FN Archimer Export Format PT J TI Mean structure of the North Atlantic subtropical permanent pycnocline from in-situ observations BT AF FEUCHER, Charlene MAZE, Guillaume MERCIER, Herle AS 1:1;2:1;3:2; FF 1:PDG-ODE-LOPS-OH;2:PDG-ODE-LOPS-OH;3:; C1 IFREMER, Lab Oceanog Phys & Spatiale, CS 10070, Plouzane, France. CNRS, Lab Oceanog Phys & Spatiale, Plouzane, France. C2 IFREMER, FRANCE CNRS, FRANCE SI BREST SE PDG-ODE-LOPS-OH UM LOPS IN WOS Ifremer jusqu'en 2018 copubli-france IF 2.233 TC 13 UR https://archimer.ifremer.fr/doc/00326/43710/44712.pdf LA English DT Article AB A new Objective Algorithm for the Characterization of the permanent Pycnocline (OACP) in subtropical gyres is proposed. OAC-P is based on a pragmatic analysis of vertical density gradient features to identify the permanent pycnocline: OAC-P identifies the permanent pycnocline as the stratified layer found below surface mode waters. OAC-P provides the permanent pycnocline depth, unequivocally associated with a local maximum in the stratification, and top and bottom thicknesses, associated with upward and downward decreases in stratification. OAC-P uses half Gaussian curves as asymmetric non-linear analytical models of the stratification peak. It is the first time that an algorithm is proposed to characterize objectively the permanent pycnocline for a region where handling the stronger stratification peak of the seasonal pycnocline is complex. A guideline for how-to implement OAC-P is given, with application to the North Atlantic Ocean Argo data as example. OAC-P provides a detailed description of the mean structure of the North Atlantic subtropical permanent pycnocline. OAC-P detects a permanent pycnocline throughout the subtropical gyre north of the North Equatorial Current. The large scale description of the permanent pycnocline depth structure as a classic bowl shape is captured however with much more details. New regional information is provided. In particular: (i) there is only one region - the southern recirculation gyre of the Gulf Stream Extension - where the permanent pycnocline is along an isopycnal surface and (ii) vertical asymmetries clearly discriminate one region from another. PY 2016 PD JUL SO Journal Of Atmospheric And Oceanic Technology SN 0739-0572 PU Amer Meteorological Soc VL 33 IS 6 UT 000377942700015 BP 1285 EP 1308 DI 10.1175/JTECH-D-15-0192.1 ID 43710 ER EF