• Alford, M. H., 2010: Sustained, full-water-column observations of internal waves and mixing near Mendocino Escarpment. J. Phys. Oceanogr., 40, 26432660, doi:10.1175/2010JPO4502.1.

    • Search Google Scholar
    • Export Citation
  • Alford, M. H., and M. C. Gregg, 2001: Near-inertial mixing: Modulation of shear, strain and microstructure at low latitude. J. Geophys. Res., 106, 16 94716 968, doi:10.1029/2000JC000370.

    • Search Google Scholar
    • Export Citation
  • Alford, M. H., M. F. Cronin, and J. M. Klymak, 2012: Annual cycle and depth penetration of wind-generated near-inertial internal waves at Ocean Station Papa in the northeast Pacific. J. Phys. Oceanogr., 42, 889909, doi:10.1175/JPO-D-11-092.1.

    • Search Google Scholar
    • Export Citation
  • Cairns, J. L., and G. O. Williams, 1976: Internal wave observations from a midwater float, 2. J. Geophys. Res., 81, 19431950, doi:10.1029/JC081i012p01943.

    • Search Google Scholar
    • Export Citation
  • Comiso, J. C., 2012: Large decadal decline of the Arctic multiyear ice cover. J. Climate, 25, 11761193, doi:10.1175/JCLI-D-11-00113.1.

    • Search Google Scholar
    • Export Citation
  • D’Asaro, E. A., and H. Perkins, 1984: A near-inertial internal wave spectrum for the Sargasso Sea in late summer. J. Phys. Oceanogr., 14, 489505, doi:10.1175/1520-0485(1984)014<0489:ANIIWS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • D’Asaro, E. A., and M. D. Morehead, 1991: Internal waves and velocity fine structure in the Arctic Ocean. J. Geophys. Res.,96, 12 725–12 738, doi:10.1029/91JC01071.

  • D’Asaro, E. A., and J. H. Morison, 1992: Internal waves and mixing in the Arctic Ocean. Deep-Sea Res.,39, S459–S484, doi:10.1016/S0198-0149(06)80016-6.

  • D’Asaro, E. A., C. C. Eriksen, M. D. Levine, P. Niiler, C. A. Paulson, and P. Vanmeurs, 1995: Upper-ocean inertial currents forced by a strong storm. Part I: Data and comparisons with linear theory. J. Phys. Oceanogr., 25, 29092936, doi:10.1175/1520-0485(1995)025<2909:UOICFB>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Emery, W. J., and R. E. Thomson, 2004: Data Analysis Methods in Physical Oceanography. 2nd ed. Elsevier, 638 pp.

  • Fer, I., 2009: Weak vertical diffusion allows maintenance of cold halocline in the central Arctic. Atmos. Oceanic Sci. Lett., 2, 148152.

    • Search Google Scholar
    • Export Citation
  • Fer, I., R. Skogseth, and F. Geyer, 2010: Internal waves and mixing in the marginal ice zone near the Yermak Plateau. J. Phys. Oceanogr., 40, 16131630, doi:10.1175/2010JPO4371.1.

    • Search Google Scholar
    • Export Citation
  • Furuichi, N., T. Hibiya, and Y. Niwa, 2008: Model-predicted distribution of wind-induced internal wave energy in the world’s oceans. J. Geophys. Res., 113, C09034, doi:10.1029/2008JC004768.

    • Search Google Scholar
    • Export Citation
  • Garrett, C. J., and W. H. Munk, 1975: Space-time scales of internal waves: A progress report. J. Geophys. Res., 80, 291297, doi:10.1029/JC080i003p00291.

    • Search Google Scholar
    • Export Citation
  • Gregg, M. C., E. A. D’Asaro, T. J. Shay, and N. Larson, 1986: Observations of persistent mixing and near-inertial internal waves. J. Phys. Oceanogr., 16, 856884, doi:10.1175/1520-0485(1986)016<0856:OOPMAN>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Guthrie, J., J. H. Morison, and I. Fer, 2013: Revisiting internal waves and mixing in the Arctic Ocean. J. Geophys. Res., 118, 3966–3977, doi:10.1002/jgrc.20294.

