A theoretical discussion of eddy-driven mean flows

Rhines, Peter B.; Holland, William R.

doi:10.1016/0377-0265(79)90015-0

Cited by 178 publications

(134 citation statements)

References 23 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…Eddy PV fluxes are only expected to be purely downgradient in statistically steady flows in regions where the enstrophy (i.e. the variance of the PV) is dissipated, advective and temporal changes in the enstrophy are negligible, and the PV is not being modified by external forcing (Rhines and Holland, 1979;Wilson and Williams, 2003). The experiment presented here is forced and describes a transient process with an eddy (and hence enstrophy) field that exhibits spatial variations over the width of the front.…”

Section: Effect Of the Ite On The Zonal Mean Flowmentioning

confidence: 99%

Formation of intrathermocline eddies at ocean fronts by wind-driven destruction of potential vorticity

Thomas

2008

Dynamics of Atmospheres and Oceans

122

View full text Add to dashboard Cite

A mechanism for the generation of intrathermocline eddies (ITEs) at wind-forced fronts is examined using a high resolution numerical simulation. Favorable conditions for ITE formation result at fronts forced by "down-front" winds, i.e. winds blowing in the direction of the frontal jet. Down-front winds exert frictional forces that reduce the potential vorticity (PV) within the surface boundary in the frontal outcrop, providing a source for the low-PV water that is the materia prima of ITEs.Meandering of the front drives vertical motions that subduct the low-PV water into the pycnocline, pooling it into the coherent anticyclonic vortex of a submesoscale ITE. As the fluid is subducted along the outcropping frontal isopycnal, the low-PV water, which at the surface is associated with strongly baroclinic flow, re-expresses itself as water with nearly zero absolute vorticity. This generation of strong anti-

show abstract

Section: Effect Of the Ite On The Zonal Mean Flowmentioning

confidence: 99%

Formation of intrathermocline eddies at ocean fronts by wind-driven destruction of potential vorticity

Thomas

2008

Dynamics of Atmospheres and Oceans

122

View full text Add to dashboard Cite

show abstract

“…If enstrophy, the time mean of q 2 is maintained, then fluctuations of potential vorticity, q, remain important in that location. The three-dimensional enstrophy balance equation is [52] 1 2…”

Section: Isopycnal Enstrophy and Lagrangian Diffusionmentioning

confidence: 99%

“…For the deep ocean, the correlation between forcing and potential vorticity, −F q , is negligible and only in very rare cases is the correlation of dissipation and potential vorticity, −∆ q , a source of enstrophy [52]. Therefore, down gradient eddy fluxes of potential vorticity are the principal source of enstrophy and are necessary for the sustained presence of eddies in a flow.…”

Section: Isopycnal Enstrophy and Lagrangian Diffusionmentioning

confidence: 99%

“…For A q > 0, eddy fluxes are down the mean gradient, eddies are growing, and there is a source of enstrophy. Rhines and Holland [52] explore the relationship between eddy fluxes of potential vorticity and Lagrangian diffusivity. For the case of mean potential vorticity changing on much larger spatial scales than the particle displacement length scales:…”

Section: Isopycnal Enstrophy and Lagrangian Diffusionmentioning

confidence: 99%

“…The vorticity sink due to dissipation Mean Lagrangian diffusivity of a particle, κ ij = u i (t, p)(x j (t) − x o j ), where x o j is a location where the potential vorticity perturbation of a particle, q , goes to zero [52].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Interior pathways of the North Atlantic meridional overturning circulation

Bower

Lozier

Gary

et al. 2009

Nature

254

249

View full text Add to dashboard Cite

for the AMOC deep limb. In order to assess the impact of the interior pathway relative to the DWBC pathway, this work seeks to quantify the AMOC deep limb pathways in ocean circulation models, compare the pathway signatures of these models to observations, and identify a mechanism driving the interior pathway. The partitioning of the AMOC deep limb into interior and DWBC pathways is observed in several ocean models. Furthermore, there is a good agreement between the structure of the export pathways in models and observations. Both Eulerian and Lagrangian techniques, in models and observations, are used to identify the DWBC and interior pathways and these two perspectives are shown to be compatible with one another.Finally, deep, eddy-driven, recirculation gyres are shown to be a mechanism driving the interior pathway and the existence of the interior pathway is consistent with the vorticity balance at depth. The interior pathway makes a significant contribution to the total transport of the deep limb of the AMOC. Since the interior pathway is much broader and slower than the DWBC pathway, the large-scale transport of climate signals, heat, and anthropogenic CO 2 associated with the AMOC are slower and mixed more broadly throughout the ocean than once thought. iv

show abstract

Stationary mesoscale eddies, upgradient eddy fluxes, and the anisotropy of eddy diffusivity

Lü

Wang

Liu

et al. 2016

Geophysical Research Letters

View full text Add to dashboard Cite

The mesoscale eddies of which parameterization is needed in coarse‐resolution ocean models include not only the transient eddies akin to baroclinic instability but also the stationary eddies associated with topography. By applying a modified Lorenz‐type decomposition to the eddy‐permitting Southern Ocean State Estimate, we show that the stationary mesoscale eddies contribute a significant part to the total eddy kinetic energy, eddy enstrophy, and the total eddy‐induced isopycnal thickness and potential vorticity fluxes. We find that beneath middepth (about 1000 m) the upgradient eddy fluxes, or so‐called “negative” eddy diffusivities, are mainly attributed to the stationary mesoscale eddies, whereas the remaining transient eddy diffusivity is positive, for which the Gent and McWilliams (1990) parameterization scheme applies well. A quantitative method of measuring the anisotropy of eddy diffusivity is presented. The effect of stationary mesoscale eddies is one of major sources responsible for the anisotropy of eddy diffusivity. We suggest that an independent parameterization scheme for stationary mesoscale eddies may be needed for coarse‐resolution ocean models, although the transient eddies remain the predominant part of mesoscale eddies in the oceans.

show abstract

A theoretical discussion of eddy-driven mean flows

Cited by 178 publications

References 23 publications

Formation of intrathermocline eddies at ocean fronts by wind-driven destruction of potential vorticity

Formation of intrathermocline eddies at ocean fronts by wind-driven destruction of potential vorticity

Interior pathways of the North Atlantic meridional overturning circulation

Stationary mesoscale eddies, upgradient eddy fluxes, and the anisotropy of eddy diffusivity

Contact Info

Product

Resources

About