Agulhas Ring Heat Content and Transport in the South Atlantic Estimated by Combining Satellite Altimetry and Argo Profiling Floats Data

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Laxenaire, R., Speich, S., Stegner, A.
• Other Authors: Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-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 2020
• Subjects: subduction of most of the Agulhas rings in the South Atlantic; comparison of numerous methods of eddy reconstruction; new estimate of ∼0.02 PW heat flux achieved by the Agulhas ring in the South Atlantic Ocean; [SDU]Sciences of the Universe [physics]; South Atlantic Ocean
• Online Access: https://insu.hal.science/insu-03726972; https://insu.hal.science/insu-03726972/document; https://insu.hal.science/insu-03726972/file/JGR%20Oceans%20-%202020%20-%20Laxenaire%20-%20Agulhas%20Ring%20Heat%20Content%20and%20Transport%20in%20the%20South%20Atlantic%20Estimated%20by%20Combining.pdf; https://doi.org/10.1029/2019JC015511

International audience The Agulhas leakage of Indian Ocean waters into the Atlantic has been shown to be a key link in global ocean circulation and climate; an increased understanding of this process is therefore of more than just of local interest. While knowledge of the Agulhas leakage has increased over the past 30 years, the precise mechanisms at play and water properties transferred are still not sufficiently documented. This study covers the Agulhas rings heat content and transport, which contribute to the meridional overturning circulation of the global ocean during their route across the South Atlantic Ocean. By applying TOEddies, an eddy detection and tracking algorithm that takes into account eddy merging and splitting, to satellite altimetry maps combined with a colocation of the detected eddies with Argo floats vertical profiles, we are able to document the important heat anomaly characterizing Agulhas rings and their evolution across the Cape Basin and the South Atlantic Ocean. Notwithstanding that in situ data coverage is still limited at the ocean mesoscale, we have estimated an averaged Agulhas rings subsurface heat transport of 2.5 × 10 -2 PW and 1.5 × 10 -2 PW across the eastern and western South Atlantic Ocean, respectively.