    • Search Google Scholar
    • Export Citation
  • Halle, C., and R. Pinkel, 2003: Internal wave variability in the Beaufort Sea during the winter of 1993/1994. J. Geophys. Res., 108, 3210, doi:10.1029/2000JC000703.

    • Search Google Scholar
    • Export Citation
  • Kwok, R., and D. A. Rothrock, 2009: Decline in Arctic sea ice thickness from submarine and ICESat records: 1958–2008. Geophys. Res. Lett., 36, L15501, doi:10.1029/2009GL039035.

    • Search Google Scholar
    • Export Citation
  • Leaman, K. D., and T. B. Sanford, 1975: Vertical energy propagation of inertial waves: A vector spectral analysis of velocity profiles. J. Geophys. Res., 80, 19751978, doi:10.1029/JC080i015p01975.

    • Search Google Scholar
    • Export Citation
  • Lee, D.-K., and P. P. Niiler, 1998: The inertial chimney: The near-inertial energy drainage from the ocean surface to the deep layer. J. Geophys. Res., 103, 75797591, doi:10.1029/97JC03200.

    • Search Google Scholar
    • Export Citation
  • Levine, M. D., C. A. Paulson, and J. H. Morison, 1985: Internal waves in the Arctic Ocean: Comparison with lower-latitude observations. J. Phys. Oceanogr., 15, 800809, doi:10.1175/1520-0485(1985)015<0800:IWITAO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Levine, M. D., A. P. Clayton, and J. H. Morison, 1987: Observations of internal gravity waves under the Arctic pack ice. J. Geophys. Res., 92, 779782, doi:10.1029/JC092iC01p00779.

    • Search Google Scholar
    • Export Citation
  • McPhee, M. G., 2008: Air-Ice-Ocean Interaction: Turbulent Ocean Boundary Layer Exchange Processes. Springer, 215 pp.

  • McPhee, M. G., T. Kikuchi, J. H. Morison, and T. P. Stanton, 2003: Ocean-to-ice heat flux at the North Pole environmental observatory. Geophys. Res. Lett., 30, 2274, doi:10.1029/2003GL018580.

    • Search Google Scholar
    • Export Citation
  • Merrifield, M. A., and R. Pinkel, 1996: Inertial currents in the Beaufort Sea: Observations of response to wind and shear. J. Geophys. Res., 101, 65776590, doi:10.1029/95JC03625.

    • Search Google Scholar
    • Export Citation
  • Morison, J. H., C. E. Long, and M. D. Levine, 1985: Internal wave dissipation under sea ice. J. Geophys. Res., 90, 11 95911 966, doi:10.1029/JC090iC06p11959.

    • Search Google Scholar
    • Export Citation
  • Osborn, T. R., 1980: Estimates of the local rate of vertical diffusion from dissipation measurements. J. Phys. Oceanogr., 10, 8389, doi:10.1175/1520-0485(1980)010<0083:EOTLRO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Pinkel, R., 1984: Doppler sonar observations of internal waves: The wavenumber-frequency spectrum. J. Phys. Oceanogr., 14, 12491270, doi:10.1175/1520-0485(1984)014<1249:DSOOIW>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Pinkel, R., 2005: Near-inertial wave propagation in the western Arctic. J. Phys. Oceanogr., 35, 645665, doi:10.1175/JPO2715.1.

  • Pinkel, R., 2008: The wavenumber–frequency spectrum of vortical and internal-wave shear in the western Arctic Ocean. J. Phys. Oceanogr., 38, 277290, doi:10.1175/2006JPO3558.1.

    • Search Google Scholar
    • Export Citation
  • Plueddemann, A. J., R. Krishfield, T. Takizawa, K. Hatakeyama, and S. Honjo, 1998: Upper ocean velocities in the Beaufort Gyre. Geophys. Res. Lett., 25, 183186, doi:10.1029/97GL53638.

    • Search Google Scholar
    • Export Citation
  • Polzin, K., E. Kunze, J. Hummon, and E. Firing, 2002: The finescale response of lowered ADCP velocity profiles. J. Atmos. Oceanic Technol., 19, 205224, doi:10.1175/1520-0426(2002)019<0205:TFROLA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Rainville, L., and R. A. Woodgate, 2009: Observations of internal wave generation in the seasonally ice-free Arctic. Geophys. Res. Lett., 36, L23604, doi:10.1029/2009GL041291.

