Control and Stabilization of the Gulf Stream by Oceanic Current Interaction with the Atmosphere - Archive ouverte HAL
Article Dans Une Revue Journal of Physical Oceanography Année : 2016

Control and Stabilization of the Gulf Stream by Oceanic Current Interaction with the Atmosphere

Résumé

The Gulf Stream (GS) is known to have a strong influence on climate, for example, by transporting heat from the tropics to higher latitudes. Although the GS transport intensity presents a clear interannual variability, satellite observations reveal its mean path is stable. Numerical models can simulate some characteristics of the mean GS path, but persistent biases keep the GS separation and postseparation unstable and therefore unrealistic. This study investigates how the integration of ocean surface currents into the ocean–atmosphere coupling interface of numerical models impacts the GS. The authors show for the first time that the current feedback, through its eddy killing effect, stabilizes the GS separation and postseparation, resolving long-lasting biases in modeled GS path, at least for the Regional Oceanic Modeling System (ROMS). This key process should therefore be taken into account in oceanic numerical models. Using a set of oceanic and atmospheric coupled and uncoupled simulations, this study shows that the current feedback, by modulating the energy transfer from the atmosphere to the ocean, has two main effects on the ocean. On one hand, by reducing the mean surface stress and thus weakening the mean geostrophic wind work by 30%, the current feedback slows down the whole North Atlantic oceanic gyre, making the GS narrower and its transport weaker. Yet, on the other hand, the current feedback acts as an oceanic eddy killer, reducing the surface eddy kinetic energy by 27%. By inducing a surface stress curl opposite to the current vorticity, it deflects energy from the geostrophic current into the atmosphere and dampens eddies.
Fichier principal
Vignette du fichier
1520-0485-jpo-d-16-0115.1.pdf (2.69 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-01498553 , version 1 (23-02-2023)

Identifiants

Citer

Lionel Renault, M. Jeroen Molemaker, Jonathan Gula, Sébastien Masson, James C. Mcwilliams. Control and Stabilization of the Gulf Stream by Oceanic Current Interaction with the Atmosphere. Journal of Physical Oceanography, 2016, 46 (11), pp.3439 - 3453. ⟨10.1175/jpo-d-16-0115.1⟩. ⟨hal-01498553⟩
129 Consultations
22 Téléchargements

Altmetric

Partager

More