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dc.contributor.authordu Plessis, Marcel  Concept link
dc.contributor.authorSwart, Sebastiaan  Concept link
dc.contributor.authorAnsorge, Isabelle  Concept link
dc.contributor.authorMahadevan, Amala  Concept link
dc.contributor.authorThompson, Andrew F.  Concept link
dc.date.accessioned2019-06-07T15:14:24Z
dc.date.available2020-04-11T08:03:26Z
dc.date.issued2019-04-11
dc.identifier.citationDu Plessis, M., Swart, S., Ansorge, I. J., Mahadevan, A., & Thompson, A. F. (2019). Southern Ocean seasonal restratification delayed by submesoscale wind-front interactions. Journal of Physical Oceanography, 49(4), 1035-1053en_US
dc.identifier.urihttps://hdl.handle.net/1912/24212
dc.descriptionAuthor Posting. © American Meteorological Society, 2019. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 49(4), (2019): 1035-1053, doi:10.1175/JPO-D-18-0136.1.en_US
dc.description.abstractOcean stratification and the vertical extent of the mixed layer influence the rate at which the ocean and atmosphere exchange properties. This process has direct impacts for anthropogenic heat and carbon uptake in the Southern Ocean. Submesoscale instabilities that evolve over space (1–10 km) and time (from hours to days) scales directly influence mixed layer variability and are ubiquitous in the Southern Ocean. Mixed layer eddies contribute to mixed layer restratification, while down-front winds, enhanced by strong synoptic storms, can erode stratification by a cross-frontal Ekman buoyancy flux. This study investigates the role of these submesoscale processes on the subseasonal and interannual variability of the mixed layer stratification using four years of high-resolution glider data in the Southern Ocean. An increase of stratification from winter to summer occurs due to a seasonal warming of the mixed layer. However, we observe transient decreases in stratification lasting from days to weeks, which can arrest the seasonal restratification by up to two months after surface heat flux becomes positive. This leads to interannual differences in the timing of seasonal restratification by up to 36 days. Parameterizing the Ekman buoyancy flux in a one-dimensional mixed layer model reduces the magnitude of stratification compared to when the model is run using heat and freshwater fluxes alone. Importantly, the reduced stratification occurs during the spring restratification period, thereby holding important implications for mixed layer dynamics in climate models as well as physical–biological coupling in the Southern Ocean.en_US
dc.description.sponsorshipMdP acknowledges numerous research visits to the Department of Marine Science, University of Gothenburg, and a visit to Woods Hole Oceanographic Institution, which greatly enhanced this work. We thank SANAP and the captain and crew of the S.A. Agulhas II for their assistance in the deployment and retrieval of the gliders. We acknowledge the work of SAMERC-STS for housing, managing, and piloting the gliders. SS was supported by NRF-SANAP Grant SNA14071475720 and a Wallenberg Academy Fellowship (WAF 2015.0186). Lastly, SS thanks the numerous technical assistance, advice, and IOP hosting provided by Geoff Shilling and Craig Lee of the Applied Physics Laboratory, University of Washington.en_US
dc.publisherAmerican Meteorological Societyen_US
dc.relation.urihttps://doi.org/10.1175/JPO-D-18-0136.1
dc.subjectAtmosphere-ocean interactionen_US
dc.subjectFrontsen_US
dc.subjectOceanic mixed layeren_US
dc.subjectIn situ oceanic observationsen_US
dc.subjectInterannual variabilityen_US
dc.subjectSeasonal cycleen_US
dc.titleSouthern Ocean seasonal restratification delayed by submesoscale wind-front interactionsen_US
dc.typeArticleen_US
dc.description.embargo2020-04-11en_US
dc.identifier.doi10.1175/JPO-D-18-0136.1


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