• Allen, J. S., 1980: Models of wind-driven currents on the continental shelf. Annu. Rev. Fluid Mech., 12, 389433, doi:10.1146/annurev.fl.12.010180.002133.

    • Search Google Scholar
    • Export Citation
  • Barsugli, J. J., and D. S. Battisti, 1998: The basic effects of atmosphere–ocean thermal coupling on midlatitude variability. J. Atmos. Sci., 55, 477493, doi:10.1175/1520-0469(1998)055<0477:TBEOAO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Capet, X., P. Marchesiello, and J. McWilliams, 2004: Upwelling response to coastal wind profiles. Geophys. Res. Lett., 31, L13311, doi:10.1029/2004GL020123.

    • Search Google Scholar
    • Export Citation
  • Capet, X., F. Colas, J. McWilliams, P. Penven, and P. Marchesiello, 2008: Eddies in eastern-boundary subtropical upwelling systems. Ocean Modeling in an Eddying Regime, Meteor. Monogr., Vol. 177, Amer. Geophys. Union, 131–147, doi:10.1029/177GM10.

  • Chelton, D. B., M. G. Schlax, M. H. Freilich, and R. F. Milliff, 2004: Satellite measurements reveal persistent small-scale features in ocean winds. Science, 303, 978983, doi:10.1126/science.1091901.

    • Search Google Scholar
    • Export Citation
  • Chelton, D. B., M. G. Schlax, and R. M. Samelson, 2007: Summertime coupling between sea surface temperature and wind stress in the California Current System. J. Phys. Oceanogr., 37, 495517, doi:10.1175/JPO3025.1.

    • Search Google Scholar
    • Export Citation
  • Colas, F., J. C. McWilliams, X. Capet, and J. Kurian, 2012: Heat balance and eddies in the Peru–Chile Current system. Climate Dyn., 39, 509529, doi:10.1007/s00382-011-1170-6.

    • Search Google Scholar
    • Export Citation
  • Colas, F., X. Capet, J. C. McWilliams, and Z. Li, 2013: Mesoscale eddy buoyancy flux and eddy-induced circulation in eastern boundary currents. J. Phys. Oceanogr., 43, 10731095, doi:10.1175/JPO-D-11-0241.1.

    • Search Google Scholar
    • Export Citation
  • Davey, M. K., 1983: A two-level model of a thermally forced ocean basin. J. Phys. Oceanogr., 13, 169190, doi:10.1175/1520-0485(1983)013<0169:ATLMOA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Dorman, C. E., E. P. Dever, J. Largier, and D. Koračin, 2006: Buoy measured wind, wind stress and wind stress curl over the shelf off Bodega Bay, California. Deep-Sea Res. II, 53, 28502864, doi:10.1016/j.dsr2.2006.07.006.

    • Search Google Scholar
    • Export Citation
  • Edwards, K. A., and K. A. Kelly, 2007: Seasonal heat budget across the extent of the California Current. J. Phys. Oceanogr., 37, 518530, doi:10.1175/JPO2990.1.

    • Search Google Scholar
    • Export Citation
  • Fox-Kemper, B., R. Ferrari, and R. Hallberg, 2008: Parameterization of mixed layer eddies. Part I: Theory and diagnosis. J. Phys. Oceanogr., 38, 11451165, doi:10.1175/2007JPO3792.1.

    • Search Google Scholar
    • Export Citation
  • Frankignoul, C., A. Czaja, and B. L’Heveder, 1998: Air–sea feedback in the North Atlantic and surface boundary conditions for ocean models. J. Climate, 11, 23102324, doi:10.1175/1520-0442(1998)011<2310:ASFITN>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Holte, J., F. Straneo, J. T. Farrar, and R. A. Weller, 2014: Heat and salinity budgets at the stratus mooring in the southeast Pacific. J. Geophys. Res. Oceans, 119, 81628176, doi:10.1002/2014JC010256.

