The Role of Eddies in Determining the Structure and Response of the Wind-Driven Southern Hemisphere Overturning: Results from the Modeling Eddies in the Southern Ocean (MESO) Project

doi:10.1175/JPO2980.1

Home
/
Papers
/
The Role of Eddies in Determining the Structure and Response of the Wind-Driven Southern Hemisphere Overturning: Results from the Modeling Eddies in the Southern Ocean (MESO) Project

Journal Article•DOI•

The Role of Eddies in Determining the Structure and Response of the Wind-Driven Southern Hemisphere Overturning: Results from the Modeling Eddies in the Southern Ocean (MESO) Project

Robert Hallberg¹, Anand Gnanadesikan¹•Institutions (1)

Geophysical Fluid Dynamics Laboratory¹

01 Dec 2006-Journal of Physical Oceanography (American Meteorological Society)-Vol. 36, Iss: 12, pp 2232-2252

TL;DR: The Modeling Eddies in the Southern Ocean (MESO) project uses numerical sensitivity studies to examine the role played by Southern Ocean winds and eddies in determining the density structure of the global ocean and the magnitude and structure of global overturning circulation as discussed by the authors.

read less

Abstract: The Modeling Eddies in the Southern Ocean (MESO) project uses numerical sensitivity studies to examine the role played by Southern Ocean winds and eddies in determining the density structure of the global ocean and the magnitude and structure of the global overturning circulation. A hemispheric isopycnal-coordinate ocean model (which avoids numerical diapycnal diffusion) with realistic geometry is run with idealized forcing at a range of resolutions from coarse (2°) to eddy-permitting (1/6°). A comparison of coarse resolutions with fine resolutions indicates that explicit eddies affect both the structure of the overturning and the response of the overturning to wind stress changes. While the presence of resolved eddies does not greatly affect the prevailing qualitative picture of the ocean circulation, it alters the overturning cells involving the Southern Ocean transformation of dense deep waters and light waters of subtropical origin into intermediate waters. With resolved eddies, the surface-t...

...read moreread less

Citations

PDF

Open Access

More filters

Journal Article•DOI•

Wind-Driven Upwelling in the Southern Ocean and the Deglacial Rise in Atmospheric CO2

[...]

Robert F. Anderson¹, Robert F. Anderson², Saleem H. Ali¹, Saleem H. Ali², Louisa I Bradtmiller², Louisa I Bradtmiller¹, Simon H.H. Nielsen³, Martin Q. Fleisher¹, B. E. Anderson¹, Lloyd H. Burckle¹ - Show less +6 more•Institutions (3)

Lamont–Doherty Earth Observatory¹, Columbia University², Florida State University³

13 Mar 2009-Science

TL;DR: In this article, the authors show that opal burial rates and thus upwelling were enhanced during the termination of the last ice age in each sector of the Southern Ocean, and they directly link increased ventilation of deep water to the deglacial rise in atmospheric CO2.

...read moreread less

Abstract: Wind-driven upwelling in the ocean around Antarctica helps regulate the exchange of carbon dioxide (CO2) between the deep sea and the atmosphere, as well as the supply of dissolved silicon to the euphotic zone of the Southern Ocean. Diatom productivity south of the Antarctic Polar Front and the subsequent burial of biogenic opal in underlying sediments are limited by this silicon supply. We show that opal burial rates, and thus upwelling, were enhanced during the termination of the last ice age in each sector of the Southern Ocean. In the record with the greatest temporal resolution, we find evidence for two intervals of enhanced upwelling concurrent with the two intervals of rising atmospheric CO2 during deglaciation. These results directly link increased ventilation of deep water to the deglacial rise in atmospheric CO2.

...read moreread less

993 citations

Journal Article•DOI•

Signatures of the Antarctic ozone hole in Southern Hemisphere surface climate change

[...]

David W. J. Thompson¹, Susan Solomon², Paul J. Kushner³, Matthew H. England⁴, Kevin M. Grise¹, David J. Karoly⁵ - Show less +2 more•Institutions (5)

Colorado State University¹, University of Colorado Boulder², University of Toronto³, University of New South Wales⁴, University of Melbourne⁵

01 Nov 2011-Nature Geoscience

TL;DR: The ozone hole phenomenon was identified and attributed to ozone depletion over Antarctica in a special edition of Nature (http://wwwnaturecom.com/nature/focus/ ozonehole/).

