Global interior eddy available potential energy diagnosed from Argo floats

Roullet, Guillaume; Capet, Xavier; Maze, Guillaume

doi:10.1002/2013gl059004

Cited by 44 publications

(62 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared to EKE, it shows a more significant increase downstream of the Charleston Bump, and it peaks at the upon-separation region. The resemblance of the horizontal structure between EPE and EKE was also found in the global EPE map constructed from the Argo profiles by Roullet et al (2014). For the entire GS domain, the EPE reservoir is 71.48 PJ, which is smaller than the EKE reservoir.…”

Section: Summary and Discussionmentioning

confidence: 62%

See 1 more Smart Citation

Energetics of Eddy–Mean Flow Interactions in the Gulf Stream Region

Kang

Curchitser

2015

Journal of Physical Oceanography

119

139

View full text Add to dashboard Cite

A detailed energetics analysis of the Gulf Stream (GS) and associated eddies is performed using a highresolution multidecadal regional ocean model simulation. The energy equations for the time-mean and timevarying flows are derived as a theoretical framework for the analysis. The eddy-mean flow energy components and their conversions show complex spatial distributions. In the along-coast region, the cross-stream and cross-bump variations are seen in the eddy-mean flow energy conversions, whereas in the off-coast region, a mixed positive-negative conversion pattern is observed. The local variations of the eddy-mean flow interaction are influenced by the varying bottom topography. When considering the domain-averaged energetics, the eddy-mean flow interaction shows significant along-stream variability. Upstream of Cape Hatteras, the energy is mainly transferred from the mean flow to the eddy field through barotropic and baroclinic instabilities. Upon separating from the coast, the GS becomes highly unstable and both energy conversions intensify. When the GS flows into the off-coast region, an inverse conversion from the eddy field to the mean flow dominates the power transfer. For the entire GS region, the mean current is intrinsically unstable and transfers 28.26 GW of kinetic energy and 26.80 GW of available potential energy to the eddy field. The mesoscale eddy kinetic energy is generated by mixed barotropic and baroclinic instabilities, contributing 28.26 and 9.15 GW, respectively. Beyond directly supplying the barotropic pathway, mean kinetic energy also provides 11.55 GW of power to mean available potential energy and subsequently facilitates the baroclinic instability pathway.

show abstract

Section: Summary and Discussionmentioning

confidence: 62%

“…4c). Roullet et al (2014) recently derived a 3D global EPE map from the Argo profiles and showed that the horizontal structure of the subsurface EPE is very close to that of the surface EKE for the global ocean.…”

Section: Energy Reservoirsmentioning

confidence: 99%

Energetics of Eddy–Mean Flow Interactions in the Gulf Stream Region

Kang

Curchitser

2015

Journal of Physical Oceanography

119

139

View full text Add to dashboard Cite

show abstract

“…Comparison with Roullet's (2014) fluctuating APE estimate Figure 6 shows the distribution of fluctuating APE density at the surface and at 250-, 500-, and 1000-m depths [the same depths used in Fig. 2 of Roullet (2014)].…”

Section: Resultsmentioning

confidence: 99%

Available Potential Energy and the General Circulation: Partitioning Wind, Buoyancy Forcing, and Diapycnal Mixing

Zemskova

White

Scotti

2015

Journal of Physical Oceanography

View full text Add to dashboard Cite

The ocean energy cycle is calculated using a new available potential energy (APE) decomposition, which partitions adiabatic buoyancy fluxes from diapycnal mixing, applied to results from the Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2), eddy-permitting ocean state estimate and observed surface buoyancy fluxes from the WHOI OAFlux project. Compared with the traditional Lorenz energy cycle, this framework provides a more accurate estimate of the background potential energy (PE) of the global oceans and the surface generation and interior fluxes of APE. Calculations of the global energy budget using 16 yr of ECCO2 output suggest that the adiabatic portion of the general circulation is maintained by a balance between the mean wind-driven upwelling that increases APE (10.27 TW) and time-fluctuating processes, including mesoscale eddies, which release APE (20.27 TW). The APE generated by surface buoyancy fluxes (0.46 TW) is comparable to the generation by the mean winds. The global rate of irreversible mixing (0.46 TW), which balances surface APE generation, is consistent with previous estimates of the diapycnal fluxes associated with maintaining deep stratification (see Munk and Wunsch) and a global diapycnal diffusivity of O(1 3 10 24 ) m 2 s 21 . However, the net contribution of diapycnal mixing to the total potential energy is negligible, which suggests that mixing, contrary to one current paradigm, does not place a global demand on kinetic energy dissipation. However, there are regions where mixing is significant, for example, between 3000 and 5000 m (in ECCO2), where mixing increases PE by 0.1 TW. The work provides a new framework for separating adiabatic-diabatic fluxes and for monitoring the global rate of diapycnal mixing rate using measurable surface properties such as SST and heat flux.

show abstract

“…Depths, at which eddies seem responsible for the biggest part of local EKE, can actually vary with the latitude. An independent benchmark of the ocean interior turbulence has been recently provided by Roullet et al (2014) from the analysis of the Argo density profile down to 2000 m. They evaluate the eddy available potential nnergy (EAPE) generated by the anomalous vertical isopycnal displacements with respect to the stationary, long-term value at different depths. In particular, the interior maxima of EAPE extracted by Argo floats in several ocean areas, suggest the presence of local energy source at depths.…”

Section: Reke Vertical Profilesmentioning

confidence: 99%

Benchmarking the mesoscale variability in global ocean eddy-permitting numerical systems

et al. 2017

View full text Add to dashboard Cite

The role of data assimilation procedures on representing ocean mesoscale variability is assessed by applying eddy statistics to a state-of-the-art global ocean reanalysis (C-GLORS), a free global ocean simulation (performed with the NEMO system) and an observation-based dataset (ARMOR3D) used as an independent benchmark. Numerical results are computed on a 1/4 • horizontal grid (ORCA025) and share the same resolution with ARMOR3D dataset. This "eddy-permitting" resolution is sufficient to allow ocean eddies to form. Further to assessing the eddy statistics from three different datasets, a global threedimensional eddy detection system is implemented in order to bypass the need of regional-dependent definition of thresholds, typical of commonly adopted eddy detection algorithms. It thus provides full three-dimensional eddy Istituto Nazionale di Geofisica e Vulcanologia (INGV), Bologna, Italy statistics segmenting vertical profiles from local rotational velocities. This criterion is crucial for discerning real eddies from transient surface noise that inevitably affects any twodimensional algorithm. Data assimilation enhances and corrects mesoscale variability on a wide range of features that cannot be well reproduced otherwise. The free simulation fairly reproduces eddies emerging from western boundary currents and deep baroclinic instabilities, while underestimates shallower vortexes that populate the full basin. The ocean reanalysis recovers most of the missing turbulence, shown by satellite products , that is not generated by the model itself and consistently projects surface variability deep into the water column. The comparison with the statistically reconstructed vertical profiles from ARMOR3D show that ocean data assimilation is able to embed variability into the model dynamics, constraining eddies with in situ and altimetry observation and generating them consistently with local environment.

show abstract

Global interior eddy available potential energy diagnosed from Argo floats

Cited by 44 publications

References 17 publications

Energetics of Eddy–Mean Flow Interactions in the Gulf Stream Region

Energetics of Eddy–Mean Flow Interactions in the Gulf Stream Region

Available Potential Energy and the General Circulation: Partitioning Wind, Buoyancy Forcing, and Diapycnal Mixing

Benchmarking the mesoscale variability in global ocean eddy-permitting numerical systems

Contact Info

Product

Resources

About