Vertical velocity in the interaction between inertia‐gravity waves and submesoscale baroclinic vortical structures

[1] The interaction between submesoscale baroclinic vortical structures and large amplitude inertia-gravity waves (IGWs), with emphasis on the vertical velocity, is numerically investigated using a high-resolution three-dimensional non-hydrostatic model. A rich variety of vortex-wave interactions are possible depending on the potential vorticity (PV) content and length scale of the submesoscale monopoles or dipoles, and on the amplitude and wave number of the IGWs. On the one hand, large amplitude IGWs cause horizontal and vertical advection of the vortices, which conserve their stability though their geometry is largely modified by the wave motion. On the other hand, the horizontal vortical motion Doppler shifts the local frequency of IGWs. The vortical angular velocity and vortex density stratification lead to a wave dispersion relation involving the effective Coriolis frequency (Coriolis frequency plus the vortical angular velocity) and the total Brunt-Vaisala frequency. This inhomogeneous change in the local wave frequency causes IGWs to depart from their initial plane geometry. In the particular case of inertial waves, the nonlinear vortex-wave interaction generates spiral IGWs, having vertical velocities one order of magnitude larger than the submesoscale vortical flow in the absence of waves.

[1]  Eric Danioux,et al.  Propagation of Wind Energy into the Deep Ocean through a Fully Turbulent Mesoscale Eddy Field , 2008 .

[2]  P. Klein,et al.  A Resonance Mechanism Leading to Wind-Forced Motions with a 2f Frequency , 2008 .

[3]  A. Mahadevan,et al.  Submesoscale processes and dynamics, In: Ocean Modeling in an Eddying, Regime (AGU Monograph), M. Hecht and H. Hasumi (Eds.) , 2008 .

[4]  J. McWilliams,et al.  Mesoscale to Submesoscale Transition in the California Current System. Part I: Flow Structure, Eddy Flux, and Observational Tests , 2008 .

[5]  A. Viudez,et al.  Three-Dimensional Mesoscale Dipole Frontal Collisions , 2007 .

[6]  E. Pallàs‐Sanz,et al.  Three-dimensional ageostrophic motion in mesoscale vortex dipoles , 2007 .

[7]  I. Skjelvan,et al.  A submesoscale coherent eddy in the Greenland Sea in 2003 , 2006 .

[8]  A. Mahadevan.  Modeling vertical motion at ocean fronts: Are nonhydrostatic effects relevant at submesoscales? , 2006 .

[9]  I. Yavneh,et al.  Baroclinic Instability and Loss of Balance , 2005 .

[10]  M. McIntyre,et al.  Wave capture and wave–vortex duality , 2005, Journal of Fluid Mechanics.

[11]  A. Viudez,et al.  Optimal potential vorticity balance of geophysical flows , 2004, Journal of Fluid Mechanics.

[12]  E. D’Asaro,et al.  Meso- and Submesoscale Structure of a Convecting Field , 2004 .

[13]  P. E. An,et al.  Submesoscale Coastal Ocean Flows Detected by Very High Frequency Radar and Autonomous Underwater Vehicles , 2003 .

[14]  David G. Dritschel,et al.  A balanced approach to modelling rotating stably stratified geophysical flows , 2003, Journal of Fluid Mechanics.

[15]  A. Viudez,et al.  Vertical velocity in mesoscale geophysical flows , 2003, Journal of Fluid Mechanics.

[16]  Joseph Pedlosky,et al.  Waves In The Ocean And Atmosphere , 2003 .

[17]  P. Testor,et al.  Large-Scale Spreading of Deep Waters in the Western Mediterranean Sea by Submesoscale Coherent Eddies , 2003 .

[18]  A. Watson,et al.  Long-lived vortices as a mode of deep ventilation in the Greenland Sea , 2002, Nature.

[19]  Patrice Klein,et al.  Impact of sub-mesoscale physics on production and subduction of phytoplankton in an oligotrophic regime , 2001 .

[20]  Yz Miropol’sky,et al.  Dynamics of Internal Gravity Waves in the Ocean , 2001 .

[21]  O. Shishkina,et al.  Basic Sources of Internal Waves Generation in the Ocean , 2001 .

[22]  T. Hibiya,et al.  Response of the deep ocean internal wave field to traveling midlatitude storms as observed in long-term current measurements , 1999 .

[23]  P. V. Meurs,et al.  Interactions between Near-Inertial Mixed Layer Currents and the Mesoscale: The Importance of Spatial Variabilities in the Vorticity Field* , 1998 .

[24]  W. Young,et al.  Propagation of near-inertial oscillations through a geostrophic flow , 1997 .

[25]  D. Rudnick,et al.  Intensive surveys of the Azores Front 1. Tracers and dynamics , 1996 .

[26]  G. O. Roberts,et al.  Scattering of Inertial waves by an Ocean Front , 1986 .

[27]  E. Kunze.  Near-Inertial Wave Propagation In Geostrophic Shear , 1985 .

[28]  James C. McWilliams,et al.  Submesoscale, coherent vortices in the ocean , 1985 .

[29]  E. Kunze,et al.  Observations of Near-Inertial Waves in a Front , 1984 .

[30]  R. Weller.  The Relation of Near-Inertial Motions Observed in the Mixed layer During the JASIN (1978) Experiment to the Local Wind Stress and to the Quasi-Geostrophic Flow Field , 1982 .

[31]  B. Hoskins,et al.  A new look at the ?-equation , 1978 .

[32]  B. Hoskins,et al.  A new look at the w-equation , 1978 .

[33]  H. Perkins.  Observed effect of an eddy on inertial oscillations , 1976 .

[34]  C. Mooers.  Several effects of a baroclinic current on the cross-stream propagation of inertial-internal waves , 1975 .

[35]  C. Mooers.  Several effects of baroclinic currents on the three‐dimensional propagation of inertial‐internal waves† , 1975 .

[36]  Owen S. Lee,et al.  INTERNAL WAVES IN THE OCEAN , 1962 .