...read moreread less

Abstract: Roughly 90% of atmospheric ozone is found in the lower stratosphere in the ozone layer Since about the 1970s, anthropogenic emissions of ozone-depleting gases have led to depletion of ~3–4% of the total overhead ozone averaged over the globe 1 The strongest depletion is found over Antarctica during spring, when photochemical processes combine with a unique set of meteorological conditions to greatly increase the effectiveness of ozone-depleting gases, and more than half of the total overhead ozone is destroyed Characteristics of the resulting Antarctic ozone hole are reviewed in refs 1 and 2, and the identification and attribution of the phenomenon was recently celebrated in a special edition of Nature (http://wwwnaturecom/nature/focus/ ozonehole/) The Antarctic ozone hole is evident in ozone observations taken every spring since about the early 1980s 1 Its annual onset coincides with the return of sunlight to the cold polar stratosphere during September/October, and its decay with the collapse of the stratospheric vortex during November/December 1,2 The most obvious surface impact is an increase in ultraviolet radiation reaching the surface 1 Over the past decade, however, it has become clear that the ozone hole is also associated with widespread changes in the Southern Hemisphere tropospheric circulation and surface climate Our purpose here is to review the evidence that suggests that the Antarctic ozone hole has had a demonstrable effect on the surface climate of the Southern Hemisphere The ozone hole and Southern Hemisphere circulation Ozone absorbs incoming solar radiation Hence the depletion of ozone over Antarctica leads to cooling of the polar stratosphere 2,3

...read moreread less

820 citations

Journal Article•DOI•

Closure of the meridional overturning circulation through Southern Ocean upwelling

[...]

John Marshall¹, Kevin Speer²•Institutions (2)

Massachusetts Institute of Technology¹, Florida State University²

01 Mar 2012-Nature Geoscience

TL;DR: A review of recent studies emphasizes the importance of wind-driven upwelling in the Southern Ocean for global ocean circulation as discussed by the authors, which plays a central role in the climate and its variability.

...read moreread less

Abstract: The meridional overturning circulation of the ocean plays a central role in the climate and its variability. This Review of recent studies emphasizes the importance of wind-driven upwelling in the Southern Ocean for global ocean circulation.

...read moreread less

799 citations

Journal Article•DOI•

Coordinated Ocean-ice Reference Experiments (COREs)

[...]

Stephen M. Griffies¹, Arne Biastoch, Claus W. Böning, Frank O. Bryan², Gokhan Danabasoglu², Eric P. Chassignet³, Matthew H. England⁴, Rüdiger Gerdes⁵, Helmuth Haak⁶, Robert Hallberg¹, Wilco Hazeleger⁷, Johann H. Jungclaus⁶, William G. Large², Gurvan Madec⁸, Anna Pirani⁹, Bonita L. Samuels¹, Markus Scheinert, Alex Sen Gupta⁴, Camiel Severijns⁷, Harper L. Simmons¹⁰, Anne-Marie Tréguier¹¹, Michael Winton¹, Stephen Yeager², Jianjun Yin³ - Show less +20 more•Institutions (11)

Geophysical Fluid Dynamics Laboratory¹, National Center for Atmospheric Research², Florida State University³, University of New South Wales⁴, Alfred Wegener Institute for Polar and Marine Research⁵, Max Planck Society⁶, Royal Netherlands Meteorological Institute⁷, Centre national de la recherche scientifique⁸, Princeton University⁹, University of Alaska Fairbanks¹⁰, IFREMER¹¹

01 Jan 2009-Ocean Modelling

TL;DR: Coordinated Ocean-ice Reference Experiments (COREs) as mentioned in this paper is a tool to explore the behaviour of global ocean-ice models under forcing from a common atmospheric dataset, which is suitable for our purposes, even though its evaluation originally focussed more on the ocean than on the sea ice.

...read moreread less

654 citations

Journal Article•DOI•

On the driving processes of the Atlantic meridional overturning circulation

[...]

Till Kuhlbrodt¹, Alexa Griesel², Marisa Montoya³, Anders Levermann¹, Matthias Hofmann¹, Stefan Rahmstorf¹ - Show less +2 more•Institutions (3)

Potsdam Institute for Climate Impact Research¹, Scripps Institution of Oceanography², Complutense University of Madrid³

01 Jun 2007-Reviews of Geophysics

TL;DR: In this paper, the authors review both observational data and model results concerning the two main candidates: vertical mixing processes in the ocean's interior and wind-induced Ekman upwelling in the Southern Ocean.

...read moreread less

Abstract: Because of its relevance for the global climate the Atlantic meridional overturning circulation (AMOC) has been a major research focus for many years. Yet the question of which physical mechanisms ultimately drive the AMOC, in the sense of providing its energy supply, remains a matter of controversy. Here we review both observational data and model results concerning the two main candidates: vertical mixing processes in the ocean's interior and wind-induced Ekman upwelling in the Southern Ocean. In distinction to the energy source we also discuss the role of surface heat and freshwater fluxes, which influence the volume transport of the meridional overturning circulation and shape its spatial circulation pattern without actually supplying energy to the overturning itself in steady state. We conclude that both wind-driven upwelling and vertical mixing are likely contributing to driving the observed circulation. To quantify their respective contributions, future research needs to address some open questions, which we outline.

