• Barrick, D. E., 1971a: Theory of HF and VHF propagation across the rough sea, 1: The effective surface impedance for a slightly rough highly conducting medium at grazing incidence. Radio Sci., 6, 517526, doi:10.1029/RS006i005p00517.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Barrick, D. E., 1971b: Theory of HF and VHF propagation across the rough sea, 2: Application to HF and VHF propagation above the sea. Radio Sci., 6, 527533, doi:10.1029/RS006i005p00527.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Barrick, D. E., 1972: First-order theory and analysis of MF/HF/VHF scatter from the sea. IEEE Trans. Antennas Propag., 20, 210, doi:10.1109/TAP.1972.1140123.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Barrick, D. E., 1977: Extraction of wave parameters from measured HF radar sea-echo Doppler spectra. Radio Sci., 12, 415424, doi:10.1029/RS012i003p00415.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Barrick, D. E., M. W. Evans, and B. L. Weber, 1977: Ocean surface currents mapped by radar. Science, 198, 4313, 138144, doi:10.1126/science.198.4313.138.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Chavanne, C., P. Flament, G. Carter, M. Merrifield, D. Luther, E. Zaron, and K.-W. Gurgel, 2010: The surface expression of semidiurnal internal tides near a strong source at Hawaii. Part I: Observations and numerical predictions. J. Phys. Oceanogr., 40, 11551179, doi:10.1175/2010JPO4222.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cosoli, S., A. Mazzoldi, and M. Gačić, 2010: Validation of surface current measurements in the northern Adriatic Sea from high-frequency radars. J. Atmos. Oceanic Technol., 27, 908919, doi:10.1175/2009JTECHO680.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Crombie, D. D., 1955: Doppler spectrum of sea echo at 13.56 Mc./s. Nature, 175, 681682, doi:10.1038/175681a0.

  • Fernandez, D., L. Meadows, J. Vesecky, C. Teague, J. Paduan, and P. Hansen, 2000: Surface current measurements by HF radar in freshwater lakes. IEEE J. Oceanic Eng., 25, 458471, doi:10.1109/48.895353.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Foreman, M., R. Walters, R. Henry, C. Keller, and A. Dolling, 1995: A tidal model for Juan-de-Fuca Strait and the Southern Strait of Georgia. J. Geophys. Res., 100, 721740, doi:10.1029/94JC02721.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Forget, P., and P. Broche, 1991: A study of VHF radio wave propagation over a water surface of variable conductivity. Radio Sci., 26, 12291237, doi:10.1029/91RS01413.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Forget, P., P. Broche, and J. C. de Maistre, 1982: Attenuation with distance and wind speed of HF surface waves over the ocean. Radio Sci., 17, 599610, doi:10.1029/RS017i003p00599.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gurgel, K.-W., H.-H. Essen, and S. Kingsley, 1999a: High-frequency radars: Physical limitations and recent developments. Coastal Eng., 37, 201218, doi:10.1016/S0378-3839(99)00026-5.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gurgel, K.-W., H.-H. Essen, and T. Schlick, 1999b: Tracking of fresh-water plumes in Dutch coastal waters by means of HF radar. IGARSS’99 Proceedings: Remote Sensing of the System Earth—A Challenge for the 21st Century, T. I. Stein, Ed., Vol. 5, IEEE, 2548–2550, doi:10.1109/IGARSS.1999.771572.

    • Crossref
    • Export Citation
  • Halverson, M. J., 2009: Multi-timescale analysis of the salinity and algal biomass of the Fraser River plume from repeated ferry transects. Ph.D. thesis, University of British Columbia, 181 pp., doi:10.14288/1.0053481.

    • Crossref
    • Export Citation
  • Halverson, M. J., and R. Pawlowicz, 2008: Estuarine forcing of a river plume by river flow and tides. J. Geophys. Res., 113, C090330, doi:10.1029/2008JC004844.

    • Search Google Scholar
    • Export Citation
  • Halverson, M. J., and R. Pawlowicz, 2011: Entrainment and flushing time in the Fraser River estuary and plume from a steady salt balance analysis. J. Geophys. Res., 116, C08023, doi:10.1029/2010JC006793.

