NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
An Assessment of Antarctic Circumpolar Current and Southern Ocean Meridional Overturning Circulation During 1958-2007 in a Suite of Interannual CORE-2 SimulationsIn the framework of the second phase of the Coordinated Ocean-ice Reference Experiments (CORE-II), we present an analysis of the representation of the Antarctic Circumpolar Current (ACC) and Southern Ocean Meridional Overturning Circulation (MOC) in a suite of seventeen global ocean-sea ice models. We focus on the mean, variability and trends of both the ACC and MOC over the 19582007 period, and discuss their relationship with the surface forcing. We aim to quantify the degree of eddy saturation and eddy compensation in the models participating in CORE-II, and compare our results with available observations, previous fine-resolution numerical studies and theoretical constraints. Most models show weak ACC transport sensitivity to changes in forcing during the past five decades, and they can be considered to be in an eddy saturated regime. Larger contrasts arise when considering MOC trends, with a majority of models exhibiting significant strengthening of the MOC during the late 20th and early 21st century. Only a few models show a relatively small sensitivity to forcing changes, responding with an intensified eddy-induced circulation that provides some degree of eddy compensation, while still showing considerable decadal trends. Both ACC and MOC interannual variability are largely controlled by the Southern Annular Mode (SAM). Based on these results, models are clustered into two groups. Models with constant or two-dimensional (horizontal) specification of the eddy-induced advection coefficient show larger ocean interior decadal trends, larger ACC transport decadal trends and no eddy compensation in the MOC. Eddy-permitting models or models with a three-dimensional time varying show smaller changes in isopycnal slopes and associated ACC trends, and partial eddy compensation. As previously argued, a constant in time or space is responsible for a poor representation of mesoscale eddy effects and cannot properly simulate the sensitivity of the ACC and MOC to changing surface forcing. Evidence is given for a larger sensitivity of the MOC as compared to the ACC transport, even when approaching eddy saturation. Future process studies designed for disentangling the role of momentum and buoyancy forcing in driving the ACC and MOC are proposed.
Document ID
20160000358
Acquisition Source
Goddard Space Flight Center
Document Type
Accepted Manuscript (Version with final changes)
Authors
Riccardo Farneti
(International Centre for Theoretical Physics Trieste, Italy)
Armando Howard
(Goddard Institute for Space Studies New York, New York, United States)
Maxwell Kelley
(Goddard Institute for Space Studies New York, New York, United States)
Stephanie M Downes
(Australian National University Canberra, Australian Capital Territory, Australia)
Stephen M Griffies
(National Oceanic and Atmospheric Administration Washington D.C., District of Columbia, United States)
Simon J Marsland
(Centre for Australian Weather and Climate Research Aspendale, Australia)
Erik Behrens
(GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel, Germany)
Mats Bentsen
(Uni Research Ltd Bergen, Norway)
Daohua Bi
(Centre for Australian Weather and Climate Research Aspendale, Australia)
Arne Biastoh
(GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel, Germany)
Claus Boening
(GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel, Germany)
Alexandra Bozec
(Center for Ocean-Atmospheric Prediction Studies (COAPS) Tallahassee, FL, United States)
Vittorio M Canuto
(Goddard Institute for Space Studies New York, New York, United States)
Eric Chassignet
(Center for Ocean-Atmospheric Prediction Studies (COAPS) Tallahassee, FL, United States)
Gokhan Danabasoqlu
(National Center for Atmospheric Research Boulder, Colorado, United States)
Sergey Danilov
(Alfred-Wegener-Inst. for Polar and Marine Research Bremerhaven, Germany)
Nikolay Diansky
(Academy of Sciences (Russia) Moscow, Russian Federation)
Helge Drange
(University of Bergen Bergen, Hordaland, Norway)
Giuseppe Fogli Pier
(Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC) Bologna, Italy)
Anatoly Gusev
(Academy of Sciences (Russia) Moscow, Russian Federation)
Robert W Hallberg
(National Oceanic and Atmospheric Administration Washington D.C., District of Columbia, United States)
Armando Howard
(City University of New York New York, New York, United States)
Mehmet Ilicak
(Uni Research Ltd Bergen, Norway)
Thomas Jung
(Alfred Wegener Institute for Polar and Marine Research Bremerhaven, Germany)
Maxwell Kelley
(Goddard Institute for Space Studies New York, New York, United States)
William G Large
(National Center for Atmospheric Research Boulder, Colorado, United States)
Anthony Leboissetier
(Goddard Institute for Space Studies New York, New York, United States)
Matthew Long
(National Center for Atmospheric Research Boulder, Colorado, United States)
Jianhua Lu
(Center for Ocean-Atmospheric Prediction Studies (COAPS) Tallahassee, FL, United States)
Simona Masina
(Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC) Bologna, Italy)
Akhilesh Mishra
(Center for Ocean-Atmospheric Prediction Studies (COAPS) Tallahassee, FL, United States)
Antonio Navarra
(Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC) Bologna, Italy)
A J George Nurser
(National Oceanography Centre Southampton (NOCS) Southampton, United Kingdom)
Lavinia Patara
(GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel, Germany)
Bonita L Samuels
(National Oceanic and Atmospheric Administration Washington D.C., District of Columbia, United States)
Dmitry Sidorenko
(Alfred Wegener Institute for Polar and Marine Research Bremerhaven, Germany)
Hiroyuki Tsujino
(Meteorological Research Institute Tokyo, Japan)
Petteri Uotila
(Centre for Australian Weather and Climate Research Aspendale, Australia)
Qiang Wang
(Alfred Wegener Institute for Polar and Marine Research Bremerhaven, Germany)
Steve G Yeager
(National Center for Atmospheric Research Boulder, Colorado, United States)
Date Acquired
January 6, 2016
Publication Date
July 30, 2015
Publication Information
Publication: Ocean Modelling
Publisher: Elsevier
Volume: 93
Issue Publication Date: September 1, 2015
ISSN: 1463-5003
Subject Category
Oceanography
Report/Patent Number
GSFC-E-DAA-TN25877
Funding Number(s)
WBS: WBS 509496.02.08.04.24
CONTRACT_GRANT: NNG12HP07C
Distribution Limits
Public
Copyright
Portions of document may include copyright protected material.
Keywords
Southern Ocean dynamics
Southern Ocean meridional overturning circulation
Global ocean-sea ice modelling
Model comparisons
Antarctic Circumpolar Current
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available