...read moreread less

622 citations

1
2
3
4
…
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92

Collapse

References

PDF

Open Access

More filters

Journal Article•DOI•

Global Sea Floor Topography from Satellite Altimetry and Ship Depth Soundings

[...]

Walter H. F. Smith¹, David T. Sandwell², David T. Sandwell¹•Institutions (2)

National Oceanic and Atmospheric Administration¹, Scripps Institution of Oceanography²

26 Sep 1997-Science

TL;DR: In this paper, a digital bathymetric map of the oceans with a horizontal resolution of 1 to 12 kilometers was derived by combining available depth soundings with high-resolution marine gravity information from the Geosat and ERS-1 spacecraft.

...read moreread less

Abstract: A digital bathymetric map of the oceans with a horizontal resolution of 1 to 12 kilometers was derived by combining available depth soundings with high-resolution marine gravity information from the Geosat and ERS-1 spacecraft. Previous global bathymetric maps lacked features such as the 1600-kilometer-long Foundation Seamounts chain in the South Pacific. This map shows relations among the distributions of depth, sea floor area, and sea floor age that do not fit the predictions of deterministic models of subsidence due to lithosphere cooling but may be explained by a stochastic model in which randomly distributed reheating events warm the lithosphere and raise the ocean floor.

...read moreread less

4,433 citations

"The Role of Eddies in Determining t..." refers methods in this paper

...Thus, at 60°S the 1U2° model has a grid spacing of 27.8 km, while the 1U6° resolution is 9.3 km. Topography was generated using the dataset of Smith and Sandwell (1997) averaged to the grid resolution....
[...]
...Thus, at 60°S the 1⁄2° model has a grid spacing of 27.8 km, while the 1⁄6° resolution is 9.3 km. Topography was generated using the dataset of Smith and Sandwell (1997) averaged to the grid resolution....
[...]

Journal Article•DOI•

Isopycnal mixing in ocean circulation models

[...]

Peter R. Gent¹, James C. McWilliams¹•Institutions (1)

National Center for Atmospheric Research¹

01 Jan 1990-Journal of Physical Oceanography

TL;DR: In this paper, a subgrid-scale form for mesoscale eddy mixing on isopycnal surfaces is proposed for use in non-eddy-resolving ocean circulation models.

...read moreread less

Abstract: A subgrid-scale form for mesoscale eddy mixing on isopycnal surfaces is proposed for use in non-eddy-resolving ocean circulation models. The mixing is applied in isopycnal coordinates to isopycnal layer thickness, or inverse density gradient, as well as to passive scalars, temperature and salinity. The transformation of these mixing forms to physical coordinates is also presented.

...read moreread less

3,107 citations

"The Role of Eddies in Determining t..." refers background or methods in this paper

...The low-resolution model runs (2° and 1°) use an interface height diffusion, which is the equivalent of the Gent and McWilliams (1990) (GM) eddy parameterization....
[...]
...Transient eddies play an important role in this transformation—a role that is not well described by at least one common diffusive eddy parameterization (Gent and McWilliams 1990)....
[...]
...…models, the effect of mesoscale eddies is often parameterized in terms of a diffusive tracer flux along isopycnals (Redi 1982; Griffies et al. 1998) and an advective flux resulting from a diffusive smoothing of isopycnal depths (Gent and McWilliams 1990; Gent et al. 1995; Visbeck et al. 1997)....
[...]

Journal Article•DOI•

The oceans : their physics, chemistry, and general biology

[...]

Harald Ulrik Sverdrup, Martin W. Johnson, Richard H. Fleming

31 Dec 1943-Copeia

TL;DR: The book is intended to provide a good deal of factual information, but above all it should be an aid to the beginner and specialist alike in the coordination of the various fields of oceanography.

...read moreread less

Abstract: Four years ago when we started the preparation of this book, we hoped to give a survey of well-established oceanographic knowledge, but it soon became apparent that the book could not be brought up to date without summarizing and synthesizing the wealth of information that has been acquired within the past dozen years, as well as the many new ideas that have been advanced. Consequently, the book has grown far beyond its originally planned scope, and the presentation has become colored by the personal concepts of the authors. Discussion of many topics, such as the absorption of radiation in the sea, the relations of organisms to the chemical composition of sea water, or the productivity of the sea, has led to tentative conclusions that are perhaps presented here as better substantiated than is actually the case. At the risk of premature generalizations we have, however, preferred definite statements to mere enumeration o uncorrelated observations and conflicting interpretations, believing that the treatment selected would be more stimulating.The book is intended to provide a good deal of factual information, but above all it should be an aid to the beginner and specialist alike in the coordination of the various fields of oceanography. The lists of literature at the ends of chapters are not intended to be exhaustive, but will serve as guides to recent publications. When possible, reference is made to books containing comprehensive bibliographies rather than to original papers.