    • Search Google Scholar
    • Export Citation
  • Halverson, M. J., and S. W. Fleming, 2015: Complex network theory, streamflow, and hydrometric monitoring system design. Hydrol. Earth Syst. Sci., 19, 33013318, doi:10.5194/hess-19-3301-2015.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Halverson, M. J., and R. Pawlowicz, 2016: Tide, wind, and river forcing of the surface currents in the Fraser River plume. Atmos.–Ocean, 54, 131152, doi:10.1080/07055900.2016.1138927.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hansen, P., 1977: Measurements of basic transmission loss for HF ground wave propagation over seawater. Radio Sci., 12, 397404, doi:10.1029/RS012i003p00397.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hasselmann, K., 1971: Determination of ocean wave spectra from Doppler radio return from the sea surface. Nature, 229, 1617, doi:10.1038/physci229016a0.

    • Search Google Scholar
    • Export Citation
  • Heron, M., and R. Rose, 1986: On the application of HF ocean radar to the observation of temporal and spatial changes in wind direction. IEEE J. Oceanic Eng., 11, 210218, doi:10.1109/JOE.1986.1145173.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hinatsu, M., Y. Tsukada, H. Tomita, and A. Harashima, 2004: Study on estimation of original location of water sampled through inlet set on volunteer observing ship. J. Adv. Mar. Sci. Technol. Soc., 9, 3746.

    • Search Google Scholar
    • Export Citation
  • IOC, SCOR, and IAPSO, 2010: The International Thermodynamic Equation of Seawater—2010: Calculations and use of thermodynamic properties. Intergovernmental Oceanographic Commission Manuals and Guides 56, 207 pp.

  • Kamli, E., C. Chavanne, and D. Dumont, 2016: Experimental assessment of the performance of high-frequency CODAR and WERA radars to measure ocean currents in partially ice-covered waters. J. Atmos. Oceanic Technol., 33, 539550, doi:10.1175/JTECH-D-15-0143.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lyons, R. S., and D. E. Barrick, 1984: Attenuation rates of coastal radar signals at 25 MHz. Radio Sci., 19, 319324, doi:10.1029/RS019i001p00319.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Meadows, L. A., C. Whelan, D. Barrick, R. Kroodsma, C. Ruf, C. C. Teague, G. A. Meadows, and S. Wang, 2013: High frequency radar and its application to fresh water. J. Great Lakes Res., 39 (Suppl. 1), 183193, doi:10.1016/j.jglr.2013.01.002.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Meulé, S., P. Hill, and C. Pinazo, 2007: Wave dynamics over Roberts Bank, British Columbia: Processes and modelling. Geological Survey of Canada Tech. Rep. 2007-A11, 9 pp., doi:10.4095/224297.

    • Crossref
    • Export Citation
  • Norton, K. A., 1936: The propagation of radio waves over the surface of the Earth and in the upper atmosphere. Proc. Inst. Radio Engr., 24, 13671387, doi:10.1109/JRPROC.1936.227360.

    • Search Google Scholar
    • Export Citation
  • Pawlowicz, R., 2015: The absolute salinity of seawater diluted by riverwater. Deep-Sea Res. I, 101, 7179, doi:10.1016/j.dsr.2015.03.006.

  • Pawlowicz, R., O. Riche, and M. Halverson, 2007: The circulation and residence time of the Strait of Georgia using a simple mixing-box approach. Atmos.–Ocean, 45, 173193, doi:10.3137/ao.450401.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Royer, L., and W. Emery, 1982: Variations of the Fraser River plume and their relationship to forcing by tide, wind and discharge. Atmos.–Ocean, 20, 357372, 9649151, doi:10.1080/07055900.1982.9649151.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Savidge, D., J. Amft, A. Gargett, M. Archer, D. Conley, G. Voulgaris, L. Wyatt, and K.-W. Gurgel, 2011: Assessment of WERA long-range HF-radar performance from the user’s perspective. 2011 IEEE/OES/CWTM Tenth Working Conference on Current, Waves and Turbulence Measurements (CWTM), J. Rizoli White and A. J. Williams III, Eds., IEEE, 31–38, doi:10.1109/CWTM.2011.5759520.

