• Clarke, R., and G. Hess, 1974: Geostrophic departure and the functions A and B of Rossby-number similarity theory. Bound.-Layer Meteor., 7, 267287, doi:10.1007/BF00240832.

    • Search Google Scholar
    • Export Citation
  • Cole, S., M. Timmermans, J. Toole, R. Krishfield, and F. Thwaites, 2014: Ekman veering, internal waves, and turbulence observed under Arctic sea ice. J. Phys. Oceanogr., 44, 13061328, doi:10.1175/JPO-D-12-0191.1.

    • 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
  • Du Vachat, R., and L. Musson-Genon, 1982: Rossby similarity and turbulent formulations. Bound.-Layer Meteor., 23, 4768, doi:10.1007/BF00116111.

    • Search Google Scholar
    • Export Citation
  • Ekman, V. W., 1905: On the influence of the earth’s rotation on ocean-currents. Ark. Mat., Astron. Fys.,2, 1–52.

  • Fer, I., 2006: Scaling turbulent dissipation in an Arctic fjord. Deep-Sea Res. II, 53, 7795, doi:10.1016/j.dsr2.2006.01.003.

  • Fofonoff, N. P., and R. C. Millard Jr., 1983: Algorithms for computation of fundamental properties of seawater. UNESCO Tech. Paper in Marine Science 44, 58 pp. [Available online at http://unesdoc.unesco.org/images/0005/000598/059832eb.pdf.]

  • Grachev, A., C. Fairall, P. Persson, E. Andreas, and P. Guest, 2005: Stable boundary-layer scaling regimes: The SHEBA data. Bound.-Layer Meteor., 116, 201235, doi:10.1007/s10546-004-2729-0.

    • Search Google Scholar
    • Export Citation
  • Grachev, A., E. Andreas, C. Fairall, P. Guest, and P. G. Persson, 2013: The critical Richardson number and limits of applicability of local similarity theory in the stable boundary layer. Bound.-Layer Meteor., 147, 5182, doi:10.1007/s10546-012-9771-0.

    • Search Google Scholar
    • Export Citation
  • Hakkinen, S., A. Proshutinsky, and I. Ashik, 2008: Sea ice drift in the Arctic since the 1950s. Geophys. Res. Lett., 35, L19704, doi:10.1029/2008GL034791.

    • Search Google Scholar
    • Export Citation
  • Holland, M. M., 2003: An improved single-column model representation of ocean mixing associated with summertime leads: Results from a SHEBA case study. J. Geophys. Res., 108, 3107, doi:10.1029/2002JC001557.

    • Search Google Scholar
    • Export Citation
  • Hudson, S. R., M. A. Granskog, A. Sundfjord, A. Randelhoff, A. H. H. Renner, and D. V. Divine, 2013: Energy budget of first-year Arctic sea ice in advanced stages of melt. Geophys. Res. Lett., 40, 26792683, doi:10.1002/grl.50517.

    • Search Google Scholar
    • Export Citation
  • Kwok, R., G. Spreen, and S. Pang, 2013: Arctic sea ice circulation and drift speed: Decadal trends and ocean currents. J. Geophys. Res., 118, 24082425, doi:10.1002/jgrc.20191.

    • Search Google Scholar
    • Export Citation
  • Leppäranta, M., 2011: The Drift of Sea Ice. Springer, 347 pp., doi:10.1007/978-3-642-04683-4.

  • Lu, P., Z. Li, B. Cheng, and M. Leppranta, 2011: A parameterization of the ice-ocean drag coefficient. J. Geophys. Res., 116, C07019, doi:10.1029/2010JC006878.

    • Search Google Scholar
    • Export Citation
  • Maslanik, J. A., C. Fowler, J. Stroeve, S. Drobot, J. Zwally, D. Yi, and W. Emery, 2007: A younger, thinner Arctic ice cover: Increased potential for rapid, extensive sea-ice loss. Geophys. Res. Lett., 34, L24501, doi:10.1029/2007GL032043.

    • Search Google Scholar
    • Export Citation
  • McPhee, M. G., 1978: A simulation of inertial oscillation in drifting pack ice. Dyn. Atmos. Oceans, 2, 107122, doi:10.1016/0377-0265(78)90005-2.

    • Search Google Scholar
    • Export Citation
  • McPhee, M. G., 1979: The effect of the oceanic boundary layer on the mean drift of pack ice: Application of a simple model. J. Phys. Oceanogr., 9, 388400, doi:10.1175/1520-0485(1979)009<0388:TEOTOB>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • McPhee, M. G., 1981: An analytic similarity theory for the planetary boundary layer stabilized by surface buoyancy. Bound.-Layer Meteor., 21, 325339, doi:10.1007/BF00119277.

    • Search Google Scholar
    • Export Citation
  • McPhee, M. G., 1982: Sea ice drag laws and simple boundary layer concepts, including application to rapid melting. U.S. Army Cold Regions Research and Engineering Laboratory Tech. Rep., 25 pp.

