TY - JOUR
T1 - Eddy fluxes and jet-scale overturning circulations in the indo-western pacific southern ocean
AU - Li, Qian
AU - Lee, Sukyoung
AU - Griesel, Alexa
N1 - Funding Information:
We thank Mat Maltrud for providing the tripole POP setup and grid and initial conditions. Many thanks to Elena Yulaeva for setting up the runs and providing data and to Julie McClean for suggesting this POP run and for initiating the collaboration between SL-QL and AG. SL and QL also appreciate comments by Cory Baggett and Steven Feldstein on the manuscript. QL and SL were supported by the National Science Foundation under Grant ATM-1139970. SL was also supported by Seoul National University, the Republic of Korea, through the Next Generation Distinguished Scholars Award. AG was supported by the Collaborative Research Centre TRR 181 on Energy Transfer inAtmosphere andOcean funded by the German Research Foundation. An allocation of advanced computing resourcesOCE-0960914 provided by the National Science Foundation was instrumental in performing this research. The computations were performed on Kraken at the National Institute for Computational Sciences (http://www.nics.tennessee.edu/).
Publisher Copyright:
© 2016 American Meteorological Society.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016
Y1 - 2016
N2 - The relationship between Antarctic Circumpolar Current jets and eddy fluxes in the Indo-western Pacific Southern Ocean (90°-145°E) is investigated using an eddy-resolving model. In this region, transient eddy momentum flux convergence occurs at the latitude of the primary jet core, whereas eddy buoyancy flux is located over a broader region that encompasses the jet and the interjet minimum. In a small sector (120°-144°E) where jets are especially zonal, a spatial and temporal decomposition of the eddy fluxes further reveals that fast eddies act to accelerate the jet with the maximum eddy momentum flux convergence at the jet center, while slow eddies tend to decelerate the zonal current at the interjet minimum. Transformed Eulerian mean (TEM) diagnostics reveals that the eddy momentum contribution accelerates the jets at all model depths, whereas the buoyancy flux contribution decelerates the jets at depths below ~600 m. In ocean sectors where the jets are relatively well defined, there exist jet-scale overturning circulations with sinking motion on the equatorward flank and a rising motion on the poleward flank of the jets. These jet-scale TEM overturning circulations, which are also discernible in potential density coordinates, cannot be attributed to Ekman downwelling because the Ekman vertical velocities are much weaker and their meridional structure shares little resemblance to the rapidly varying jet-scale overturning pattern. Instead, the location and structure of these thermally indirect circulations suggest that they are driven by the eddy momentum flux convergence, much like the Ferrel cell in the atmosphere.
AB - The relationship between Antarctic Circumpolar Current jets and eddy fluxes in the Indo-western Pacific Southern Ocean (90°-145°E) is investigated using an eddy-resolving model. In this region, transient eddy momentum flux convergence occurs at the latitude of the primary jet core, whereas eddy buoyancy flux is located over a broader region that encompasses the jet and the interjet minimum. In a small sector (120°-144°E) where jets are especially zonal, a spatial and temporal decomposition of the eddy fluxes further reveals that fast eddies act to accelerate the jet with the maximum eddy momentum flux convergence at the jet center, while slow eddies tend to decelerate the zonal current at the interjet minimum. Transformed Eulerian mean (TEM) diagnostics reveals that the eddy momentum contribution accelerates the jets at all model depths, whereas the buoyancy flux contribution decelerates the jets at depths below ~600 m. In ocean sectors where the jets are relatively well defined, there exist jet-scale overturning circulations with sinking motion on the equatorward flank and a rising motion on the poleward flank of the jets. These jet-scale TEM overturning circulations, which are also discernible in potential density coordinates, cannot be attributed to Ekman downwelling because the Ekman vertical velocities are much weaker and their meridional structure shares little resemblance to the rapidly varying jet-scale overturning pattern. Instead, the location and structure of these thermally indirect circulations suggest that they are driven by the eddy momentum flux convergence, much like the Ferrel cell in the atmosphere.
UR - http://www.scopus.com/inward/record.url?scp=84994155233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84994155233&partnerID=8YFLogxK
U2 - 10.1175/JPO-D-15-0241.1
DO - 10.1175/JPO-D-15-0241.1
M3 - Article
AN - SCOPUS:84994155233
VL - 46
SP - 2943
EP - 2959
JO - Journal of Physical Oceanography
JF - Journal of Physical Oceanography
SN - 0022-3670
IS - 10
ER -