• Androulidakis, Y., and Coauthors, 2018: Influence of river-induced fronts on hydrocarbon transport: A multiplatform observational study. J. Geophys. Res. Oceans, 132, 32593285, https://doi.org/10.1029/2017JC013514.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Appendini, C. M., A. Torres-Freyermuth, P. Salles, J. López-González, and E. T. Mendoza, 2014: Wave climate and trends for the Gulf of Mexico: A 30-yr wave hindcast. J. Climate, 27, 16191632, https://doi.org/10.1175/JCLI-D-13-00206.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Austin, R. W., and T. J. Petzold, 1986: Spectral dependence of the diffuse attenuation coefficient of light in ocean waters. Opt. Eng., 25, 253471, https://doi.org/10.1117/12.7973845.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Bennett, A. F., 1987: A Lagrangian analysis of turbulent diffusion. Rev. Geophys., 25, 799822, https://doi.org/10.1029/RG025i004p00799.

  • Beron-Vera, F. J., and J. H. LaCasce, 2016: Statistics of simulated and observed pair separations in the Gulf of Mexico. J. Phys. Oceangr., 46, 21832199, https://doi.org/10.1175/JPO-D-15-0127.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Berta, M., A. Griffa, T. M. Özgökmen, and A. C. Poje, 2016: Submesoscale evolution of surface drifter triads in the Gulf of Mexico. Geophys. Res. Lett., 43, 11 75111 759, https://doi.org/10.1002/2016GL070357.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Capet, X., J. C. McWilliams, M. J. Molemaker, and A. F. Shchepetkin, 2008a: Mesoscale to submesoscale transition in the California Current System. Part I: Flow structure, eddy flux, and observational tests. J. Phys. Oceanogr., 38, 2943, https://doi.org/10.1175/2007JPO3671.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Capet, X., J. C. McWilliams, M. J. Molemaker, and A. F. Shchepetkin, 2008b: Mesoscale to submesoscale transition in the California Current System. Part II: Frontal processes. J. Phys. Oceanogr., 38, 4464, https://doi.org/10.1175/2007JPO3672.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Capet, X., J. C. McWilliams, M. J. Molemaker, and A. F. Shchepetkin, 2008c: Mesoscale to submesoscale transition in the California Current System. Part III: Energy balance and flux. J. Phys. Oceanogr., 38, 22562269, https://doi.org/10.1175/2008JPO3810.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Clark, D. B., L. Lenain, F. Feddersen, E. Boss, and R. T. Guza, 2014: Aerial imaging of fluorescent dye in the near shore. J. Atmos. Oceanic Technol., 31, 14101421, https://doi.org/10.1175/JTECH-D-13-00230.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Craik, A. D. D., and S. Leibovich, 1976: A rational model for Langmuir circulations. J. Fluid Mech., 73, 401426, https://doi.org/10.1017/S0022112076001420.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • D’Asaro, E. A., and Coauthors, 2018: Ocean convergence and the dispersion of flotsam. Proc. Natl. Acad. Sci. USA, 115, 11621167, https://doi.org/10.1073/pnas.1718453115.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Emery, W. J., and R. E. Thomson, 2001: Data Analysis Methods in Physical Oceanography. Elsevier Science, 654 pp.

  • Farmer, D., and M. Li, 1995: Patterns of bubble clouds organized by Langmuir circulation. J. Phys. Oceanogr., 25, 14261440, https://doi.org/10.1175/1520-0485(1995)025<1426:POBCOB>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Garvine, R. W., 1974: Dynamics of small-scale oceanic fronts. J. Phys. Oceanogr., 4, 557569, https://doi.org/10.1175/1520-0485(1974)004<0557:DOSSOF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hedley, J. D., A. R. Harborne, and P. J. Mumby, 2005: Simple and robust removal of sun glint for mapping shallow-water benthos. Int. J. Remote Sens., 26, 21072112, https://doi.org/10.1080/01431160500034086.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Huang, P. Q., Y. Z. Lu, and S. Q. Zhou, 2018: An objective method for determining ocean mixed layer depth with applications to WOCE data. J. Atmos. Oceanic Technol., 35, 441458, https://doi.org/10.1175/JTECH-D-17-0104.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kenyon, K. E., 1970: Stokes transport. J. Geophys. Res., 75, 11331135, https://doi.org/10.1029/JC075i006p01133.

  • LaCasce, J. H., 2008: Statistics from Lagrangian observations. Prog. Oceanogr., 77, 129, https://doi.org/10.1016/j.pocean.2008.02.002.

