@article{fdi:010085076,
  title = {{O}verturning instabilities across a warm core ring from glider observations},
  author = {{P}erez, {J}. {G}. {C}. and {P}allas-{S}anz, {E}. and {T}enreiro, {M}. and {M}eunier, {T}. and {J}ouanno, {J}ulien and {R}uiz-{A}ngulo, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his work presents new evidence for conducive conditions for the existence of overturning instabilities in the mixed layer across a mesoscale anticyclonic {L}oop {C}urrent {E}ddy ({LCE}) and surrounding cyclonic eddies in the {G}ulf of {M}exico ({G}o{M}). {T}he {LCE} was intensively sampled using four gliders during 12 months. {T}he {LCE} is characterized by a strong anomaly of fresh and warm water in the center and strong strain at the periphery. {M}ixed layers prone to overturning instabilities are diagnosed from the gradients of buoyancy. {I}n the {G}o{M}, the reduction of potential vorticity ({PV}) in the mixed layer is driven by surface cooling by year-round persistent negative turbulent heat fluxes, eventually reaching -700 {W} m(-2) during extreme winter wind events. {L}ateral buoyancy gradients associated with submesoscale filaments and fronts at the periphery of the {LCE} enhance the frictional torque supplied by the wind stress when aligned with the geostrophic jet current. {N}egative {PV} in the mixed layer occurs simultaneously with negative turbulent heat fluxes and events of {E}kman buoyancy fluxes that reduce the stratification. {T}hese regions are susceptible to mixed-layer gravitational-symmetric instability preferentially in winter. {E}xtreme {E}kman equivalent heat flux (<=-10,000 {W} m(-2)) associated with wind stress of 1.2 {N} m(-2) coincides with the development of inertial-symmetric instability across anticyclonic vorticity. {T}hese observations might have several implications for the restratification processes, kinetic energy budget, and biogeochemical cycles inside {LCE}s and can contribute to the formation of low-{PV} waters that could feed mode water formation inside the {G}o{M}.},
  keywords = {overturning instabilities ; {E}kman buoyancy flux ; mesoscale {L}oop {C}urrent ; {E}ddies gliders ; {G}ulf of {M}exico ; submesoscale ; {ATLANTIQUE} ; {GOLFE} {DU} {MEXIQUE}},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch : {O}ceans},
  volume = {127},
  numero = {4},
  pages = {e2021{JC}017527 [25 ]},
  ISSN = {2169-9275},
  year = {2022},
  DOI = {10.1029/2021jc017527},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085076},
}