Enhanced upward heat transport at deep submesoscale ocean fronts

• Published in: Nature Geoscience
• Main Authors: Siegelman, Lia, Klein, Patrice, Riviere, Pascal, Thompson, Andrew F., Torres, Hector S., Flexas, Mar, Menemenlis, Dimitris
• Other Authors: Department of Environmental Science and Engineering Pasadena (ESE), California Institute of Technology (CALTECH), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), SNO-MEMO, CNES-TOSCA project, Laboratoire d'Excellence LabexMER ANR-10-LABX-19, CNES-Region Bretagne doctoral grant, NASA-CNES SWOT mission, NASA Senior NPP Fellowship, David and Lucille Packard FoundationThe David and Lucile Packard Foundation, NASANational Aeronautics and Space Administration (NASA) NNX16AG42G, NNX15AG42G, French Polar Institute 109, 1201, National Aeronautics and Space Administration (NASA)National Aeronautics and Space Administration (NASA), CNES (OSTST-OSIW), ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), ANR-17-EURE-0015,ISBlue,Interdisciplinary Graduate School for the Blue planet(2017)
• Format: Article in Journal/Newspaper
• Language: English
• Published: CCSD 2020
• Subjects: SIZE LYAPUNOV EXPONENTS; BAROCLINIC INSTABILITY; SEA; MESOSCALE; ALTIMETRY; RESTRATIFICATION; ACL; [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; The Antarctic; Antarc*
• Online Access: https://hal.science/hal-02933393; https://hal.science/hal-02933393v1/document; https://hal.science/hal-02933393v1/file/Siegelman_etal_NG_2020.pdf; https://doi.org/10.1038/s41561-019-0489-1

International audience The ocean is the largest solar energy collector on Earth. The amount of heat it can store is modulated by its complex circulation, which spans a broad range of spatial scales, from metres to thousands of kilometres. In the classical paradigm, fine oceanic scales, less than 20 km in size, are thought to drive a significant downward heat transport from the surface to the ocean interior, which increases oceanic heat uptake. Here we use a combination of satellite and in situ observations in the Antarctic Circumpolar Current to diagnose oceanic vertical heat transport. The results explicitly demonstrate how deep-reaching submesoscale fronts, with a size smaller than 20 km, are generated by mesoscale eddies of size 50-300 km. In contrast to the classical paradigm, these submesoscale fronts are shown to drive an anomalous upward heat transport from the ocean interior back to the surface that is larger than other contributions to vertical heat transport and of comparable magnitude to air-sea fluxes. This effect can remarkably alter the oceanic heat uptake and will be strongest in eddy-rich regions, such as the Antarctic Circumpolar Current, the Kuroshio Extension and the Gulf Stream, all of which are key players in the climate system.