics. Springer: Berlin; Heidelberg. ISSN 0930-7575; e-ISSN 1432-0894, more |  |
| Keyword | | | Author keywords | Sea ice; Antarctic; Model; Atmospheric forcing; Uncertainties |
| Abstract | Although atmospheric reanalyses are an extremely valuable tool to study the climate of polar regions, they suffer from large uncertainties in these data-poor areas. In this work, we examine how Antarctic sea ice biases in an ocean-sea ice model are related to these forcing uncertainties. Three experiments are conducted in which the NEMO-LIM model is driven by different atmospheric forcing sets. The minimum ice extent, the ice motion and the ice thickness are sensitive to the reanalysis chosen to drive the model, while the wintertime ice extent and inner pack concentrations are barely affected. The analysis of sea ice concentration budgets allows identifying the processes leading to differences between the experiments, and also indicates that large and similar errors compared to observations are present in all three cases. Our assessment of the influence of forcing inaccuracies on the simulated Antarctic sea ice allows disentangling two types of model biases: the ones that can be reduced thanks to better atmospheric forcings, and those that would require improvements of the physics of the ice or ocean model. |
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