• Banner, M. L., 1990: Equilibrium spectra of wind waves. J. Phys. Oceanogr.,20, 966–984.

  • ——, and I. R. Young, 1994: Modeling spectral dissipation in the evolution of wind waves. Part I: Assessment of existing model performance. J. Phys. Oceanogr.,24, 1550–1571.

  • Battjes, J. A., T. J. Zitman, and L. H. Holthuijsen, 1987: A reanalysis of the spectra observed in JONSWAP. J. Phys. Oceanogr.,17, 1288–1295.

  • Bendat, J. S., and A. G. Piersol, 1971: Random Data: Analysis and Measurement Procedures. Wiley and Sons, 407 pp.

  • Cote, L. J., and Coauthors, 1960: The directional spectrum of a wind generated sea as determined from data obtained by the Stereo Wave Observation Project. Meteorological Papers, Vol. 2, University Publishers Tech. Rep., New York University, 88 pp.

  • Donelan, M. A., J. Hamilton, and W. H. Hui, 1985: Directional spectra of wind-generated waves. Philos. Trans. Roy. Soc. London,A315, 509–562.

  • Ewans, K. C., 1998: Observations of the directional spectrum of fetch-limited waves. J. Phys. Oceanogr.,28, 495–512.

  • Forristall, G. Z., 1981: Measurements of a saturated range in ocean wave spectra. J. Geophys. Res.,86, 8075–8084.

  • ——, and K. C. Ewans, 1998: Worldwide measurements of directional wave spreading. J. Atmos. Oceanic Technol.,15, 440–469.

  • Hasselmann, D. E., M. Dunckel, and J. A. Ewing, 1980: Directional wave spectra observed during JONSWAP 1973. J. Phys. Oceanogr.,10, 1264–1280.

  • Hwang, P. A., 1997: A study of the wavenumber spectra of short water waves in the ocean. Part II: Spectral model and mean square slope. J. Atmos. Oceanic Technol.,14, 1174–1186.

  • ——, S. Atakturk, M. A. Sletten, and D. B. Trizna, 1996: A study of the wavenumber spectra of short water waves in the ocean. J. Phys. Oceanogr.,26, 1266–1285.

  • ——, E. J. Walsh, W. B. Krabill, R. N. Swift, S. S. Manizade, J. F. Scott, and M. D. Earle, 1998: Airborne remote sensing applications to coastal wave research. J. Geophys. Res.,103, 18 791–18 800.

  • ——, D. W. Wang, E. J. Walsh, W. B. Krabill, and R. N. Swift, 2000a:Airborne measurements of the wavenumber spectra of ocean surface waves. Part II. Directional distribution. J. Phys. Oceanogr.,30, 2768–2787.

  • ——, E. J. Walsh, W. B. Krabill, and R. N. Swift, 2000b: Airborne scanning lidar measurement of ocean waves. J. Remote Sens. Env.,73, 236–246.

  • Jackson, F. C., W. T. Walton, and C. Y. Peng, 1985: A comparison of in situ and airborne radar observations of ocean wave directionality. J. Geophys. Res.,90, 1005–1018.

  • Kahma, K. K., 1981: A study of the growth of the wave spectrum with fetch. J. Phys. Oceanogr.,11, 1503–1515.

  • Kawai, S., K. Okuda, and Y. Toba, 1977: Field data support of three-seconds power law and guσ4 spectral form for growing wind waves. J. Oceanogr. Soc. Japan,33, 137–1515.

  • Komen, G. J., S. Hasselmann, and K. Hasselmann, 1984: On the existence of a fully developed wind–sea spectrum. J. Phys. Oceanogr.,14, 1271–1285.

  • Kondo, J., Y. Fujinawa, and G. Naito, 1973: High-frequency components of ocean waves and their relation to the aerodynamic roughness. J. Phys. Oceanogr.,3, 197–202.

  • Krabill, W. B., and C. F. Martin, 1987: Aircraft positioning using global positioning system carrier phase data. Navigation,34, 1–21.

  • ——, R. H. Thomas, K. Jezek, C. Kuivinen, and S. Manizade, 1995a:Greenland ice sheet thickness changes measured by laser altimetry. Geophys. Res. Lett.,22, 2341–2344.

  • ——, ——, C. F. Martin, R. N. Swift, and E. B. Frederick, 1995b: Accuracy of airborne laser altimetry over the Greenland ice sheet. Int. J. Remote Sens.,16, 1211–1222.

  • Mitsuyasu, H., and Coauthors, 1975: Observation of the directional wave spectra of ocean waves using a cloverleaf buoy. J. Phys. Oceanogr.,5, 750–760.

  • ——, and Coauthors, 1980: Observations of the directional spectra of ocean waves using a cloverleaf buoy. J. Phys. Oceanogr.,10, 286–296.