  • McPhee, M. G., 1992: Turbulent heat flux in the upper ocean under sea ice. J. Geophys. Res., 97, 53655379, doi:10.1029/92JC00239.

  • McPhee, M. G., 2008: Air-Ice-Ocean Interaction: Turbulent Ocean Boundary Layer Exchange Processes. Springer, 215 pp., doi:10.1007/978-0-387-78335-2.

  • McPhee, M. G., 2012: Advances in understanding ice–ocean stress during and since AIDJEX. Cold Reg. Sci. Technol., 76–77, 2436, doi:10.1016/j.coldregions.2011.05.001.

    • Search Google Scholar
    • Export Citation
  • McPhee, M. G., and L. H. Kantha, 1989: Generation of internal waves by sea ice. J. Geophys. Res., 94, 32873302, doi:10.1029/JC094iC03p03287.

    • Search Google Scholar
    • Export Citation
  • McPhee, M. G., G. A. Maykut, and J. H. Morison, 1987: Dynamics and thermodynamics of the ice/upper ocean system in the marginal ice zone of the Greenland Sea. J. Geophys. Res., 92, 70177031, doi:10.1029/JC092iC07p07017.

    • Search Google Scholar
    • Export Citation
  • Morison, J. H., and M. G. McPhee, 2001: Ice–ocean interaction. Encyclopedia of Ocean Sciences, Academic Press, 1271–1281, doi:10.1006/rwos.2001.0003.

  • Morison, J. H., M. G. McPhee, and G. A. Maykut, 1987: Boundary layer, upper ocean, and ice observations in the Greenland Sea marginal ice zone. J. Geophys. Res., 92, 69877011, doi:10.1029/JC092iC07p06987.

    • Search Google Scholar
    • Export Citation
  • Notz, D., M. G. McPhee, M. G. Worster, G. A. Maykut, K. H. Schlünzen, and H. Eicken, 2003: Impact of underwater-ice evolution on Arctic summer sea ice. J. Geophys. Res., 108, 3223, doi:10.1029/2001JC001173.

    • Search Google Scholar
    • Export Citation
  • Olbers, D., J. Willebrand, and C. Eden, 2012: Ocean Dynamics. Springer, 708 pp., doi:10.1007/978-3-642-23450-7.

  • Padman, L., and S. Erofeeva, 2004: A barotropic inverse tidal model for the Arctic Ocean. Geophys. Res. Lett., 31, L02303, doi:10.1029/2003GL019003.

    • Search Google Scholar
    • Export Citation
  • Prandke, H., and A. Stips, 1998: Test measurements with an operational microstructure-turbulence profiler: Detection limit of dissipation rates. Aquat. Sci., 60, 191209, doi:10.1007/s000270050036.

    • Search Google Scholar
    • Export Citation
  • Renner, A. H., S. Hendricks, S. Gerland, J. Beckers, C. Haas, and T. Krumpen, 2013: Large-scale ice thickness distribution of first-year sea ice in spring and summer north of Svalbard. Ann. Glaciol., 54, 1318, doi:10.3189/2013AoG62A146.

    • Search Google Scholar
    • Export Citation
  • Rossby, C.-G., and R. B. Montgomery, 1935: The Layer of Frictional Influence in Wind and Ocean Currents. Papers in Physical Oceanography and Meteorology, Vol. 3, Woods Hole Oceanographic Institute, 101 pp., doi:10.1575/1912/1157.

  • Sakshaug, E., 2004: Primary and secondary production in the Arctic seas. The Organic Carbon Cycle in the Arctic Ocean, R. Stein and R. MacDonald, Eds., Springer, 57–81, doi:10.1007/978-3-642-18912-8_3.

  • Schmidt, G. A., C. M. Bitz, U. Mikolajewicz, and L.-B. Tremblay, 2004: Ice–ocean boundary conditions for coupled models. Ocean Modell., 7, 5974, doi:10.1016/S1463-5003(03)00030-1.

    • Search Google Scholar
    • Export Citation
  • Shaw, W. J., T. P. Stanton, M. G. McPhee, and T. Kikuchi, 2008: Estimates of surface roughness length in heterogeneous under-ice boundary layers. J. Geophys. Res., 113, C08030, doi:10.1029/2007JC004550.

    • Search Google Scholar
    • Export Citation
  • Sirevaag, A., 2009: Turbulent exchange coefficients for the ice/ocean interface in case of rapid melting. Geophys. Res. Lett., 36, L04606, doi:10.1029/2008GL036587.

    • Search Google Scholar
    • Export Citation
  • Sirevaag, A., M. G. McPhee, J. H. Morison, W. J. Shaw, and T. P. Stanton, 2010: Wintertime mixed layer measurements at Maud Rise, Weddell Sea. J. Geophys. Res., 115, C02009, doi:10.1029/2008JC005141.

    • Search Google Scholar
    • Export Citation
  • Skyllingstad, E. D., C. A. Paulson, W. S. Pegau, M. G. McPhee, and T. Stanton, 2003: Effects of keels on ice bottom turbulence exchange. J. Geophys. Res., 108, 3372, doi:10.1029/2002JC001488.