  • LaCasce, J. H., and C. Ohlmann, 2003: Relative dispersion at the surface of the Gulf of Mexico. J. Mar. Res., 61, 285312, https://doi.org/10.1357/002224003322201205.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Large, W. G., and S. Pond, 1982: Sensible and latent heat flux measurements over the ocean. J. Phys. Oceanogr., 12, 464482, https://doi.org/10.1175/1520-0485(1982)012<0464:SALHFM>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Large, W. G., E. G. Patton, A. K. DuVivier, P. P. Sullivan, and L. Romero, 2019: Similarity theory in the surface layer of large-eddy simulations of the wind, wave and buoyancy forced Southern Ocean. J. Phys. Oceanogr., 49, 21652187, https://doi.org/10.1175/JPO-D-18-0066.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Liang, J.-H., X. Wan, K. A. Rose, P. P. Sullivan, and J. C. McWilliams, 2018: Horizontal dispersion of buoyant materials in the ocean surface boundary layer. J. Phys. Oceanogr., 48, 21032125, https://doi.org/10.1175/JPO-D-18-0020.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • List, E. J., G. Gartrell, and C. D. Winant, 1990: Diffusion and dispersion in coastal waters. J. Hydraul. Eng., 116, 11581179, https://doi.org/10.1061/(ASCE)0733-9429(1990)116:10(1158).

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., 2016: Submesoscale currents in the ocean. Proc. Roy. Soc. London., 472, 20160117, https://doi.org/10.1098/rspa.2016.0117.

    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., P. P. Sullivan, and C.-H. Moeng, 1997: Langmuir turbulence in the ocean. J. Fluid Mech., 334, 130, https://doi.org/10.1017/S0022112096004375.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., J. M. Restrepo, and E. M. Lane, 2004: An asymptotic theory for the interaction of waves and currents in coastal waters. J. Fluid Mech., 511, 135178, https://doi.org/10.1017/S0022112004009358.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., J. Gula, M. J. Molemaker, L. Renault, and A. F. Shchepetkin, 2015: Filament frontogenesis by boundary layer turbulence. J. Phys. Oceanogr., 45, 19882005, https://doi.org/10.1175/JPO-D-14-0211.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Melville, W. K., L. Lenain, D. R. Cayan, M. Kahru, J. P. Kleissl, P. Linden, and N. M. Statom, 2016: The Modular Aerial Sensing System. J. Atmos. Oceanic Technol., 33, 11691184, https://doi.org/10.1175/JTECH-D-15-0067.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mensa, J. A., T. M. Özgökmen, A. C. Poje, and J. Imberger, 2015: Material transport in a convective surface mixed layer under weak wind forcing. Ocean Modell., 96, 226242, https://doi.org/10.1016/j.ocemod.2015.10.006.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Moeller, C. C., O. K. Huh, H. H. Roberts, L. E. Gumley, and W. P. Menzel, 1993: Response of Louisiana coastal environments to a cold front passage. J. Coastal Res., 9, 434447, https://www.jstor.org/stable/4298101.

    • Search Google Scholar
    • Export Citation
  • Molinari, R., and A. D. Kirwan, 1975: Calculations of differential kinematic properties from Lagrangian observations in the western Caribbean Sea. J. Phys. Oceanogr., 5, 483491, https://doi.org/10.1175/1520-0485(1975)005<0483:CODKPF>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mueller, J. L., 2000: SeaWiFS algorithm for the diffuse attenuation coefficient, K(490), using water-leaving radiances at 490 and 555 nm. SeaWiFS Postlaunch Calibration and Validation Analyses, Part 3, S. B. Hooker and E. R. Firestone, Eds., NASA/TM-2000-206892, Vol. 11, 24–27, https://oceancolor.gsfc.nasa.gov/SeaWiFS/TECH_REPORTS/PLVol11.pdf.

