The Contribution of Submesoscale over Mesoscale Eddy Iron Transport in the Open Southern Ocean

• Published in: Journal of Advances in Modeling Earth Systems
• Main Authors: Uchida, Takaya, Balwada, Dhruv, Abernathey, Ryan P., Mckinley, Galen, Smith, K. Shafer, Lévy, Marina
• Other Authors: Department of Earth and Environmental Sciences New York, Columbia University New York, Lamont-Doherty Earth Observatory (LDEO), Center for Atmosphere Ocean Science NYU (CAOS), Courant Institute of Mathematical Sciences New York (CIMS), New York University New York (NYU), NYU System (NYU)-NYU System (NYU)-New York University New York (NYU), NYU System (NYU)-NYU System (NYU), Processus et interactions de fine échelle océanique (PROTEO), 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), NASA. Grant Number: NNX16AJ35GNSF. Grant Numbers: OCE-1553593, OCE-1740648
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; Antarc*; Antarctic; Southern Ocean
• Online Access: https://hal.science/hal-02422867; https://hal.science/hal-02422867/document; https://hal.science/hal-02422867/file/2019MS001805.pdf; https://doi.org/10.1029/2019MS001805

International audience Biological productivity in the Southern Ocean is limited by iron availability. Previous studies of iron supply have focused on mixed‐layer entrainment and diapycnal fluxes. However, the Southern Ocean is a region highly energetic mesoscale and submesoscale turbulence. Here we investigate the role of eddies in supplying iron to the euphotic zone, using a flat‐bottom zonally re‐entrant model, configured to represent the Antarctic Circumpolar Current region, that is coupled to a biogeochemical model with a realistic seasonal cycle. Eddies are admitted or suppressed by changing the model's horizontal resolution. We utilize cross spectral analysis and the generalized Omega equation to temporally and spatially decompose the vertical transport attributable to mesoscale and submesoscale motions. Our results suggest that the mesoscale vertical fluxes provide a first‐order pathway for transporting iron across the mixing‐layer base, where diapycnal mixing is weak, and must be included in modeling the open‐Southern Ocean iron budget.