    • Search Google Scholar
    • Export Citation
  • Steele, M., J. H. Morison, and N. Untersteiner, 1989: The partition of air-ice-ocean momentum exchange as a function of ice concentration, floe size, and draft. J. Geophys. Res., 94, 12 73912 750, doi:10.1029/JC094iC09p12739.

    • Search Google Scholar
    • Export Citation
  • Timco, G., and R. Frederking, 1996: A review of sea ice density. Cold Reg. Sci. Technol., 24, 16, doi:10.1016/0165-232X(95)00007-X.

  • Toole, J. M., M.-L. Timmermans, D. K. Perovich, R. A. Krishfield, A. Proshutinsky, and J. A. Richter-Menge, 2010: Influences of the ocean surface mixed layer and thermohaline stratification on Arctic sea ice in the central Canada basin. J. Geophys. Res., 115, C10018, doi:10.1029/2009JC005660.

    • Search Google Scholar
    • Export Citation
  • Untersteiner, N., 1968: Natural desalination and equilibrium salinity profile of perennial sea ice. J. Geophys. Res., 73, 12511257, doi:10.1029/JB073i004p01251.

    • Search Google Scholar
    • Export Citation
  • Wadhams, P., and N. Toberg, 2012: Changing characteristics of Arctic pressure ridges. Polar Sci., 6, 7177, doi:10.1016/j.polar.2012.03.002.

    • Search Google Scholar
    • Export Citation
  • Yamazaki, H., and T. Osborn, 1990: Dissipation estimates for stratified turbulence. J. Geophys. Res.,95, 9739–9744, doi:10.1029/JC095iC06p09739.

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Effects of a Shallow Pycnocline and Surface Meltwater on Sea Ice–Ocean Drag and Turbulent Heat Flux

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  • 1 Norwegian Polar Institute, Tromsø, Norway
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Abstract

Comprehensive boundary layer measurements from a drift station on first-year ice in the late summer of 2012 in the Nansen basin, when stable stratification in the upper ocean extended all the way to the surface, are analyzed. Observed quadratic ice–ocean drag coefficients, based on measurements of wind stress, are roughly 3.6 × 10−3, consistent with neutral-stability Rossby similarity scaling. The turning angles of 32°–39° between surface velocity and stress are larger than Rossby similarity predicts and obey a different scaling. This can be explained by the shallow pycnocline forcing the Ekman transport into a thin layer and modeled roughly employing a simple first-order correction to Rossby similarity. Turbulent shear stress in the ice–ocean boundary layer is on average 3 times smaller than the estimate based on wind stress, possibly because internal wave drag was significant. This lowers vertical scalar fluxes by 38% compared to a scenario where turbulent stress accounts for the total drag. The authors measure an average upward ocean–ice heat flux of 10 W m−2, which is 50% smaller than predicted by a bulk heat flux parameterization. This reduction is attributed to additional sources of heat and freshwater that alter the ice–ocean interface salt balance. This study shows that a commonly used bulk heat flux parameterization is a special case of a simple downgradient parameterization allowing for a modified interface salt budget. For similar wind forcing, observed ice–ocean fluxes of heat and salt were 40%–100% larger when the ice-relative current approached from a nearby pressure ridge keel than otherwise.

Additional affiliation: University of Tromsø, Tromsø, Norway.

Corresponding author address: Achim Randelhoff, Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway. E-mail: achim@npolar.no

Abstract

Comprehensive boundary layer measurements from a drift station on first-year ice in the late summer of 2012 in the Nansen basin, when stable stratification in the upper ocean extended all the way to the surface, are analyzed. Observed quadratic ice–ocean drag coefficients, based on measurements of wind stress, are roughly 3.6 × 10−3, consistent with neutral-stability Rossby similarity scaling. The turning angles of 32°–39° between surface velocity and stress are larger than Rossby similarity predicts and obey a different scaling. This can be explained by the shallow pycnocline forcing the Ekman transport into a thin layer and modeled roughly employing a simple first-order correction to Rossby similarity. Turbulent shear stress in the ice–ocean boundary layer is on average 3 times smaller than the estimate based on wind stress, possibly because internal wave drag was significant. This lowers vertical scalar fluxes by 38% compared to a scenario where turbulent stress accounts for the total drag. The authors measure an average upward ocean–ice heat flux of 10 W m−2, which is 50% smaller than predicted by a bulk heat flux parameterization. This reduction is attributed to additional sources of heat and freshwater that alter the ice–ocean interface salt balance. This study shows that a commonly used bulk heat flux parameterization is a special case of a simple downgradient parameterization allowing for a modified interface salt budget. For similar wind forcing, observed ice–ocean fluxes of heat and salt were 40%–100% larger when the ice-relative current approached from a nearby pressure ridge keel than otherwise.

Additional affiliation: University of Tromsø, Tromsø, Norway.

Corresponding author address: Achim Randelhoff, Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway. E-mail: achim@npolar.no
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