Abstract
This paper analyzes variations of vertical velocity w simulated by the 1/10° Ocean General Circulation Model for the Earth Simulator (OFES). Strong w-variability is found in the deep oceans. When w is WKBJ-normalized, the standard deviation averaged over the Southern Ocean increases with depth and is larger than 8 × 10 − 3 cm/s throughout the water column below 1,500 m. Evidences are presented that link this w-variability to internal waves generated by quasi-steady currents over topography. The aliasing errors in lag-3-day correlations suggest a bottom generation of near-inertial waves. A scale analysis indicates that vertically propagating waves that can be resolved by the OFES model are waves with frequencies of the order of inertial frequency and wavelengths comparable to the order of the grid size. The vertical energy flux associated with these waves is substantial. When integrated globally, the vertical energy flux is upward in the upper 4 km and reaches maximum values of about 0.8 TW at about 1 to 2 km depth. Thus, the w-variability in the 1/10° OFES integration points not only to a strong bottom generation of near-inertial internal waves in the deep Southern Ocean but also to the possibility that the power provided by internal waves generated by non-tidal currents over topography can be comparable to the power provided by internal waves generated by tidal flows over topography.
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References
Althaus MH (2003) Energy available for ocean mixing redistributed by long-range propagation of internal waves. Nature 423:159–162
Bell TH (1975) Topographically generated internal waves in the open ocean. J Geophys Res 80:320–327
Egbert G, Ray RD (2000) Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data. Nature 405:775–778
Furuichi N, Hibiya T, Niwa Y (2008) Model-predicted distribution of wind-induced internal wave energy. J Geophys Res 113:C09034. doi:10.1029/2008JC004768
Garrett C, Munk W (1979) Internal waves in the ocean. Annu Rev Fluid Mech 11:339–369
Gill AE (1982) Atmosphere–ocean dynamics. Academic, New York
Klein P, Isern-Fontanet J, Lapeyre G, Roullet G, Danioux E, Chapron B, Le Bentil S, Sasaki H (2009) Diagnosis of vertical velocities in the upper ocean from high resolution sea surface height. Geophys Res Lett 36:L12603. doi:10.1029/2009GL038359
Komori N, Ohfuchi W, Taguchi B, Sasaki H, Klein P (2008) Deep ocean inertia-gravity waves simulated in a high-resolution global coupled atmosphere–ocean GCM. Geophys Res Lett 35:L04610. doi:10.1029/2007GL032807
Masumoto Y and coauthors (2004) A fifty-year eddy-resolving simulation of the world ocean—preliminary outcomes of OFES (OGCM for the Earth Simulator). J Earth Simul 1:35–56
Munk W (1981) Internal waves and small-scale processes. In: Warren BA, Wunsch C (eds) Evolution of physical oceanography: scientific surveys in honor of Henry Stommel. MIT, Cambridge, pp 264–291
Munk W, Wunsch C (1998) Abyssal recipes II: energetics of tidal & wind mixing. Deep-Sea Res I 45:1927–2010
Nash JD, Kunze E, Toole JM, Schmitt RW (2004) Internal tide reflection and turbulent mixing on the continental slope. J Phys Oceanogr 34:1117–1134
Pacanowski RC, Griffies SM (2000) MOM 3.0 manual. Geophysical Fluid Dynamics Laboratory/National Oceanic and Atmospheric Administration, Princeton, 680 pp
Sasai Y, Ishida A, Yamanaka Y, Sasaki H (2004) Chlorofluorocarbons in a global ocean eddy-resolving OGCM: pathway and formation of Antarctic Bottom Water. Geophys Res Lett 31(12):L12305. doi:10.1029/2004GL019895
Sasaki H, Sasai Y, Kawahara S, Furuichi M, Araki F, Ishida A, Yamanaka Y, Masumoto Y, Sakuma H (2004) A series of eddy-resolving ocean simulations in the world ocean: OFES (OGCM for the Earth Simulator) project, OCEAN’04, vol 3, pp 1535–1541. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?reload=true&isnumber=30473&arnumber=1406350&count=110&index=64
Sasaki H, Nonaka M, Masumoto Y, Sasai Y, Uehara H, Sakuma H (2008) An eddy-resolving hindcast simulation of the quasiglobal ocean from 1950 to 2003 on the Earth Simulator. In: Hamilton K, Ohfuchi W (ed) High resolution numerical modelling of the atmosphere and ocean. Springer, New York, pp 157–185
Schott F, Visbeck M, Fischer J (1993) Observations of vertical currents and convection in the central Greenland Sea during the winter of 1988–1989. J Geophys Res 98:14401–14421
von Storch J-S, Sasaki H, Marotzke J (2007) Wind-generated power input to the deep ocean: an estimate using a 1/10° general circulation model. J Phys Oceanogr 37:657–672
Wunsch C, Ferrari R (2004) Vertical mixing, energy, and the general circulation of the oceans. Annu Rev Fluid Mech 36:281–314
Wyrtki K (1981) An estimate of equatorial upwelling in the Pacific. J Phys Oceanogr 11:1205–1214
Acknowledgements
The author is grateful to Hideharu Sasaki for providing the OFES data. Thanks also to OFES project members. The OFES simulation was conducted on the Earth Simulator under the support of JAMSTEC. Thanks also to Zoltan Szuts for his comments regarding the WKBJ normalization.
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Responsible Editor: Yukio Masumoto
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von Storch, JS. Variations of vertical velocity in the deep oceans simulated by a 1/10° OGCM. Ocean Dynamics 60, 759–770 (2010). https://doi.org/10.1007/s10236-010-0303-5
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DOI: https://doi.org/10.1007/s10236-010-0303-5