Search Results

You are looking at 1 - 10 of 12 items for :

  • In Honor of Bach-Lien Hua: Ocean Scale Interactions x
  • All content x
Clear All
Audrey Delpech, Claire Ménesguen, Yves Morel, Leif N. Thomas, Frédéric Marin, Sophie Cravatte, and Sylvie Le Gentil

transferring energy to the deep ocean. Fig . 1. Wavenumber frequency diagram with the dispersion relations for equatorial Kelvin waves (green), Yanai waves (red), and baroclinic Rossby waves (blue). Only the first baroclinic mode is represented. The dispersion relation for barotropic Rossby waves with different meridional wavenumbers (0, 1 × 10 −6 , 2 × 10 −6 , and 4 × 10 −6 m −1 from top to bottom) are in black. The frequency and wavenumbers of the forcing used in the experiments conducted in this study

Restricted access
Sandy Grégorio, Thierry Penduff, Guillaume Sérazin, Jean-Marc Molines, Bernard Barnier, and Joël Hirschi

another aspect of the interannual-to-decadal variability of the AMOC computed along geopotential levels. Both studies revealed that when mesoscale eddies are (even partially) resolved, nonlinearities become significant and the phase of the AMOC time series is no longer locked to the phase of the atmospheric forcing: it becomes partly chaotic, up to decadal time scales. Using a laminar global OGCM with an increase in resolution in the Agulhas region driven by an atmospheric reanalysis, Biastoch et al

Full access
François Ascani, Eric Firing, Julian P. McCreary, Peter Brandt, and Richard J. Greatbatch

the EDJs as basin modes does not appear to be essential to the theory. EIC-like currents also appear but only within a few degrees from the western boundary, inconsistent with the Atlantic observations. To remedy this discrepancy, Ménesguen et al. (2009) explore the case where the forcing is still along the western boundary but is now confined to the upper 2500 m—instead of appearing as a single baroclinic mode. In this case, the forcing excites not only the short low baroclinic mode MRG waves

Full access
A. M. Treguier, C. Lique, J. Deshayes, and J. M. Molines

are distributed on the same ¼° grid. We also use a numerical simulation performed in the framework of the Drakkar project ( Barnier et al. 2014 ) with the ORCA12 model. It is based on the NEMO modeling framework ( Madec 2008 ) for the ocean and sea ice. The isotropic tripolar grid covers the global ocean with a resolution of 1/12° (9.3 km) at the equator, refined at higher latitudes (6.5 km at 45°, 1.8 km in the Ross and Weddell seas). The atmospheric forcing, the Drakkar forcing set (DFS4.4), is

Full access
Thomas Meunier, Enric Pallàs Sanz, Miguel Tenreiro, José Ochoa, Angel Ruiz Angulo, and Christian Buckingham

link between layering and mixing is within reach, making such links for the case of LCEs might be a more challenging prospect. Warm-core rings are, in general, near-surface ventilated eddies ( Dewar 1987 , 1988 ), and atmospheric forcing in the Gulf of Mexico is particularly intense, including hurricanes and cold fronts. These latter processes result in pronounced momentum and heat fluxes that mix and cool the ocean as well as generate inertia gravity waves (IGWs) that penetrate deep into the

Full access
Nils Brüggemann and Carsten Eden

. This permanent source of available potential energy (APE) parameterizes forcing in the ocean acting on large scales and balances the conversion of available potential energy into kinetic energy by baroclinic production. The kinetic energy injected by baroclinic production has to be balanced by some kind of dissipation and we apply two different kinds of kinetic energy dissipation. Momentum dissipation by a linear drag of the zonal-mean velocity field acts predominantly on the largest scales. This

Full access
Alain Colin de Verdière and Michel Ollitrault

et al. (1993) , the barotropic streamfunction is obtained by integrating along potential vorticity contours the two forcings: the Ekman pumping and the baroclinic contribution to bottom pressure torque [the so-called JEBAR effect found by Sarkisyan and Ivanov (1971) ]. (v) Quite a number of other studies used full blown OGCMs to spin up the barotropic circulation keeping the model temperature and salinity close to the observed time-mean temperature and salinity ( Sarkisyan and Keonjiyan 1975

Full access
C. Ménesguen, S. Le Gentil, P. Marchesiello, and N. Ducousso

basin using a pseudospectral NHB model on a cubic domain [(4500 m) 3 , up to 2048 3 grid points]. Their grid aspect ratio dx / dz is set to 1 in order to properly represent nonhydrostatic dynamics. They highlight a forward energy cascade generated by a stochastic forcing at scales smaller than the forcing scale (around 450 m in their oceanic application). Pouquet and Marino (2013) show an increase of the forward cascade with higher Rossby and Reynolds numbers, while Marino et al. (2015) show

Full access
A. C. Barbosa Aguiar, C. Ménesguen, S. Le Gentil, R. Schopp, and X. Carton

momentum and density are equal (Prandtl number is 1), suppressing McIntyre’s instability ( McIntyre 1970 ). The time integration follows a leapfrog scheme with the Matsuno scheme blended every five time steps. The baroclinic time step is 20 s. No explicit forcing is applied. The initial vortex profile is a solution of the QG dynamics and therefore will be weakly unstable in the PE framework. Small random perturbations are initially added to the energy of the system in order to accelerate the slow

Full access
Yang Jiao and W. K. Dewar

of the topic are given by Ferrari and Wunsch (2010 , 2009) and Wunsch and Ferrari (2004) . They argue that 0.4 TW (1 TW = 10 12 W; Munk and Wunsch 1998 ; St. Laurent and Simmons 2006 ) is supplied to the potential energy field of the ocean in order to sustain the observed stratification and that this energetic requirement can be approximately accounted for by the winds and the tides. Hughes et al. (2009) argue that buoyant forcing also plays an important role. The sequence leading to

Full access