Presentation + Paper
20 September 2020 Experimental study of wave damping due to ice floes in application to radar remote sensing of the marginal ice zone
Stanislav A. Ermakov, Tatyana N. Lazareva, George V. Leshev, Darya V. Vostryakova
Author Affiliations +
Abstract
Remote sensing of wind waves propagating in the areas covered by ice at initial stages of its formation in the marginal ice zone using radar is an urging problem for mapping ice boundaries and their dynamics. Another aspect of the problem is to investigate possibilities of discrimination between the marginal ice zone and oil spills in radar imagery. This study is focused on modeling the damping of surface waves due to ice floes in laboratory and field experiment. Laboratory experiments were carried out is a container filled with pure water in order to exclude the effect of surfactant films on wave damping. The container was mounted on a vibration table, so that surface gravity-capillary waves (GCW) could be parametrically generated in the container when the amplitude of the vibrations exceeded some threshold level. The wave damping coefficient could be retrieved when measuring the threshold. The floes in experiment were modeled using thin plastic pieces of two different sizes, the relative square of the “floe” coverage of the water surface was controlled in experiment. The dependences of the damping coefficient at different relations between the surface wavelength and the floe dimensions as functions of the floe coverage area were obtained. It is obtained that the damping of gravity-capillary waves in the presence of floes comparable in size with GCW can be one to two orders of magnitude greater that the wave damping due to inextensible film. Preliminary field experiments have been conducted on the Gorky Water Reservoir using a research catamaran vessel of the Institute of Applied Physics. Plywood pieces with sizes several times smaller that the studied surface wavelengths were used as imitators of ice floes and were deployed in between the catamaran hulls. Surface waves propagating between the halls were generated mechanically by a vertically oscillating motor boat. The amplitude of attenuating surface waves due to the “plywood floes” was measured with wire gauges mounted at the bow and the stern of the catamaran. The damping distance due to ice floes obtained in the field experiment was estimated as about 10 wavelengths thus indicating that that wave suppression due to the floes was essentially stronger than the viscous wave damping for clean or contaminated water surface. Wave damping observed both in the laboratory and field experiments can be comparable with the wave damping due to crude oil/oil emulsion films, so the problem of discrimination between, e.g. grease ice and oil spills in radar imagery can be nontrivial.
Conference Presentation
© (2020) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Stanislav A. Ermakov, Tatyana N. Lazareva, George V. Leshev, and Darya V. Vostryakova "Experimental study of wave damping due to ice floes in application to radar remote sensing of the marginal ice zone", Proc. SPIE 11529, Remote Sensing of the Ocean, Sea Ice, Coastal Waters, and Large Water Regions 2020, 1152909 (20 September 2020); https://doi.org/10.1117/12.2574082
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Radar

Remote sensing

Basic research

Systems modeling

Wave propagation

Wave sensors

Back to Top