TY - JOUR
T1 - Comparison study of subtropical mode waters in the world ocean
AU - Tsubouchi, Takamasa
AU - Suga, Toshio
AU - Hanawa, Kimio
N1 - Funding Information:
We acknowledge fruitful discussions with members of Physical Oceanography Group at Tohoku University. This study was performed as a part of the twenty-first Century Center-Of-Excellence (COE) Program "Advanced Science and Technology Center for Dynamic Earth (E-ASTEC)" at Tohoku University. Comments from two reviewers improved the quality of paper. Dr Jeremy Grist did English editing. The second author (TS) was supported by the Grant-in-Aid from the Japan Society for the Promotion of Science (15H02129 and 25287118).
Publisher Copyright:
© 2016 Tsubouchi, Suga and Hanawa.
PY - 2016
Y1 - 2016
N2 - Subtropical Mode Water (STMW) is a distinctive feature of the upper ocean in the western part of subtropical gyres in the world ocean. This paper proposes a common criterion of STMW to quantify and compare spatial structures of STMWs in different basins. STMW can be defined as a thermostad (a layer weakly stratified in temperature) by applying a criterion of averaged core layer temperature (CLT) ± 1°C with its layer thickness > 100 m. Two features are highlighted when comparing the STMWs in different basins. Firstly, the North Atlantic hosts the thickest STMW in the world ocean. Secondly, the South Atlantic STMW has an unique vertical structure of density compensating temperature and salinity stratification. By comparing the thickness of STMW against the strength of winter cooling and the volume transport of associated western boundary current (WBC) in different basins, it is shown that thicker STMW tends to be accompanied with stronger WBC. From a view point of vorticity dynamics, we suggest that the North Atlantic may have the most efficient condition to host the thickest STMW and the strongest recirculation gyre in the world ocean.
AB - Subtropical Mode Water (STMW) is a distinctive feature of the upper ocean in the western part of subtropical gyres in the world ocean. This paper proposes a common criterion of STMW to quantify and compare spatial structures of STMWs in different basins. STMW can be defined as a thermostad (a layer weakly stratified in temperature) by applying a criterion of averaged core layer temperature (CLT) ± 1°C with its layer thickness > 100 m. Two features are highlighted when comparing the STMWs in different basins. Firstly, the North Atlantic hosts the thickest STMW in the world ocean. Secondly, the South Atlantic STMW has an unique vertical structure of density compensating temperature and salinity stratification. By comparing the thickness of STMW against the strength of winter cooling and the volume transport of associated western boundary current (WBC) in different basins, it is shown that thicker STMW tends to be accompanied with stronger WBC. From a view point of vorticity dynamics, we suggest that the North Atlantic may have the most efficient condition to host the thickest STMW and the strongest recirculation gyre in the world ocean.
KW - Ocean stratification
KW - Potential vorticity dynamics
KW - Subtropical gyre
KW - Subtropical mode water
KW - Western boundary current
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U2 - 10.3389/fmars.2016.00270
DO - 10.3389/fmars.2016.00270
M3 - Article
AN - SCOPUS:85008626097
SN - 2296-7745
VL - 3
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
IS - DEC
M1 - 270
ER -