FN Archimer Export Format
PT J
TI Interior Water-Mass Variability in the Southern Hemisphere Oceans during the Last Decade
BT 
AF PORTELA, Esther
   KOLODZIEJCZYK, Nicolas
   MAES, Christophe
   THIERRY, Virginie
AS 1:2;2:3;3:4;4:1;
FF 1:;2:;3:;4:PDG-ODE-LOPS-OH;
C1 Univ Brest, IFREMER, CNRS, Lab Oceanog Phys & Spatiale,IRD, Plouzane, France.
   Univ Brest, IFREMER, CNRS, Lab Oceanog Phys & Spatiale,IRD, Plouzane, France.
   Univ Brest, IFREMER, CNRS, Lab Oceanog Phys & Spatiale,IRD, Plouzane, France.
   Univ Brest, IFREMER, CNRS, Lab Oceanog Phys & Spatiale,IRD, Plouzane, France.
C2 IFREMER, FRANCE
   CNRS, FRANCE
   UBO, FRANCE
   IRD, FRANCE
SI BREST
SE PDG-ODE-LOPS-OH
UM LOPS
IN WOS Ifremer UMR
   WOS Cotutelle UMR
   copubli-france
   copubli-p187
   copubli-univ-france
IF 3.373
TC 32
UR https://archimer.ifremer.fr/doc/00609/72065/70771.pdf
   https://archimer.ifremer.fr/doc/00609/72065/70772.pdf
LA English
DT Article
DE ;Southern Hemisphere;Water masses;storage;Isopycnal mixing;Water budget;balance;In situ oceanic observations;Decadal variability
AB Using an Argo dataset and the ECCOv4 reanalysis, a volume budget was performed to address the main mechanisms driving the volume change of the interior water masses in the Southern Hemisphere oceans between 2006 and 2015. The subduction rates and the isopycnal and diapycnal water-mass transformation were estimated in a density-spiciness (sigma-tau) framework. Spiciness, defined as thermohaline variations along isopycnals, was added to the potential density coordinates to discriminate between water masses spreading on isopycnal layers. The main positive volume trends were found to be associated with the Subantarctic Mode Waters (SAMW) in the South Pacific and South Indian Ocean basins, revealing a lightening of the upper waters in the Southern Hemisphere. The SAMW exhibits a two-layer density structure in which subduction and diapycnal transformation from the lower to the upper layers accounted for most of the upper-layer volume gain and lower-layer volume loss, respectively. The Antarctic Intermediate Waters, defined here between the 27.2 and 27.5 kg m(-3) isopycnals, showed the strongest negative volume trends. This volume loss can be explained by their negative isopyncal transformation southward of the Antarctic Circumpolar Current into the fresher and colder Antarctic Winter Waters (AAWW) and northward into spicier tropical/subtropical Intermediate Waters. The AAWW is destroyed by obduction back into the mixed layer so that its net volume change remains nearly zero. The proposed mechanisms to explain the transformation within the Intermediate Waters are discussed in the context of Southern Ocean dynamics. The sigma-tau decomposition provided new insight on the spatial and temporal water-mass variability and driving mechanisms over the last decade. 
PY 2020
PD FEB
SO Journal Of Physical Oceanography
SN 0022-3670
PU Amer Meteorological Soc
VL 50
IS 2
UT 000510891200001
BP 361
EP 381
DI 10.1175/JPO-D-19-0128.1
ID 72065
ER

EF