...read moreread less

1,738 citations

"The Role of Eddies in Determining t..." refers background in this paper

...The water masses that compose the vast majority of the ocean volume are either formed, modified, or transit through the Southern Ocean (Sverdrup et al. 1942; Schmitz 1996; Doney et al. 1998)....
[...]
...It has long been known that eddies must be of leading-order importance in the Southern Ocean momentum balance, and that the World Ocean is largely filled by water masses that originate or are eroded in the Southern Ocean (Sverdrup et al. 1942)....
[...]

Journal Article•DOI•

Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data

[...]

Alexandre Ganachaud¹, Carl Wunsch•Institutions (1)

IFREMER¹

23 Nov 2000-Nature

TL;DR: These estimates provide a new reference state for future climate studies with rigorous estimates of the uncertainties, and resolve globally vertical mixing across surfaces of equal density.

...read moreread less

Abstract: Through its ability to transport large amounts of heat, fresh water and nutrients, the ocean is an essential regulator of climate. The pathways and mechanisms of this transport and its stability are critical issues in understanding the present state of climate and the possibilities of future changes. Recently, global high-quality hydrographic data have been gathered in the World Ocean Circulation Experiment (WOCE), to obtain an accurate picture of the present circulation. Here we combine the new data from high-resolution trans-oceanic sections and current meters with climatological wind fields, biogeochemical balances and improved a priori error estimates in an inverse model, to improve estimates of the global circulation and heat fluxes. Our solution resolves globally vertical mixing across surfaces of equal density, with coefficients in the range (3-12) x 10(-4) m2 s(-1). Net deep-water production rates amount to (15 +/- 12) x 10(6) m3 s(-1) in the North Atlantic Ocean and (21 +/- 6) x 10(6) m3 s(-1) in the Southern Ocean. Our estimates provide a new reference state for future climate studies with rigorous estimates of the uncertainties.

...read moreread less

1,133 citations

"The Role of Eddies in Determining t..." refers methods in this paper

...While the simulations here exhibit roughly 20 Sv of AAIW formation from denser waters, as compared with the 14 Sv proposed by Schmitz (1996), an inverse model by Ganachaud and Wunsch (2000) finds only 8–9 Sv of net conversion....
[...]

Journal Article•DOI•

Oceanic Isopycnal Mixing by Coordinate Rotation

[...]

M. H. Redi¹•Institutions (1)

Princeton University¹

01 Oct 1982-Journal of Physical Oceanography

TL;DR: In this article, the effect of anisotropic turbulence as diffusive transport along and across density surfaces was modeled by transforming the mixing tensor from a diagonal second-rank tensor in the isopycnal coordinate system to a tensor containing off-diagonal elements in the geopotential coordinate system.

...read moreread less

Abstract: Current numerical models of oceanic circulation differentiate between the eddy diffusion and viscosity transport along the geopotential horizontal and vertical directions only. In order to model the effect of anisotropic turbulence as diffusive transport along and across density surfaces, the isopycnal mixing tensor has been transformed from a diagonal second-rank tensor in the isopycnal coordinate system to a tensor containing off-diagonal elements in the geopotential coordinate system.

...read moreread less

993 citations

"The Role of Eddies in Determining t..." refers background in this paper

...…models, the effect of mesoscale eddies is often parameterized in terms of a diffusive tracer flux along isopycnals (Redi 1982; Griffies et al. 1998) and an advective flux resulting from a diffusive smoothing of isopycnal depths (Gent and McWilliams 1990; Gent et al. 1995; Visbeck et al. 1997)....
[...]
...In large-scale ocean models, the effect of mesoscale eddies is often parameterized in terms of a diffusive tracer flux along isopycnals (Redi 1982; Griffies et al. 1998) and an advective flux resulting from a diffusive smoothing of isopycnal depths (Gent and McWilliams 1990; Gent et al. 1995; Visbeck et al. 1997)....
[...]
...Transient eddies play an important role in this transformation—a role that is not well described by at least one common diffusive eddy parameterization (Gent and McWilliams 1990)....
[...]
...In large-scale ocean models, the effect of mesoscale eddies is often parameterized in terms of a diffusive tracer flux along isopycnals (Redi 1982; Griffies et al. 1998) and an advective flux resulting from a diffusive smoothing of isopycnal depths (Gent and McWilliams 1990; Gent et al. 1995;…...
[...]
...The low-resolution model runs (2° and 1°) use an interface height diffusion, which is the equivalent of the Gent and McWilliams (1990) (GM) eddy parameterization....
[...]