Attenuation of capillary and gravity waves at sea by monomolecular organic surface films

Abstract

During the MARSEN 79 experiment, attenuation of capillary and gravity water waves by two oleyl alcohol and one methyl oleate surface films (‘slicks’) was investigated. A slight influence of an oleyl alcohol slick occurs at frequencies between 0.5 Hz and 0.7 Hz and above 0.7 Hz (wavelength L = 3.2 m) wave attenuation becomes significant. A methyl oleate slick causes only a slight wave damping in the frequency range ƒ<5 Hz (L>6.7 cm). In the capillary wave range ƒ≥14 Hz the wave‐damping characteristics for the two surface film substances are comparable. In the high‐frequency capillary wave range ƒ>20 Hz, however, methyl oleate surface films act more strongly on the wave field, as was demonstrated by additional wind‐wave tunnel experiments. The different wave attenuation characteristics of these two surface active compounds are attributed to different interaction between their hydrophilic part and the adjacent water layer.

State of the art satellite and airborne marine oil spill remote sensing: Application to the BP Deepwater Horizon oil spill

“…Alcohols and other surfactant films induce maximum dampening in the range of 2-10 Hz (Trivero & Biamino, 2010). Over the years, many studies have investigated oil releases and other substances emulating oil releases with SAR and scatterometers, including multiple frequency and multiple polarizations from aircraft and towers (Gade et al, 1998a;Hühnerfuss et al, 1983Hühnerfuss et al, , 1996Wismann et al, 1998). Most showed increased oil-damping attenuation associated with higher radar frequency; some also identified oilinduced scattering unrelated to Bragg scattering.…”

“…These thin oil sheens appear to affect primarily waves from 0.12 to 0.7 Hz, spanning capillary waves to short gravity waves. However, extensive slicks can dampen longer ocean waves (Hühnerfuss et al, 1983). Alcohols and other surfactant films induce maximum dampening in the range of 2-10 Hz (Trivero & Biamino, 2010).…”

Characterization and discrimination of evolving mineral and plant oil slicks based on L-band synthetic aperture radar (SAR)

“…These capabilities are becoming more important as the Arctic is opened to oil transport and extraction. Although radar has long been used for mapping the spatial extent of oil slicks [1][2][3] , the large release volumes of the Deepwater Horizon (DWH) spill in 2010 were studied extensively to show synthetic aperture radar (SAR) capable of characterizing properties needed to direct responders to recoverable oil, namely volumetric oil fraction 4,5 or thickness 6 . Although the nascent studies based on the DWH spill provided some evidence of SAR's suitability for directing emergency responders to the highest impact areas, robust verification of the results was not obtained during the chaos of the spill response to that major disaster.…”

Partially Supervised Oil-Slick Detection by SAR Imagery Using Kernel Expansion

“…A slick at the ocean surface damps gravity-capillary waves, as explained by Marangoni's theory [10], which is detailed in [11]- [15]. Wave damping is due to the decrease in the surface stress, which is associated with film elasticity, and also to the slick nature, density, and surface viscosity.…”