    • Crossref
    • Export Citation
  • Shearman, E., 1983: Propagation and scattering in MF/HF groundwave radar. IEE Proc., 130F, 579590, doi:10.1049/ip-f-1:19830092.

  • Shen, W., K.-W. Gurgel, G. Voulgaris, T. Schlick, and D. Stammer, 2012: Wind-speed inversion from HF radar first-order backscatter signal. Ocean Dyn., 62, 105121, doi:10.1007/s10236-011-0465-9.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Smith, S. D., 1988: Coefficients for sea surface wind stress, heat flux, and wind profiles as a function of wind speed and temperature. J. Geophys. Res., 93, 15 46715 472, doi:10.1029/JC093iC12p15467.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Stewart, R. H., and J. W. Joy, 1974: HF radio measurement of surface currents. Deep-Sea Res. Oceanogr. Abstr., 21, 10391049, doi:10.1016/0011-7471(74)90066-7.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Thomson, R. E., 1981: Oceanography of the British Columbia Coast. Canadian Special Publications of Fisheries and Aquatic Sciences, Vol. 56, Dept. of Fisheries and Oceans, Institute of Ocean Sciences, 291 pp.

  • Wang, C., 2015: Oxygen budgets and productivity estimates in the Strait of Georgia from a continuous ferry-based monitoring system. M.S. thesis, Dept. of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, 124 pp.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 299 190 0
PDF Downloads 245 150 0

Dependence of 25-MHz HF Radar Working Range on Near-Surface Conductivity, Sea State, and Tides

View More View Less
  • 1 Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada
  • | 2 Institut des Sciences de la Mer de Rimouski, Université du Québec à Rimouski, Rimouski, Quebec, Canada
Restricted access

Abstract

A 1.6-yr time series of radial current velocity from a 25-MHz high-frequency radar system located near a coastal river plume is analyzed to determine how the working range varies in response to changing near-surface conductivity, sea state, and tides. Working range is defined as the distance to the farthest radial velocity solution along a fixed bearing. A comparison to spatially resolved near-surface conductivity measurements from an instrumented ferry shows that fluctuations in conductivity had the largest impact of the three factors considered. The working range increases nearly linearly with increasing conductivity, almost doubling from 19.4 km at 0.9 S m−1 to 37.4 km at 3.5 S m−1, which yields a slope of 7.0 km per S m−1. The next largest factor was sea state, which was investigated using measured winds. The working range increases linearly at a rate of 1 km per m s−1 of wind speed over the range of 0.5–6.5 m s−1, but it decreases weakly for wind speeds higher than 7.5 m s−1. Finally, a power spectrum of the working range time series reveals variability at tidal frequencies. Tides cause about 3 km of range variation; however, the mechanism(s) underlying this are not known explicitly. Evidence for both sea level height and the interaction of tidal currents with sea state are presented.

© 2017 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 e-mail: Mark Halverson, mhalvers@eos.ubc.ca

Abstract

A 1.6-yr time series of radial current velocity from a 25-MHz high-frequency radar system located near a coastal river plume is analyzed to determine how the working range varies in response to changing near-surface conductivity, sea state, and tides. Working range is defined as the distance to the farthest radial velocity solution along a fixed bearing. A comparison to spatially resolved near-surface conductivity measurements from an instrumented ferry shows that fluctuations in conductivity had the largest impact of the three factors considered. The working range increases nearly linearly with increasing conductivity, almost doubling from 19.4 km at 0.9 S m−1 to 37.4 km at 3.5 S m−1, which yields a slope of 7.0 km per S m−1. The next largest factor was sea state, which was investigated using measured winds. The working range increases linearly at a rate of 1 km per m s−1 of wind speed over the range of 0.5–6.5 m s−1, but it decreases weakly for wind speeds higher than 7.5 m s−1. Finally, a power spectrum of the working range time series reveals variability at tidal frequencies. Tides cause about 3 km of range variation; however, the mechanism(s) underlying this are not known explicitly. Evidence for both sea level height and the interaction of tidal currents with sea state are presented.

© 2017 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 e-mail: Mark Halverson, mhalvers@eos.ubc.ca
Save