Evidence of coupling in ocean-atmosphere dynamics over the North Atlantic

• Published in: Geophysical Research Letters
• Main Authors: Vannitsem, Stéphane, Ghil, Michael
• Other Authors: Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: ocean-atmosphere coupling; phase space reconstruction; multichannel singular spectrum analysis; analogs; predictability; ocean-atmosphere dynamics; [SDU]Sciences of the Universe [physics]; North Atlantic
• Online Access: https://insu.hal.science/insu-03727080; https://insu.hal.science/insu-03727080/document; https://insu.hal.science/insu-03727080/file/Geophysical%20Research%20Letters%20-%202017%20-%20Vannitsem%20-%20Evidence%20of%20coupling%20in%20ocean%25u2010atmosphere%20dynamics%20over%20the%20North%20Atlantic.pdf; https://doi.org/10.1002/2016GL072229

International audience Coupling between the ocean and the atmosphere is investigated in reanalysis data sets. Projecting the data sets onto a dynamically defined subspace allows one to isolate the dominant modes of variability of the coupled system. This coupled projection is then analyzed using multichannel singular spectrum analysis. The results suggest that a dominant low-frequency signal with a 25-30 year period already mentioned in the literature is a common mode of variability of the atmosphere and the ocean. A new score for evaluating the internal nature of the common variability is then introduced, and it confirms the presence of coupled dynamics in the ocean-atmosphere system that impacts the atmosphere at large scale. The physical nature of this coupled dynamics is then discussed.