FN Archimer Export Format
PT J
TI The ocean mixed layer under Southern Ocean sea-ice: Seasonal cycle and forcing
BT 
AF PELLICHERO, Violaine
   SALLEE, Jean-Baptiste
   SCHMIDTKO, Sunke
   ROQUET, Fabien
   CHARRASSIN, Jean-Benoit
AS 1:1;2:1;3:2;4:3;5:1;
FF 1:;2:;3:;4:;5:;
C1 UPMC Univ Paris 06, Sorbonne Univ, UMR 7159, LOCEAN,IPSL, F-75005 Paris, France.
   GEOMAR Helmholtz Ctr Ocean Res Kiel, Kiel, Germany.
   Stockholm Univ, Dept Meteorol, Stockholm, Sweden.
C2 UNIV PARIS 06, FRANCE
   GEOMAR, GERMANY
   UNIV STOCKHOLM, SWEDEN
IF 2.711
TC 87
UR https://archimer.ifremer.fr/doc/00383/49400/49901.pdf
LA English
DT Article
CR OISO - OCÉAN INDIEN SERVICE D'OBSERVATION
DE ;Southern Ocean;mixed layer;sea-ice;elephant seals;salt budget;heat budget
AB The oceanic mixed layer is the gateway for the exchanges between the atmosphere and the ocean; in this layer, all hydrographic ocean properties are set for months to millennia. A vast area of the Southern Ocean is seasonally capped by sea-ice, which alters the characteristics of the ocean mixed layer. The interaction between the ocean mixed layer and sea-ice plays a key role for water mass transformation, the carbon cycle, sea-ice dynamics, and ultimately for the climate as a whole. However, the structure and characteristics of the under-ice mixed layer are poorly understood due to the sparseness of in situ observations and measurements. In this study, we combine distinct sources of observations to overcome this lack in our understanding of the polar regions. Working with elephant seal-derived, ship-based, and Argo float observations, we describe the seasonal cycle of the ocean mixed-layer characteristics and stability of the ocean mixed layer over the Southern Ocean and specifically under sea-ice. Mixed-layer heat and freshwater budgets are used to investigate the main forcing mechanisms of the mixed-layer seasonal cycle. The seasonal variability of sea surface salinity and temperature are primarily driven by surface processes, dominated by sea-ice freshwater flux for the salt budget and by air-sea flux for the heat budget. Ekman advection, vertical diffusivity, and vertical entrainment play only secondary roles. Our results suggest that changes in regional sea-ice distribution and annual duration, as currently observed, widely affect the buoyancy budget of the underlying mixed layer, and impact large-scale water mass formation and transformation with far reaching consequences for ocean ventilation.
PY 2017
PD FEB
SO Journal Of Geophysical Research-oceans
SN 2169-9275
PU Amer Geophysical Union
VL 122
IS 2
UT 000398063100048
BP 1608
EP 1633
DI 10.1002/2016JC011970
ID 49400
ER

EF