On Constraining the Mesoscale Eddy Energy Dissipation Time‐Scale

Mak, Julian; Avdis, Alexandros; W., David, Tomos; Lee, H. S.; Na, Y.; Wang, Yan; Yan, F. E.

doi:10.1029/2022ms003223

Cited by 10 publications

(14 citation statements)

References 99 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All calculations were spun up from rest at the relevant horizontal resolutions with κ gm = 0 to the end of model year 500, and perturbation experiments were performed from start of model year 501 to end of model year 810, where the time-averaging period is the last 10 years (start of model year 801 to end of model year 810). All the GEOMETRIC-based calculations here employ the same parameter values, given in Table 1; the choice of α and λ is on the larger side to previous reported works, but the value of λ is not inconsistent with the estimates for the Southern Ocean derived from an inverse calculation (Mak, Avdis, et al, 2022).…”

Section: Model Setupmentioning

confidence: 99%

“…The parameterized eddy energy is diffused in the horizontal (Grooms, 2015; Ni, Zhai, Wang, & Hughes, 2020; Ni, Zhai, Wang, & Marshall, 2020) with a diffusivity η E . A linear dissipation of the parameterized eddy energy at rate λ is employed (with minimum parameterized eddy energy level E 0 ), so λ −1 is an time‐scale, and is a bulk parameterization of energy fluxes out of the mesoscales resulting from numerous dynamical processes (e.g., Mak, Avdis, et al., 2022).…”

Section: The Gm Scheme and The Splitting Approachmentioning

confidence: 99%

See 1 more Smart Citation

Scale‐Awareness in an Eddy Energy Constrained Mesoscale Eddy Parameterization

Mak,

Maddison,

Marshall

et al. 2023

J Adv Model Earth Syst

Self Cite

View full text Add to dashboard Cite

There is an increasing interest in mesoscale eddy parameterizations that are scale‐aware, normally interpreted to mean that a parameterization does not require parameter recalibration as the model resolution changes. Here we examine whether Gent–McWilliams (GM) based version of GEOMETRIC, a mesoscale eddy parameterization that is constrained by a parameterized eddy energy budget, is scale‐aware in its energetics. It is generally known that GM‐based schemes severely damp out explicit eddies, so the parameterized component would be expected to dominate across resolutions, and we might expect a negative answer to the question of energetic scale‐awareness. A consideration of why GM‐based schemes damp out explicit eddies leads a suggestion for what we term a splitting procedure: a definition of a “large‐scale” field is sought, and the eddy‐induced velocity from the GM‐scheme is computed from and acts only on the large‐scale field, allowing explicit and parameterized components to co‐exist. Within the context of an idealized re‐entrant channel model of the Southern Ocean, evidence is provided that the GM‐based version of GEOMETRIC is scale‐aware in the energetics as long as we employ a splitting procedure. The splitting procedure also leads to an improved representation of mean states without detrimental effects on the explicit eddy motions.

show abstract

Section: Model Setupmentioning

confidence: 99%

Section: The Gm Scheme and The Splitting Approachmentioning

confidence: 99%

Scale‐Awareness in an Eddy Energy Constrained Mesoscale Eddy Parameterization

Mak,

Maddison,

Marshall

et al. 2023

J Adv Model Earth Syst

Self Cite

View full text Add to dashboard Cite

show abstract

“…Klocker and Abernathey 2014;Groeskamp et al 2020). The value of 𝛾 could possibly be inferred from an inverse method, like that employed in Mak et al (2022a) for the mesoscale eddy energy dissipation timescale. Another option could be to determine 𝛾 from the autocorrelation of observational velocity timeseries.…”

Section: A Relevance Of Eddy Length and Time Scalesmentioning

confidence: 99%

Suppression of mesoscale eddy mixing by topographic PV gradients

Sterl,

Lacasce,

Groeskamp

et al. 2024

Preprint

View full text Add to dashboard Cite

Large oceanic 'whirls', called eddies, can mix and transport ocean properties such as heat, salt, carbon and nutrients. Mixing plays an important role for oceanic ecosystems and the climate system. In numerical simulations of the Earth's climate, eddy mixing is typically represented using a simplified expression. However, an effect that is often not included is that eddy mixing is weaker over a sloping seafloor. In most areas of the ocean the bottom slope is steep enough for this effect to be significant. In this study we derive an expression for eddy mixing that accounts for oceanic bottom slopes. The present effort provides a physical basis for eddy mixing over oceanic bottom slopes, justifying their use in climate models.

show abstract

“…This estimate can be compared to the work of Mak, Avdis, et al (2022) who constrain the same eddy dissipation timescale using a kinematic inverse calculation inferred from an eddy permitting ocean circulation model. Similarly, short timescales are found near the western boundary currents and the ACC while subtropical gyre signatures are absent from their spatial distribution.…”

Section: The Eddy Dissipation Timescalementioning

confidence: 99%

Global Estimation of the Eddy Kinetic Energy Dissipation From a Diagnostic Energy Balance

Torres,

Waldman,

Mak

et al. 2023

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

Mesoscale eddies dominate the ocean kinetic energy reservoir. However, how and where this energy flows out from the mesoscale remains uncertain. Here, a simplified mesoscale energy budget is used where sources due to baroclinic instability are balanced by all the dissipative processes approximated as a linear damping rate. In this simple model, the eddy kinetic energy (EKE) dissipation is computed from a climatological mean field of density and satellite altimeter data, and is proportional to an eddy efficiency parameter α. Assuming an eddy efficiency of α = 0.1, we find a global EKE dissipation rate of 0.66 ± 0.19 TW. The results show an intense dissipation near western boundary currents and in the Antarctic Circumpolar Current, where both large levels of energy and baroclinic conversion occur. The resulting geographical distribution of the dissipation rate brings new insights for closing the ocean kinetic energy budget, as well as constraining future mesoscale parameterizations and associated mixing processes.

show abstract

On Constraining the Mesoscale Eddy Energy Dissipation Time‐Scale

Abstract: The ocean, being a key component of the Earth system, plays a central role in the Earth's energy and biogeochemical cycles through its ability to store and transport large amounts of tracers (e.g.,

Cited by 10 publications

References 99 publications

Scale‐Awareness in an Eddy Energy Constrained Mesoscale Eddy Parameterization

Scale‐Awareness in an Eddy Energy Constrained Mesoscale Eddy Parameterization

Suppression of mesoscale eddy mixing by topographic PV gradients

Global Estimation of the Eddy Kinetic Energy Dissipation From a Diagnostic Energy Balance

Contact Info

Product

Resources

About