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Séférian R., Bopp L., Gehlen M., Orr J. C., Ethe C., Cadule P., Aumont Olivier, Melia D. S. Y., Voldoire A., Madec G. (2013). Skill assessment of three earth system models with common marine biogeochemistry. In : Presentation and analysis of the IPSL and CNRM climate models used in CMIP5. Climate Dynamics, 40 (9-10), p. 2549-2573. ISSN 0930-7575.

Titre du document
Skill assessment of three earth system models with common marine biogeochemistry
Année de publication
2013
Type de document
Article référencé dans le Web of Science WOS:000318278700023
Auteurs
Séférian R., Bopp L., Gehlen M., Orr J. C., Ethe C., Cadule P., Aumont Olivier, Melia D. S. Y., Voldoire A., Madec G.
In
Presentation and analysis of the IPSL and CNRM climate models used in CMIP5
Source
Climate Dynamics, 2013, 40 (9-10), p. 2549-2573 ISSN 0930-7575
We have assessed the ability of a common ocean biogeochemical model, PISCES, to match relevant modern data fields across a range of ocean circulation fields from three distinct Earth system models: IPSL-CM4-LOOP, IPSL-CM5A-LR and CNRM-CM5.1. The first of these Earth system models has contributed to the IPCC 4th assessment report, while the latter two are contributing to the ongoing IPCC 5th assessment report. These models differ with respect to their atmospheric component, ocean subgrid-scale physics and resolution. The simulated vertical distribution of biogeochemical tracers suffer from biases in ocean circulation and a poor representation of the sinking fluxes of matter. Nevertheless, differences between upper and deep ocean model skills significantly point to changes in the underlying model representations of ocean circulation. IPSL-CM5A-LR and CNRM-CM5.1 poorly represent deep-ocean circulation compared to IPSL-CM4-LOOP degrading the vertical distribution of biogeochemical tracers. However, their representations of surface wind, wind stress, mixed-layer depth and geostrophic circulations (e.g., Antarctic Circumpolar Current) have been improved compared to IPSL-CM4-LOOP. These improvements result in a better representation of large-scale structure of biogeochemical fields in the upper ocean. In particular, a deepening of 20-40 m of the summer mixed-layer depth allows to capture the 0-0.5 mu gChl L-1 concentrations class of surface chlorophyll in the Southern Ocean. Further improvements in the representation of the ocean mixed-layer and deep-ocean ventilation are needed for the next generations of models development to better simulate marine biogeochemistry. In order to better constrain ocean dynamics, we suggest that biogeochemical or passive tracer modules should be used routinely for both model development and model intercomparisons.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du milieu [021] ; Limnologie physique / Océanographie physique [032]
Localisation
Fonds IRD [F B010060871]
Identifiant IRD
fdi:010060871
Contact