    • Search Google Scholar
    • Export Citation
  • Huang, R. X., and B. Qiu, 1994: Three-dimensional structure of the wind-driven circulation in the subtropical North Pacific. J. Phys. Oceanogr., 24, 16081622, doi:10.1175/1520-0485(1994)024<1608:TDSOTW>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Large, W. G., and S. Pond, 1981: Open ocean momentum flux measurements in moderate to strong winds. J. Phys. Oceanogr., 11, 324336, doi:10.1175/1520-0485(1981)011<0324:OOMFMI>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Large, W. G., and G. Danabasoglu, 2006: Attribution and impacts of upper-ocean biases in CCSM3. J. Climate, 19, 23252346, doi:10.1175/JCLI3740.1.

    • Search Google Scholar
    • Export Citation
  • Large, W. G., J. C. McWilliams, and S. C. Doney, 1994: Oceanic vertical mixing: A review and a model with a nonlocal boundary layer parameterization. Rev. Geophys., 32, 363403, doi:10.1029/94RG01872.

    • Search Google Scholar
    • Export Citation
  • Marchesiello, P., J. C. McWilliams, and A. Shchepetkin, 2003: Equilibrium structure and dynamics of the California Current system. J. Phys. Oceanogr., 33, 753783, doi:10.1175/1520-0485(2003)33<753:ESADOT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Marotzke, J., and D. W. Pierce, 1997: On spatial scales and lifetimes of SST anomalies beneath a diffusive atmosphere. J. Phys. Oceanogr., 27, 133139, doi:10.1175/1520-0485(1997)027<0133:OSSALO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Marshall, J., C. Hill, L. Perelman, and A. Adcroft, 1997: Hydrostatic, quasi-hydrostatic, and non-hydrostatic ocean modeling. J. Geophys. Res., 102, 57335752, doi:10.1029/96JC02776.

    • Search Google Scholar
    • Export Citation
  • McCreary, J. P., Y. Fukamachi, and P. K. Kundu, 1991: A numerical investigation of jets and eddies near an eastern ocean boundary. J. Geophys. Res., 96, 25152533, doi:10.1029/90JC02195.

    • Search Google Scholar
    • Export Citation
  • O’Neill, L. W., D. B. Chelton, S. K. Esbensen, and F. Wentz, 2005: High-resolution satellite measurements of the atmospheric boundary layer response to SST variations along the Agulhas return current. J. Climate, 18, 27062723, doi:10.1175/JCLI3415.1.

    • Search Google Scholar
    • Export Citation
  • Pedlosky, J., 1978: An inertial model of steady coastal upwelling. J. Phys. Oceanogr., 8, 171177, doi:10.1175/1520-0485(1978)008<0171:AIMOSC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Perlin, N., E. D. Skyllingstad, R. M. Samelson, and P. L. Barbour, 2007: Numerical simulation of air–sea coupling during coastal upwelling. J. Phys. Oceanogr., 37, 20812093, doi:10.1175/JPO3104.1.

    • Search Google Scholar
    • Export Citation
  • Renault, L., A. Hall, and J. C. McWilliams, 2016a: Orographic shaping of US West Coast wind profiles during the upwelling season. Climate Dyn., 46, 273289, doi:10.1007/s00382-015-2583-4.

    • Search Google Scholar
    • Export Citation
  • Renault, L., M. J. Molemaker, J. C. McWilliams, A. F. Shchepetkin, F. Lemarie, D. Chelton, S. Illig, and A. Hall, 2016b: Modulation of wind work by oceanic current interaction with the atmosphere. J. Phys. Oceanogr., 46, 16851704, doi:10.1175/JPO-D-15-0232.1.

    • Search Google Scholar
    • Export Citation
  • Richter, I., 2015: Climate model biases in the eastern tropical oceans: Causes, impacts and ways forward. Wiley Interdiscip. Res.: Climatic Change, 6, 345358, doi:10.1002/wcc.338.

    • Search Google Scholar
    • Export Citation
  • Roemmich, D., 1989: Mean transport of mass, heat, salt and nutrients in the southern California coastal waters: Implications for primary production and nutrient cycling. Deep-Sea Res., 36, 13591378, doi:10.1016/0198-0149(89)90088-5.