  • Phillips, O. M., 1958: On some properties of the spectrum of wind-generated ocean waves. J. Mar. Res.,16, 231–240.

  • ——, 1977: The Dynamics of the Upper Ocean. 2d ed. Cambridge University Press, 336 pp.

  • ——, 1985: Spectral and statistical properties of the equilibrium range in wind-generated gravity waves. J. Fluid Mech.,156, 505–531.

  • Pierson, W. J., and L. Moskowitz, 1964: A proposed spectral form for fully-developed wind seas based on the similarity theory of S. A. Kitaigorodskii. J. Geophys. Res.,69, 5181–5190.

  • Thornton, E. B., and R. T. Guza, 1983: Transformation of wave height distribution. J. Geophys. Res.,88, 5925–5938.

  • Toba, Y., 1973: Local balance in the air–sea boundary processes. III. On the spectrum of wind waves. J. Phys. Oceanogr.,3, 579–593.

  • ——, K. Okada, and I. S. F. Jones, 1988: The response of wind-wave spectra to changing winds. Part 1. Increasing winds. J. Phys. Oceanogr.,18, 1231–1240.

  • Walsh, E. J., D. W. Hancock, D. E. Hines, R. N. Swift, and J. F. Scott, 1985: Directional wave spectra measured with the surface contour radar. J. Phys. Oceanogr.,15, 566–592.

  • ——, ——, ——, ——, and ——, 1989: An observation of the directional wave spectrum evolution from shoreline to fully developed. J. Phys. Oceanogr.,19, 670–690.

  • Wyatt, L. R., 1995: The effect of fetch on the directional spectrum of Celtic Sea storm waves. J. Phys. Oceanogr.,25, 1550–1559.

  • Young, I. R., 1994: On the measurement of directional wave spectra. Appl. Ocean Res.,16, 283–294.

  • ——, 1999: Wind Generated Ocean Waves. Elsevier, 288 pp.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 523 144 18
PDF Downloads 182 97 6

Airborne Measurements of the Wavenumber Spectra of Ocean Surface Waves. Part I: Spectral Slope and Dimensionless Spectral Coefficient

View More View Less
  • 1 Oceanography Division, Naval Research Laboratory, Stennis Space Center, Mississippi
  • | 2 NASA/GFSC/WFF, Wallops Island, Virginia
  • | 3 EG&G, WFF, Wallops Island, Virginia
Restricted access

Abstract

An airborne scanning lidar system acquires 3D spatial topography of ocean surface waves. From the spatial data, wavenumber spectra are computed directly. The spectral analyses of two distinctively different wave fields are presented. The first one is a quasi-steady wave field under active wind generation, and the second one is a decaying wave field following a slackening of the wind field. Subtle differences in different representations of the one-dimensional spectrum (omnidirectional, marginal, and traverse) are illustrated. The spectral properties in terms of the dimensionless spectral coefficient and spectral slope in the equilibrium range are investigated using the wavenumber spectra directly computed from the 3D topography of the ocean surface. The results are in excellent agreement with existing data. The rapid data acquisition afforded by an airborne system provides an enhanced capability for studying the spatial variation of a wave field with minimal temporal changes in the environmental forcing conditions. The data of the 3D surface topography are also ideal for the quantitative investigation of the directional properties of a random wave field.

Additional affiliation: NOAA/ETL, Boulder, Colorado.

Corresponding author address: Dr. Paul A. Hwang, Oceanography Division, Naval Research Laboratory, Stennis Space Center, MS 39529-5004.

Email: paul.hwang@nrlssc.navy.mil

Abstract

An airborne scanning lidar system acquires 3D spatial topography of ocean surface waves. From the spatial data, wavenumber spectra are computed directly. The spectral analyses of two distinctively different wave fields are presented. The first one is a quasi-steady wave field under active wind generation, and the second one is a decaying wave field following a slackening of the wind field. Subtle differences in different representations of the one-dimensional spectrum (omnidirectional, marginal, and traverse) are illustrated. The spectral properties in terms of the dimensionless spectral coefficient and spectral slope in the equilibrium range are investigated using the wavenumber spectra directly computed from the 3D topography of the ocean surface. The results are in excellent agreement with existing data. The rapid data acquisition afforded by an airborne system provides an enhanced capability for studying the spatial variation of a wave field with minimal temporal changes in the environmental forcing conditions. The data of the 3D surface topography are also ideal for the quantitative investigation of the directional properties of a random wave field.

Additional affiliation: NOAA/ETL, Boulder, Colorado.

Corresponding author address: Dr. Paul A. Hwang, Oceanography Division, Naval Research Laboratory, Stennis Space Center, MS 39529-5004.

Email: paul.hwang@nrlssc.navy.mil

Save