  • Niiler, P. P., A. S. Sybrandy, K. Bi, P. M. Poulain, and D. Bitterman, 1995: Measurements of the water-following capability of holey-sock and TRISTAR drifters. Deep-Sea Res. I, 42, https://doi.org/10.1016/0967-0637(95)00076-3.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • O’Donnell, J., G. O. Marmorino, and L. T. Clifford, 1998: Convergence and downwelling at a river plume front. J. Phys. Oceanogr., 28, 14811495, https://doi.org/10.1175/1520-0485(1998)028<1481:CADAAR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ohlmann, J. C., P. F. White, A. L. Sybrandy, and P. P. Niiler, 2005: GPS-cellular drifter technology for coastal ocean observing systems. J. Atmos. Oceanic Technol., 22, 13811388, https://doi.org/10.1175/JTECH1786.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ohlmann, J. C., J. H. LaCasce, L. Washburn, A. J. Mariano, and B. Emery, 2012: Relative dispersion observations and trajectory modeling in the Santa Barbara Channel. J. Geophys. Res., 117, C05040, https://doi.org/10.1029/2011JC007810.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ohlmann, J. C., M. J. Molemaker, B. Baschek, B. Holt, G. Marmorino, and G. Smith, 2017: Drifter observations of submesoscale flow kinematics in the coastal ocean. Geophys. Res. Lett., 44, 330337, https://doi.org/10.1002/2016GL071537.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ohlmann, J. C., L. Romero, E. Pallàs-Sanz, and P. Perez-Brunius, 2019: Anisotropy in coastal ocean relative dispersion observations. Geophys. Res. Lett., 46, 879888, https://doi.org/10.1029/2018GL081186.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Okubo, A., and C. C. Ebbesmeyer, 1976: Determination of vorticity, divergence, and deformation rates from analysis of drogue observations. Deep-Sea Res., 23, 349352, https://doi.org/10.1016/0011-7471(76)90875-5.

    • Search Google Scholar
    • Export Citation
  • Poje, A. C., A. C. Haza, T. M. Özgökmen, M. G. Magaldi, and Z. D. Garraffo, 2010: Resolution dependent relative dispersion statistics in a hierarchy of ocean models. Ocean Modell., 31, 3650, https://doi.org/10.1016/j.ocemod.2009.09.002.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Poje, A. C., and Coauthors, 2014: Submesoscale dispersion in the vicinity of the Deepwater Horizon spill. Proc. Natl. Acad. Sci. USA, 111, 12 69312 698, https://doi.org/10.1073/pnas.1402452111.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Romero, L., and W. K. Melville, 2010: Airborne observations of fetch-limited waves in the Gulf of Tehuantepec. J. Phys. Oceanogr., 40, 441465, https://doi.org/10.1175/2009JPO4127.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Romero, L., W. K. Melville, and J. M. Kleiss, 2012: Spectral energy dissipation due to surface-wave breaking. J. Phys. Oceanogr., 42, 14211444, https://doi.org/10.1175/JPO-D-11-072.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Romero, L., Y. Uchiyama, J. C. Ohlmann, J. C. McWilliams, and D. A. Siegel, 2013: Simulations of nearshore particle-pair dispersion in Southern California. J. Phys. Oceanogr., 43, 18621879, https://doi.org/10.1175/JPO-D-13-011.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Romero, L., D. A. Siegel, J. C. McWilliams, Y. Uchiyama, and C. Jones, 2016: Characterizing stormwater dispersion and dilution from small coastal streams. J. Geophys. Res. Oceans, 121, 39263943, https://doi.org/10.1002/2015JC011323.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Romero, L., L. Lenain, and W. K. Melville, 2017: Observations of surface-wave-current interaction. J. Phys. Oceanogr., 47, 615632, https://doi.org/10.1175/JPO-D-16-0108.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sea-Bird, 2017: Seasoft V2: SBE data processing CTD data processing & plotting software for Windows. Sea-Bird Scientific, 177 pp.

  • Sullivan, P. P., and J. C. McWilliams, 2018: Frontogenesis and frontal arrest of a dense filament in the oceanic surface boundary layer. J. Fluid Mech., 837, 341380, https://doi.org/10.1017/jfm.2017.833.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sullivan, P. P., J. C. McWilliams, and W. K. Melville, 2004: The oceanic boundary layer driven by wave breaking with stochastic variability. Part 1. Direct numerical simulations. J. Fluid Mech., 507, 143174, https://doi.org/10.1017/S0022112004008882.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sullivan, P. P., J. C. McWilliams, and W. K. Melville, 2007: Surface gravity wave effects in the oceanic boundary layer: Large-eddy simulation with vortex force and stochastic breakers. J. Fluid Mech., 593, 405452, https://doi.org/10.1017/S002211200700897X.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sullivan, P. P., L. Romero, J. C. McWilliams, and W. K. Melville, 2012: Transient evolution of Langmuir Turbulence in ocean boundary layers driven by hurricane winds and waves. J. Phys. Oceanogr., 42, 19591980, https://doi.org/10.1175/JPO-D-12-025.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Van Roekel, L. P., B. Fox-Kemper, P. P. Sullivan, P. E. Hamlington, and S. R. Haney, 2012: The form and orientation of Langmuir cells for misaligned winds and waves. J. Geophys. Res. 117, C05001, https://doi.org/10.1029/2011JC007516.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Whilden, K. A., S. A. Socolofsky, K. A. Chang, and J. L. Irish, 2014: Using surface drifter observations to measure tidal vortices and relative diffusion at Aransas Pass, Texas. Environ. Fluid Mech., 14, 11471172, https://doi.org/10.1007/s10652-014-9361-4.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wilson, J. F., Jr., E. D. Cobb, and F. A. Kilpatrick, 1968: Fluorometric producers for dye tracing. USGS Open-File Rep. 84-234, 53 pp., https://pubs.usgs.gov/of/1984/0234/report.pdf.

