Modeling of Current Features in Gulf Stream SAR Imagery

Abstract : The theoretical formulation, numerical implementation, and testing of NRL's recently developed time-dependent ocean wave model (NTOW) is described. The propagation of the wave field is computed via the action density conservation equation for general time varying currents, winds, and bathymetry. The NTOW model is used to predict wave-current interaction effects in a region of strong surface convergence near the edge of the Gulf Stream off Cape Hatteras. The computed wave field is used in conjunction with a composite scattering radar model to derive radar imagery. Our radar predictions are compared with real aperture radar data collected during the NRL high-resolution remote sensing experiment (Valenzuela, 1991). Remote sensing, Ocean currents, Wave-current interaction, Gulf Stream, SAR imagery.

[1]  F. Riedel,et al.  Proposed Model for the Elevation Spectrum of a Wind-Roughened Sea Surface , 1979 .

[2]  K. Gastel.  Nonlinear interactions of gravity-capillary waves: Lagrangian theory and effects on the spectrum , 1987, Journal of Fluid Mechanics.

[3]  K. Hasselmann.  On the non-linear energy transfer in a gravity-wave spectrum Part 1. General theory , 1962, Journal of Fluid Mechanics.

[4]  Hendrik L. Tolman,et al.  A Third-Generation Model for Wind Waves on Slowly Varying, Unsteady, and Inhomogeneous Depths and Currents , 1991 .

[5]  G. B. Whitham,et al.  Variational methods and applications to water waves , 1967, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[6]  K. Hasselmann.  On the non-linear energy transfer in a gravity wave spectrum Part 2. Conservation theorems; wave-particle analogy; irrevesibility , 1963, Journal of Fluid Mechanics.

[7]  O. Phillips.  On the generation of waves by turbulent wind , 1957, Journal of Fluid Mechanics.

[8]  K. Hasselmann.  WEAK-INTERACTION THEORY OF OCEAN WAVES , 1967 .

[9]  David R. Lyzenga,et al.  Interaction of short surface and electromagnetic waves with ocean fronts , 1991 .

[10]  G. Valenzuela,et al.  Nonlinear energy transfer in gravity–capillary wave spectra, with applications , 1972, Journal of Fluid Mechanics.

[11]  F. Askari,et al.  The July 1990 Gulf Stream Experiment , 1991, [Proceedings] IGARSS'91 Remote Sensing: Global Monitoring for Earth Management.

[12]  J. Wright.  A new model for sea clutter , 1968 .

[13]  W. Plant.  A relationship between wind stress and wave slope , 1982 .

[14]  F. Bretherton,et al.  Wavetrains in inhomogeneous moving media , 1968, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[15]  B. Hughes.  The effect of internal waves on surface wind waves 2. Theoretical analysis , 1978 .