Description du projet
Mesurer les impacts quantifiables sur la science du climat
Chaque année, l’océan Austral est responsable de plus de 60 % de la chaleur excédentaire associée au changement climatique anthropique absorbée par les océans du monde entier. En contrôlant les échanges de chaleur et de carbone entre l’atmosphère et les océans, il régule le climat mondial. Nous savons cependant peu de choses sur les processus sous‑jacents. Afin de contribuer à réduire les incertitudes dans les prévisions du changement climatique, le projet SO-CHIC, financé par l’UE, quantifiera la variabilité des «budgets chaleur et carbone» de l’océan Austral en étudiant les processus clés qui contrôlent les échanges entre l’atmosphère, l’océan et la glace de mer, en combinant des approches d’observation et de modélisation. Il combinera l’observation avec des séries chronologiques existantes sur plusieurs décennies et la modélisation de pointe.
Objectif
The Southern Ocean regulates the global climate by controlling heat and carbon exchanges between the atmosphere and the ocean. It is responsible for about 60-90% of the excess heat (i.e. associated with anthropogenic climate change) absorbed by the World Oceans each year, and is also recognised to largely control decadal scale variability of Earth carbon budget, with key implications for decision makers and regular global stocktake agreed as part of the Paris agreement. Despite such pivotal climate importance, its representation in global climate model represents one of the main weaknesses of climate simulation and projection because too little is known about the underlying processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent small-scale processes that are not captured in current Earth system models. The overall objective of SO-CHIC is to understand and quantify variability of heat and carbon budgets in the Southern Ocean through an investigation of the key processes controlling exchanges between the atmosphere, ocean and sea ice using a combination of observational and modelling approaches. SO-CHIC considers the Atlantic sector of the Southern Ocean as a natural laboratory both because of its worldwide importance in water-mass formation and because of the strong European presence in this sector already established at national levels, which allow to best leverage existing expertise, infrastructure, and observation network, around one single coordinated overall objective. SO-CHIC also takes the opportunity of the recent re-appearance of the Atlantic Sector Weddell Polynya to unveil its dynamics and global impact on heat and carbon cycles. A combination of dedicated observation, existing decades-long time-series, and state-of-the-art modelling will be used to address specific objectives on key processes, as well as their impact and feedback on the large-scale atmosphere-ocean system.
Champ scientifique
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RIA - Research and Innovation actionCoordinateur
75006 Paris
France