Publications des scientifiques de l'IRD

Silvy Y., Rousset C., Guilyardi E., Sallee J. B., Mignot Juliette, Ethe C., Madec G. (2022). A modeling framework to understand historical and projected ocean climate change in large coupled ensembles. Geoscientific Model Development, 15 (20), p. 7683-7713. ISSN 1991-959X.

Titre du document
A modeling framework to understand historical and projected ocean climate change in large coupled ensembles
Année de publication
2022
Type de document
Article référencé dans le Web of Science WOS:000870707500001
Auteurs
Silvy Y., Rousset C., Guilyardi E., Sallee J. B., Mignot Juliette, Ethe C., Madec G.
Source
Geoscientific Model Development, 2022, 15 (20), p. 7683-7713 ISSN 1991-959X
The ocean responds to climate change through modifications of heat, freshwater and momentum fluxes at its boundaries. Disentangling the specific role of each of these contributors in shaping the changes of the thermohaline structure of the ocean is central for our process understanding of climate change and requires the design of specific numerical experiments. While it has been partly addressed by modeling studies using idealized CO2 forcings, the time evolution of these individual contributions during historical and projected climate change is however lacking. Here, we propose a novel modeling framework to isolate these contributions in coupled climate models for which large ensembles of historical and scenario simulations are available. The first step consists in reproducing a coupled pre-industrial control simulation with an ocean-only configuration, forced by prescribed fluxes at its interface, diagnosed from the coupled model. In a second step, we extract the external forcing perturbations from the historical+ scenario ensemble of coupled simulations, and we add them to the prescribed fluxes of the ocean-only configuration. We then successfully replicate the ocean's response to historical and projected climate change in the coupled model during 1850-2100. In a third step, this full response is decomposed in sensitivity experiments in which the forcing perturbations are applied individually to the heat, freshwater and momentum fluxes. Passive tracers of temperature and salinity are implemented to discriminate the addition of heat and freshwater flux anomalies from the redistribution of pre-industrial heat and salt content in response to ocean circulation changes. Here, we first present this general framework and then apply it to the IPSL-CM6A-LR model and its ocean component NEMO3.6. This framework brings new opportunities to precisely explore the mechanisms driving historical and projected ocean changes within single climate models.
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 B010086366]
Identifiant IRD
PAR00025138
Contact