58 citations · 495 across the 27 of their papers we have counts for
27 papers
Formulation and calibration of CATKE, a one-equation parameterization for microscale ocean mixing
Gregory LeClaire Wagner, Adeline Hillier, Navid C. Constantinou +7
We describe CATKE, a parameterization for fluxes associated with small-scale or "microscale" ocean turbulent mixing on scales between 1 and 100 meters. CATKE uses a downgradient fo…
Intrinsically episodic Antarctic shelf intrusions of circumpolar deep water via canyons
Ellie Q. Y. Ong, Edward Doddridge, Navid C. Constantinou +2
The structure of the Antarctic Slope Current at the continental shelf is crucial in governing the poleward transport of warm water. Canyons on the continental slope may provide a p…
Surface heating steers planetary-scale ocean circulation
Dhruv Bhagtani, Andrew McColl Hogg, Ryan Mahony Holmes +1
Gyres are central features of large-scale ocean circulation and are involved in transporting tracers such as heat, nutrients, and carbon-dioxide within and across ocean basins. Tra…
Nusselt number scaling in horizontal convection
Navid C. Constantinou, Cesar B. Rocha, Stefan G. Llewellyn Smith +1
We report a numerical study of horizontal convection (HC) at Prandtl number , with both no-slip and free-slip boundary conditions. We obtain 2D and 3D solutions and determi…
Eigenvalue initialisation and regularisation for Koopman autoencoders
Jack W. Miller, Charles O'Neill, Navid C. Constantinou +1
Regularising the parameter matrices of neural networks is ubiquitous in training deep models. Typical regularisation approaches suggest initialising weights using small random valu…
Stokes drift should not be added to ocean general circulation model velocities
Gregory LeClaire Wagner, Navid C. Constantinou, Brandon G. Reichl
Studies of ocean surface transport often invoke the "Eulerian-mean hypothesis": that wave-agnostic general circulation models neglecting explicit surface waves effects simulate the…
How winds and ocean currents influence the drift of floating objects
Till J. W. Wagner, Ian Eisenman, Amanda M. Ceroli +1
Arctic icebergs, unconstrained sea ice floes, oil slicks, mangrove drifters, lost cargo containers, and other flotsam are known to move at 2-4% of the prevailing wind velocity rela…
Intrinsic oceanic decadal variability of upper-ocean heat content
Navid C. Constantinou, Andrew McC. Hogg
Atmosphere and ocean are coupled via air-sea interactions. The atmospheric conditions fuel the ocean circulation and its variability, but the extent to which ocean processes can af…
Cause-and-effect of linear mechanisms sustaining wall turbulence
Adrián Lozano-Durán, Navid C. Constantinou, Marios-Andreas Nikolaidis +1
Despite the nonlinear nature of turbulence, there is evidence that part of the energy-transfer mechanisms sustaining wall turbulence can be ascribed to linear processes. The differ…
Alternative physics to understand wall turbulence: Navier-Stokes equations with modified linear dynamics
Adrán Lozano-Durán, Marios-Andreas Nikolaidis, Navid C. Constantinou +1
Despite the nonlinear nature of wall turbulence, there is evidence that the energy-injection mechanisms sustaining wall turbulence can be ascribed to linear processes. The differen…
The Nusselt numbers of horizontal convection
Cesar. B. Rocha, Navid C. Constantinou, Stefan G. Llewellyn Smith +1
We consider the problem of horizontal convection in which non-uniform buoyancy, , is imposed on the top surface of a container and all other surfaces are insulating…
Wall turbulence without modal instability of the streaks
Adrián Lozano-Durán, Marios-Andreas Nikolaidis, Navid C. Constantinou +1
Despite the nonlinear nature of wall turbulence, there is evidence that the mechanism underlying the energy transfer from the mean flow to the turbulent fluctuations can be ascribe…
Eddy saturation of the Southern Ocean: a baroclinic versus barotropic perspective
Navid C. Constantinou, Andrew McC. Hogg
"Eddy saturation" is the regime in which the total time-mean volume transport of an oceanic current is relatively insensitive to the wind stress forcing and is often invoked as a d…
Kinetic energy of eddy-like features from sea surface altimetry
Josué Martínez-Moreno, Andrew McC. Hogg, Andrew E. Kiss +2
The mesoscale eddy field plays a key role in the mixing and transport of physical and biological properties and redistribute energy budgets in the ocean. Eddy kinetic energy is com…
Wall turbulence with constrained energy extraction from mean flow
Adrián Lozano-Durán, Michael Karp, Navid. C. Constantinou
We study the mechanism of energy injection from the mean flow to the fluctuating velocity necessary to maintain wall turbulence. This process is believed to be correctly represente…
Magnetic eddy viscosity of mean shear flows in two-dimensional magnetohydrodynamics
Jeffrey B. Parker, Navid C. Constantinou
Magnetic induction in magnetohydrodynamic fluids at magnetic Reynolds number (Rm) less than~1 has long been known to cause magnetic drag. Here, we show that when $\mathrm{Rm} \gg 1…
Magnetic suppression of zonal flows on a beta plane
Navid C. Constantinou, Jeffrey B. Parker
Zonal flows in rotating systems have been previously shown to be suppressed by the imposition of a background magnetic field aligned with the direction of rotation. Understanding t…
Statistical state dynamics of weak jets in barotropic beta-plane turbulence
Nikolaos A. Bakas, Navid C. Constantinou, Petros J. Ioannou
Zonal jets in a barotropic setup emerge out of homogeneous turbulence through a flow-forming instability of the homogeneous turbulent state (`zonostrophic instability') which occur…
A barotropic model of eddy saturation
Navid C. Constantinou
"Eddy saturation" refers to a regime in which the total volume transport of an oceanic current is insensitive to the wind stress strength. Baroclinicity is currently believed to be…
Beta-plane turbulence above monoscale topography
Navid C. Constantinou, William R. Young
Using a one-layer QG model, we study the effect of random monoscale topography on forced beta-plane turbulence. The forcing is a uniform steady wind stress that produces both a uni…
A statistical state dynamics-based study of the structure and mechanism of large-scale motions in plane Poiseuille flow
Brian F. Farrell, Petros J. Ioannou, Javier Jiménez +3
The perspective of statistical state dynamics (SSD) has recently been applied to the study of mechanisms underlying turbulence in various physical systems. An example implementatio…
Statistical state dynamics of jet/wave coexistence in barotropic beta-plane turbulence
Navid C. Constantinou, Brian F. Farrell, Petros J. Ioannou
Jets coexist with planetary scale waves in the turbulence of planetary atmospheres. The coherent component of these structures arises from cooperative interaction between the coher…
Formation of large-scale structures by turbulence in rotating planets
Navid C. Constantinou
This thesis presents a newly developed theory for the formation and maintenance of eddy-driven jets in planetary turbulence. The novelty is that jet formation and maintenance is st…
S3T stability of the homogeneous state of barotropic beta-plane turbulence
Nikolaos A. Bakas, Navid C. Constantinou, Petros J. Ioannou
Zonal jets and non-zonal large-scale flows are often present in forced-dissipative barotropic turbulence on a beta-plane. The dynamics underlying the formation of both zonal and no…