    • Search Google Scholar
    • Export Citation
  • Samelson, R. M., and R. A. de Szoeke, 1988: Semigeostrophic wind-driven thermocline upwelling at a coastal boundary. J. Phys. Oceanogr., 18, 13721383, doi:10.1175/1520-0485(1988)018<1372:SWDTUA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Seager, R., Y. Kushnir, and M. A. Cane, 1995: On heat flux boundary conditions for ocean models. J. Phys. Oceanogr., 25, 32193230, doi:10.1175/1520-0485(1995)025<3219:OHFBCF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Seo, H., A. J. Miller, and J. R. Norris, 2016: Eddy–wind interaction in the California Current System: Dynamics and impacts. J. Phys. Oceanogr., 46, 439459, doi:10.1175/JPO-D-15-0086.1.

    • Search Google Scholar
    • Export Citation
  • Spall, M. A., 2003: Islands in zonal flow. J. Phys. Oceanogr., 33, 26892701, doi:10.1175/1520-0485(2003)033<2689:IIZF>2.0.CO;2.

  • Stephens, G. L., G. G. Campbell, and T. H. Vonder Haar, 1981: Earth radiation budgets. J. Geophys. Res., 86, 97399760, doi:10.1029/JC086iC10p09739.

    • Search Google Scholar
    • Export Citation
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Coupled Ocean–Atmosphere Offshore Decay Scale of Cold SST Signals along Upwelling Eastern Boundaries

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  • 1 Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
  • | 2 International Pacific Research Center, University of Hawaii, Honolulu, Hawaii
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Abstract

A simple analytic model is developed to represent the offshore decay of cold sea surface temperature (SST) signals that originate from wind-driven upwelling at a coastal boundary. The model couples an oceanic mixed layer to an atmospheric boundary layer through wind stress and air–sea heat exchange. The primary mechanism that controls SST is a balance between Ekman advection and air–sea exchange. The offshore penetration of the cold SST signal decays exponentially with a length scale that is the product of the ocean Ekman velocity and a time scale derived from the air–sea heat flux and the radiative balance in the atmospheric boundary layer. This cold SST signal imprints on the atmosphere in terms of both the boundary layer temperature and surface wind. Nonlinearities due to the feedback between SST and atmospheric wind, baroclinic instability, and thermal wind in the atmospheric boundary layer all slightly modify this linear theory. The decay scales diagnosed from two-dimensional and three-dimensional eddy-resolving numerical ocean models are in close agreement with the theory, demonstrating that the basic physics represented by the theory remain dominant even in these more complete systems. Analysis of climatological SST off the west coast of the United States also shows a decay of the cold SST anomaly with scale roughly in agreement with the theory.

Corresponding author address: Michael Spall, MS#21, 360 Woods Hole Road, Woods Hole, MA 02543. E-mail: mspall@whoi.edu

Abstract

A simple analytic model is developed to represent the offshore decay of cold sea surface temperature (SST) signals that originate from wind-driven upwelling at a coastal boundary. The model couples an oceanic mixed layer to an atmospheric boundary layer through wind stress and air–sea heat exchange. The primary mechanism that controls SST is a balance between Ekman advection and air–sea exchange. The offshore penetration of the cold SST signal decays exponentially with a length scale that is the product of the ocean Ekman velocity and a time scale derived from the air–sea heat flux and the radiative balance in the atmospheric boundary layer. This cold SST signal imprints on the atmosphere in terms of both the boundary layer temperature and surface wind. Nonlinearities due to the feedback between SST and atmospheric wind, baroclinic instability, and thermal wind in the atmospheric boundary layer all slightly modify this linear theory. The decay scales diagnosed from two-dimensional and three-dimensional eddy-resolving numerical ocean models are in close agreement with the theory, demonstrating that the basic physics represented by the theory remain dominant even in these more complete systems. Analysis of climatological SST off the west coast of the United States also shows a decay of the cold SST anomaly with scale roughly in agreement with the theory.

Corresponding author address: Michael Spall, MS#21, 360 Woods Hole Road, Woods Hole, MA 02543. E-mail: mspall@whoi.edu
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