    • Search Google Scholar
    • Export Citation
  • Sanford, T. B., E. A. D’Asaro, E. Kunze, J. H. Dunlap, R. G. Drever, M. A. Kennelly, M. D. Prater, and M. S. Horgan, 1993: An XCP user’s guide and reference manual. Applied Physics Laboratory Tech. Rep. APL-UW TR9309, 120 pp.

  • Sirevaag, A., and I. Fer, 2012: Vertical heat transfer in the Arctic Ocean: The role of double-diffusive mixing. J. Geophys. Res., 117, C07010, doi:10.1029/2012JC007910.

    • Search Google Scholar
    • Export Citation
  • Stroeve, J. C., V. Kattsov, A. Barrett, M. Serreze, T. Pavlova, M. Holland, and W. N. Meier, 2012: Trends in Arctic sea ice extent from CMIP5, CMIP3 and observations. Geophys. Res. Lett., 39, L16502, doi:10.1029/2012GL052676.

    • Search Google Scholar
    • Export Citation
  • Turner, J. S., 2010: The melting of ice in the Arctic Ocean: The influence of double-diffusive transport of heat from below. J. Phys. Oceanogr., 40, 249256, doi:10.1175/2009JPO4279.1.

    • Search Google Scholar
    • Export Citation
  • Yamazaki, H., and T. Osborn, 1990: Dissipation estimates for stratified turbulence. J. Geophys. Res., 95, 97399744, doi:10.1029/JC095iC06p09739.

    • Search Google Scholar
    • Export Citation
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Near-Inertial Mixing in the Central Arctic Ocean

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  • 1 Geophysical Institute, University of Bergen, Bergen, Norway
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Abstract

Observations were made in April 2007 of horizontal currents, hydrography, and shear microstructure in the upper 500 m from a drifting ice camp in the central Arctic Ocean. An approximately 4-day-long time series, collected about 10 days after a storm event, shows enhanced near-inertial oscillations in the first half of the measurement period with comparable upward- and downward-propagating energy. Rough estimates of wind work and near-inertial flux imply that the waves were likely generated by the previous storm. The near-inertial frequency band is associated with dominant clockwise rotation in time of the horizontal currents and enhanced dissipation rates of turbulent kinetic energy. The vertical profile of dissipation rate shows elevated values in the pycnocline between the relatively turbulent underice boundary layer and the deeper quiescent water column. Dissipation averaged in the pycnocline is near-inertially modulated, and its magnitude decays approximately at a rate implied by the reduction of energy over time. Observations suggest that near-inertial energy and internal wave–induced mixing play a significant role in vertical mixing in the Arctic Ocean.

Corresponding author address: Ilker Fer, Geophysical Institute, University of Bergen, Allégaten 70, 5007 Bergen, Norway. E-mail: ilker.fer@gfi.uib.no

Abstract

Observations were made in April 2007 of horizontal currents, hydrography, and shear microstructure in the upper 500 m from a drifting ice camp in the central Arctic Ocean. An approximately 4-day-long time series, collected about 10 days after a storm event, shows enhanced near-inertial oscillations in the first half of the measurement period with comparable upward- and downward-propagating energy. Rough estimates of wind work and near-inertial flux imply that the waves were likely generated by the previous storm. The near-inertial frequency band is associated with dominant clockwise rotation in time of the horizontal currents and enhanced dissipation rates of turbulent kinetic energy. The vertical profile of dissipation rate shows elevated values in the pycnocline between the relatively turbulent underice boundary layer and the deeper quiescent water column. Dissipation averaged in the pycnocline is near-inertially modulated, and its magnitude decays approximately at a rate implied by the reduction of energy over time. Observations suggest that near-inertial energy and internal wave–induced mixing play a significant role in vertical mixing in the Arctic Ocean.

Corresponding author address: Ilker Fer, Geophysical Institute, University of Bergen, Allégaten 70, 5007 Bergen, Norway. E-mail: ilker.fer@gfi.uib.no
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