DOI: 10.5061/dryad.55bp8
title: Data from: Isopycnal mixing suppression by the Antarctic Circumpolar Current and the Southern Ocean Meridional Overturning Circulation

description: The meridional overturning circulation (MOC) in the Southern Ocean is
 investigated using hydrographic observations combined with satellite
 measurements of sea surface height. A three-dimensional (spatial and
 vertical) estimate of the isopycnal eddy diffusivity in the Southern Ocean
 is obtained using the theory of Ferrari and Nikurashin that includes the
 influence of suppression of the diffusivity by the strong, time-mean
 flows. It is found that the eddy diffusivity is enhanced at depth,
 reaching a maximum at the critical layer near 1000 m. The estimate of
 diffusivity is used with a simple diffusive parameterization to estimate
 the meridional eddy volume flux. This estimate of eddy volume flux is
 combined with an estimate of the Ekman transport to reconstruct the
 time-mean overturning circulation. By comparing the reconstruction with,
 and without, suppression of the eddy diffusivity by the mean flow, the
 influence of the suppression on the overturning is illuminated. It is
 shown that the suppression of the eddy diffusivity results in a large
 reduction of interior eddy transports and a more realistic eddy-induced
 overturning circulation. Finally, a simple conceptual model is used to
 show that the MOC is influenced not only by the existence of enhanced
 diffusivity at depth but also by the details of the vertical structure of
 the eddy diffusivity, such as the depth of the critical layer.
description: mapped_gamma_all_sources_2005Neutral Density (Jackett & McDougall, 1997) for the year 2005 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2006Neutral Density (Jackett & McDougall, 1997) for the year 2006 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2007Neutral Density (Jackett & McDougall, 1997) for the year 2007 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2008Neutral Density (Jackett & McDougall, 1997) for the year 2008 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2009Neutral Density (Jackett & McDougall, 1997) for the year 2009 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2010Neutral Density (Jackett & McDougall, 1997) for the year 2010 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2011Neutral Density (Jackett & McDougall, 1997) for the year 2010 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2012Neutral Density (Jackett & McDougall, 1997) for the year 2012 (with annual and semi-annual harmonics) from 75S to 30S.mapped_gamma_all_sources_2013Neutral Density (Jackett & McDougall, 1997) for the year 2013 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2005The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2005 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2006The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2006 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2007The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2007 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2008The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2008 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2009The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2009 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2010The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2010 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2011The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2011 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2012The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2012 (with annual and semi-annual harmonics) from 75S to 30S.mapped_pv_all_sources_2013The potential vorticity calculated from the vertical gradient of the neutral density (ie. PV = f/rho_0 d(gamma)/dz) for the year 2013 (with annual and semi-annual harmonics) from 75S to 30S.mapped_streamfunction_abs_all_sources_2006The absolute geostrophic streamfunction on depth surfaces for the year 2006 (including annual and semi-annual harmonics), caluculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_all_sources_2007The absolute geostrophic streamfunction on depth surfaces for the year 2007 (including annual and semi-annual harmonics), caluculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_all_sources_2008The absolute geostrophic streamfunction on depth surfaces for the year 2008 (including annual and semi-annual harmonics), caluculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_all_sources_2009The absolute geostrophic streamfunction on depth surfaces for the year 2009 (including annual and semi-annual harmonics), calculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_all_sources_2010The absolute geostrophic streamfunction on depth surfaces for the year 2010 (including annual and semi-annual harmonics), caluculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_all_sources_2011The absolute geostrophic streamfunction on depth surfaces for the year 2011 (including annual and semi-annual harmonics), caluculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_all_sources_2012The absolute geostrophic streamfunction on depth surfaces for the year 2012 (including annual and semi-annual harmonics), caluculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_all_sources_2013The absolute geostrophic streamfunction on depth surfaces for the year 2013 (including annual and semi-annual harmonics), caluculated using the TEOS-10 routine gsw_geo_strf_dyn_height (McDougall & Barker 2011).mapped_streamfunction_abs_gamma_all_sources_26_2005The absolute geostrophic streamfunction on isopycnal surfaces for the year 2005 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2006_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2006 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2007_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2007 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2008_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2008 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2009_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2009 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2010_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2010 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2011_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2011 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2012_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2012 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).mapped_streamfunction_abs_gamma_all_sources_26_2013_no_cycleThe absolute geostrophic streamfunction on isopycnal surfaces for the year 2013 (including annual harmonics but NO semi-annual harmonics due to file size constraints), caluculated using the TEOS-10 routine gsw_geo_strf_isopycnal that implements the approximate streamfunction of (McDougall & Klocker 2010).Diffusion_Coefficients_FilteredThe cross-stream diffusivity in the Southern Ocean (75S to 30S) for the period 2005 to 2015. The diffusion coefficients are calculated using the theory of Ferrari and Nikurashin (2010). The dataset includes the suppressed and unsupressed diffusivities, as well as the supression factor (the ratio of the unsuppressed and suppressed diffusivity)