FN Archimer Export Format PT J TI Mixed and mixing layer depths in the ocean surface boundary layer under conditions of diurnal stratification BT AF SUTHERLAND, G. REVERDIN, Gilles MARIE, Louis WARD, Ben AS 1:1;2:2;3:3,4;4:1; FF 1:;2:;3:PDG-ODE-LPO;4:; C1 Natl Univ Ireland, Sch Phys, Galway, Ireland Univ Paris 06, Univ Sorbonne,Paris VI Denis Diderot Univ, Denis Diderot Univ,CNRS,IRD,MNHN, LOCEAN,Inst Pierre Simon Lapl Expt & Approches Nu, F-75252 Paris 05, France UBO, IRD, IFREMER, Lab Phys Oceans,UMR 6523,CNRS, Plouzane, France Ifremer, France C2 UNIV NATL IRELAND, IRELAND UNIV PARIS 06, FRANCE UBO, FRANCE IFREMER, FRANCE SI BREST SE PDG-ODE-LPO IN WOS Ifremer jusqu'en 2018 copubli-france copubli-europe copubli-univ-france IF 4.196 TC 33 UR https://archimer.ifremer.fr/doc/00240/35101/33594.pdf LA English DT Article CR STRASSE BO Thalassa DE ;ocean surface boundary layer;mixed and mixing layer depths;buoyancy AB A comparison between mixed (MLD) and mixing (XLD) layer depths is presented from the SubTRopical Atlantic Surface Salinity Experiment (STRASSE) cruise in the subtropical Atlantic. This study consists of 400 microstructure profiles during fairly calm and moderate conditions (2 < U10 < 10 m s−1) and strong solar heating O(1000 W m−2). The XLD is determined from a decrease in the turbulent dissipation rate to an assumed background level. Two different thresholds for the background dissipation level are tested, 10−8 and 10−9 m2 s−3, and these are compared with the MLD as calculated using a density threshold. The larger background threshold agrees with the MLD during restratification but only extends to half the MLD during nighttime convection, while the lesser threshold agrees well during convection but is deeper by a factor of 2 during restratification. Observations suggest the use of a larger density threshold to determine the MLD in a buoyancy driven regime. PY 2014 PD DEC SO Geophysical Research Letters SN 0094-8276 PU Amer Geophysical Union VL 41 IS 23 UT 000348462000042 BP 8469 EP 8476 DI 10.1002/2014GL061939 ID 35101 ER EF