Statistical aspects of acoustic returns from a wind-driven water surface covered with organic films

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Authors

  • S.J. POGORZELSKI Environmental Acoustics Laboratory, Institute of Experimental Physics, University of Gdańsk, Poland

Abstract

The statistical properties of ultrasonic (10 MHz) signals scattered at a wind-driven water surface covered with different petroleum derivative films of well-defined and oceanographically relevant elastic surface properties were examined under laboratory and open-sea conditions. Evolution of the shape, skewness and kurtosis parameters of the signal distribution as a function of wind speed reflects a principal role played by the film elasticity. The elastic properties of composite sea surfaces likely to be present in nature and consisting of oil spills filled with a surface active material, floating solid particles, bubbles or drops of a third fluid with their important implications in remote sensing techniques are also discussed. A two-spatial scale irregularities distribution of the sea surface (capillary ripples present on tilted faces of long gravity waves) expresses itself in the corresponding signatures of at-sea experiment data.

References

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[2] S.J. POGORZELSKI, Acoustic signatures of organic films floating on the sea surface, Arch. Acoust., 19, 85—108 (1994).

[3] S.J. POGORZELSKI, Ultrasound scattering for oil slicks characterization at sea, Marine Geodesy (1994) (in press).

[4] R. CINI, P.P. LOMBARDINI, C. MANFREDI and E. CINI, Ripple damping due to monomolecular films, J. Colloid Interface Sci., 119, 74—80 (1987).