    • Crossref
    • Export Citation
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Coincident Observations of Dye and Drifter Relative Dispersion over the Inner Shelf

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  • 1 Earth Research Institute, University of California, Santa Barbara, Santa Barbara, California
  • 2 Centro de Investigación y Educación Superior de Ensenada, Ensenada, Mexico
  • 3 Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California
  • 4 Centro de Investigación y Educación Superior de Ensenada, Ensenada, Mexico
  • 5 Earth Research Institute, University of California, Santa Barbara, Santa Barbara, California
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Abstract

Coincident Lagrangian observations of coastal circulation with surface drifters and dye tracer were collected to better understand small-scale physical processes controlling transport and dispersion over the inner shelf in the Gulf of Mexico. Patches of rhodamine dye and clusters of surface drifters at scales of O(100) m were deployed in a cross-shelf array within 12 km from the coast and tracked for up to 5 h with airborne and in situ observations. The airborne remote sensing system includes a hyperspectral sensor to track the evolution of dye patches and a lidar to measure directional wavenumber spectra of surface waves. Supporting in situ measurements include a CTD with a fluorometer to inform on the stratification and vertical extent of the dye and a real-time towed fluorometer for calibration of the dye concentration from hyperspectral imagery. Experiments were conducted over a wide range of conditions with surface wind speed between 3 and 10 m s−1 and varying sea states. Cross-shelf density gradients due to freshwater runoff resulted in active submesoscale flows. The airborne data allow characterization of the dominant physical processes controlling the dispersion of passive tracers such as freshwater fronts and Langmuir circulation. Langmuir circulation was identified in dye concentration maps on most sampling days except when the near surface stratification was strong. The observed relative dispersion is anisotropic with eddy diffusivities O(1) m2 s−1. Near-surface horizontal dispersion is largest along fronts and in conditions dominated by Langmuir circulation is larger in the crosswind direction. Surface convergence at fronts resulted in strong vertical velocities of up to −66 m day−1.

Supplemental information related to this paper is available at the Journals Online website: https://doi.org/10.1175/JPO-D-19-0056.s1.

© 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Leonel Romero, leromero@eri.ucsb.edu

Abstract

Coincident Lagrangian observations of coastal circulation with surface drifters and dye tracer were collected to better understand small-scale physical processes controlling transport and dispersion over the inner shelf in the Gulf of Mexico. Patches of rhodamine dye and clusters of surface drifters at scales of O(100) m were deployed in a cross-shelf array within 12 km from the coast and tracked for up to 5 h with airborne and in situ observations. The airborne remote sensing system includes a hyperspectral sensor to track the evolution of dye patches and a lidar to measure directional wavenumber spectra of surface waves. Supporting in situ measurements include a CTD with a fluorometer to inform on the stratification and vertical extent of the dye and a real-time towed fluorometer for calibration of the dye concentration from hyperspectral imagery. Experiments were conducted over a wide range of conditions with surface wind speed between 3 and 10 m s−1 and varying sea states. Cross-shelf density gradients due to freshwater runoff resulted in active submesoscale flows. The airborne data allow characterization of the dominant physical processes controlling the dispersion of passive tracers such as freshwater fronts and Langmuir circulation. Langmuir circulation was identified in dye concentration maps on most sampling days except when the near surface stratification was strong. The observed relative dispersion is anisotropic with eddy diffusivities O(1) m2 s−1. Near-surface horizontal dispersion is largest along fronts and in conditions dominated by Langmuir circulation is larger in the crosswind direction. Surface convergence at fronts resulted in strong vertical velocities of up to −66 m day−1.

Supplemental information related to this paper is available at the Journals Online website: https://doi.org/10.1175/JPO-D-19-0056.s1.

© 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Leonel Romero, leromero@eri.ucsb.edu

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