Do submesoscale frontal processes ventilate the oxygen minimum zone off Peru?. Issue 15 (8th August 2016)

• Record Type: Journal Article
• Authors: Thomsen, S.; Kanzow, T.; Colas, F.; Echevin, V.; Krahmann, G.; Engel, A.
• Is Part Of: Geophysical research letters. Volume 43:Issue 15(2016)
• Page Start: 8133
• Page End: 8142
• Publication Date: 2016-08-08
• Subjects: oxygen minimum zone -- submesoscale -- subduction -- Peru -- upwelling -- ventilation; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL070548
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The Peruvian upwelling system encompasses the most intense and shallowest oxygen minimum zone (OMZ) in the ocean. This system shows pronounced submesoscale activity like filaments and fronts. We carried out glider‐based observations off Peru during austral summer 2013 to investigate whether submesoscale frontal processes ventilate the Peruvian OMZ. We present observational evidence for the subduction of highly oxygenated surface water in a submesoscale cold filament. The subduction event ventilates the oxycline but does not reach OMZ core waters. In a regional submesoscale‐permitting model we study the pathways of newly upwelled water. About 50% of upwelled virtual floats are subducted below the mixed layer within 5 days emphasizing a hitherto unrecognized importance of subduction for the ventilation of the Peruvian oxycline. Key Points: Observed subduction of oxygenated surface water in a submesoscale filament off Peru Submesoscale‐permitting model simulations confirm that subduction occurs in filaments off Peru Lagrangian float diagnostics suggest that 50% of the newly upwelled water is subducted