Skip to Main content Skip to Navigation
Journal articles

Wind-Forced Submesoscale Symmetric Instability around Deep Convection in the Northwestern Mediterranean Sea

Abstract : During the winter from 2009 to 2013, the mixed layer reached the seafloor at about 2500min the northwestern Mediterranean Sea. Intense fronts around the deep convection area were repeatedly sampled by autonomous gliders. Subduction down to 200–300 m, sometimes deeper, below the mixed layer was regularly observed testifying of important frontal vertical movements. Potential Vorticity dynamics was diagnosed using glider observations and a high resolution realistic model at 1-km resolution. During down-front wind events in winter, remarkable layers of negative PV were observed in the upper 100m on the dense side of fronts surrounding the deep convection area and successfully reproduced by the numerical model. Under such conditions, symmetric instability can grow and overturn water along isopycnals within typically 1–5 km cross-frontal slanted cells. Two important hotpspots for the destruction of PV along the topographically-steered Northern Current undergoing frequent down-front winds have been identified in the western part of Gulf of Lion and Ligurian Sea. Fronts were there symmetrically unstable for up to 30 days per winter in the model, whereas localized instability events were found in the open sea, mostly influenced by mesoscale variability. The associated vertical circulations also had an important signature on oxygen and fluorescence, highlighting their under important role for the ventilation of intermediate layers, phytoplankton growth and carbon export.
Document type :
Journal articles
Complete list of metadata

https://hal-amu.archives-ouvertes.fr/hal-03199242
Contributor : Anthony Bosse Connect in order to contact the contributor
Submitted on : Thursday, April 15, 2021 - 3:48:04 PM
Last modification on : Wednesday, November 17, 2021 - 12:33:29 PM
Long-term archiving on: : Friday, July 16, 2021 - 6:56:26 PM

File

fluids-06-00123.pdf
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

Anthony Bosse, Pierre Testor, Pierre Damien, Claude Estournel, Patrick Marsaleix, et al.. Wind-Forced Submesoscale Symmetric Instability around Deep Convection in the Northwestern Mediterranean Sea. Fluids, MDPI, 2021, 6 (3), pp.123. ⟨10.3390/fluids6030123⟩. ⟨hal-03199242⟩

Share

Metrics

Record views

263

Files downloads

283