FN Archimer Export Format
PT J
TI Contrasted mixing efficiency in energetic versus quiescent regions: insights from microstructure measurements in the Western Mediterranean Sea
BT 
AF Vladoiu, Anda
   Bouruet-Aubertot, Pascale
   Cuypers, Yannis
   Ferron, Bruno
   Schroeder, Katrin
   Borghini, Mireno
   Leizour, Stephane
AS 1:1;2:1;3:1;4:5;5:3;6:4;7:2;
FF 1:;2:;3:;4:;5:;6:;7:PDG-ODE-LOPS-TOIS;
C1 Sorbonne Université UPMC Paris VI - LOCEAN, France
   University of Brest, CNRS, IFREMER, IRD, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France
   CNR-ISMAR, Venice, Italy
   CNR-ISMAR, Lerici (SP), Italy
   University of Brest, CNRS, IFREMER, IRD, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France
C2 UNIV PARIS 06, FRANCE
   IFREMER, FRANCE
   CNR ISMAR, ITALY
   CNR ISMAR, ITALY
   CNRS, FRANCE
SI BREST
SE PDG-ODE-LOPS-TOIS
UM LOPS
IN WOS Ifremer UMR
   WOS Cotutelle UMR
   copubli-france
   copubli-europe
   copubli-univ-france
IF 4.416
TC 3
UR https://archimer.ifremer.fr/doc/00694/80580/83798.pdf
LA English
DT Article
DE ;Microstructure measurements;Mixing efficiency;Turbulent diapycnal mixing;Mediterranean Sea
AB Microstructure and CTD/LADCP measurements from the Western Mediterranean basin east of revealed two types of dynamical regions (Ferron et al., 2017, Geophysical Research Letters, 44:7845-7854, Ferron et al., 2017), contrasted in terms of current magnitude, vertical shear, stratification and turbulent kinetic energy dissipation rate: energetic regions (Corsica Channel, Egadi Valley and Sicily Channel) and quiescent regions (Ligurian Sea, around Sardinia, and Tyrrhenian Sea). On average, the current speed and the buoyancy frequency in the energetic regions were twice as large as in the quiescent regions, and the vertical shear was five times as large. Turbulence properties inferred from the microstructure measurements were also contrasted, dissipation rates in the energetic regions being two orders of magnitude larger than in the quiescent regions. The present study investigates the variability of the dissipation flux coefficient, a measure of the mixing efficiency, in a rich assortment of dynamical regimes. This dataset covers the full range of turbulence intensities observed in previous studies based on field measurements, direct numerical simulations, and laboratory experiments alike. The dependency of the dissipation flux coefficient as a function of turbulence intensity for the quiescent and energetic regions frames the previously observed lower and upper bounds, respectively. A contrasting behaviour was revealed between the two types of regions. In the quiescent regions, the dissipation flux coefficient linearly decreases on average by one order of magnitude with turbulence intensity increasing by four orders of magnitude. On the other hand, in the energetic regions the dissipation flux coefficient exhibits a nearly constant value over 4 decades of turbulence intensity, before decreasing for very strong turbulence intensities. In contrast with other studies, this dataset shows no relationship between the Richardson number and the dissipation flux coefficient. This may be due to inadequate vertical sampling resolution of the currents, or to the high diversity of sampled turbulent regimes, contrary to previous studies focused on a single type of dynamical region or framework (such as the thermocline or shear instabilities). 
PY 2021
PD JUN
SO Progress In Oceanography
SN 0079-6611
PU Elsevier BV
VL 195
UT 000660310900003
DI 10.1016/j.pocean.2021.102594
ID 80580
ER

EF