Anatomy of subinertial waves along the Patagonian shelf break in a 1/12° global operational model

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Poli, Léa, Artana, Camila, Provost, Christine, Sirven, Jérôme, Sennéchael, Nathalie, Cuypers, Yannis, Lellouche, Jean-Michel
• Other Authors: Austral, Boréal et Carbone (ABC), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Mercator Océan, Société Civile CNRS Ifremer IRD Météo-France SHOM, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Variabilité de l'Océan et de la Glace de mer (VOG), Processus et interactions de fine échelle océanique (PROTEO)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: topographic waves; shelf break; Malvinas Current; jets; upwelling; global operational model; Current-meter data; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Drake Passage; Malvinas Escarpment
• Online Access: https://hal.science/hal-03015284; https://hal.science/hal-03015284/document; https://hal.science/hal-03015284/file/Poli2020JC016549.pdf; https://doi.org/10.1029/2020jc016549

International audience The Patagonian slope hosts a variety of waves. We used a state of the art ocean reanalysis to examine waves at the shelf break and in the core of the Malvinas Current (MC) at periods larger than 10 days. Statistics over 25 years indicated three types of signals: in phase signals at specific locations of the shelf break to the south of 47°S, fast propagating signals all along the shelf break (phase speed from 140 cm/s to 300 cm/s) at periods between 5 and 110 days, and slower signals in the core of the MC (phase speeds from 10 cm/s to 30 cm/s) at 20‐day, 60‐day and 100‐day periods.The large zonal wind stress variations south of 47°S forced in‐phase along‐slope velocity variations and triggered fast propagating waves at distinct sites corresponding to abrupt changes in the shelf break orientation. The shelf break waves modulated the intensity of the inshore jet, which varied from 0 to 30 cm/s at 100 m depth, and had spatial and temporal structures and scales consistent with those of observed upwelling events. Slow propagating waves in the core of the MC had along‐slope wavelengths between 450 and 1200 km and were not forced by the local winds. They were tracked back to the Drake Passage and the Malvinas Escarpment.