Eddy‐Driven Transport of Particulate Organic Carbon‐Rich Coastal Water Off the West Antarctic Peninsula. Issue 3 (22nd March 2021)

• Record Type: Journal Article
• Authors: Castelao, Renato M.; Dinniman, Michael S.; Amos, Caitlin M.; Klinck, John M.; Medeiros, Patricia M.
• Is Part Of: Journal of geophysical research. Volume 126:Issue 3(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-22
• Subjects: cross‐shelf transport -- mesoscale eddies -- particulate organic carbon -- West Antarctic Peninsula; Oceanography -- Periodicals; 551.4605
• DOI: 10.1029/2020JC016791
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: The Southern Ocean is characterized by high eddy activity and high particulate organic carbon (POC) content during summer, especially near Antarctica. Because it encircles the globe, it provides a pathway for inter‐basin exchange. Here, we use satellite observations and a high‐resolution ocean model to quantify offshore transport of coastal water rich in POC off the West Antarctic Peninsula. We show that nonlinear cyclonic eddies generated near the coast often trap coastal water rich in POC during formation before propagating offshore. As a result, cyclones found offshore that were generated near the coast have on average higher POC content in their interior than cyclones generated locally offshore. This results in a POC enrichment of 5.7 ± 3.0 Gg C year −1 in offshore waters off the Peninsula. Actual POC enrichment is likely substantially larger, since about half of the volume transport of coastal water is driven by small eddies that are missed by observations. Plain Language Summary: Coastal waters off Antarctica during summer are generally highly productive, being characterized by high concentrations of particulate organic carbon (POC). Mechanisms driving offshore transport of coastal water are important because they contribute to spreading that organic carbon over large areas of the Southern Ocean. Here, we combine satellite observations and model results to show that when cyclonic eddies are generated near the coast, they often trap coastal water rich in POC in their interior. As those eddies propagate offshore, they carry that signature with them, resulting in POC enrichment in offshore areas. Model results indicate that small eddies, which are generally missed by satellite altimetry, can account for half of the eddy‐driven volume transport of coastal water. Key Points: Cyclonic eddies generated near the coast off the West Antarctic Peninsula often propagate offshore Those eddies can trap coastal water rich in particulate organic carbon (POC) in their interior, resulting in POC enrichment in offshore waters off the Peninsula Model results suggest that half of the eddy‐driven volume transport of coastal water is due to small eddies that are missed by altimetry