Mardi 24 janvier - Regional ocean-atmosphere interactions and biogeochemical activity
de 11:00 à 12:00
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Lionel Renault, research assistant, Department of Atmospheric and Oceanic Sciences, UCLA Los Angeles
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Research assistant, Department of Atmospheric and Oceanic Sciences (AOS), University of California, Los Angeles (UCLA)
Titre : Regional Ocean-Atmosphere Interactions and their Consequences on the Circulation and on the Biogeochemical Activity
The Ocean - Atmosphere interactions have a large influence on the climate and on the ecosystems at the basin scale. The main climatic modes of variability (e.g., El Nino, NAO, ...) are coupled modes between the Ocean and the Atmosphere. The ecosystems have a strong response to those variations through the influence of the wind, the light, and the temperature on the nutrient stock and, thus, on the primary production and the oxygen concentration.
Systematic biases in sea surface temperature in global models have highlighted the limitations of studies based on the global models and have, thus, spurred the investigation of the Ocean-Atmosphere interactions based on the regional modelling approach.
In the past few years, it has been demonstrated that the regional Ocean-Atmosphere interactions can strongly modulate the variability and the mean physical and biogeochemical state of the ocean.
In this presentation, the focus will be on two processes involving Ocean-Atmosphere interactions: the wind stress curl forcing associated to the so-called wind drop-off and the current feedback to the atmosphere. Using a set of regional coupled Ocean and Atmosphere models over different regions encompassing Eastern and Western boundary current systems, we will illustrate to which extent those interactions can control the exchange of energy between the Ocean and the Atmosphere, the mean and meso-scale circulations, and the net primary production and oxygen concentration. Implication of these results for understanding the deoxygenation of the ocean and the impact of climate change on the Eastern Boundary Upwelling System will be discussed