Experiments on waves in oil and ice

In the project "Experiments on waves in oil and ice", the full coupling between waves, oil and ice will be investigated. This includes the ability to remotely detect aspects of the surface cover, such as the amount of oil or ice on the surface and the visco-elasticity of the surface cover, by observations of the evolution of surface waves. This also works in reverse so if the amount and type of oil or ice is known then the wave evolution and hence impact on drift and spreading of oil and ice can be estimated. Knowledge of the physical processes responsible for the spreading of oil in ice free and ice covered waters will help to develop technology for the remediation of the Arctic environment and reduction of environmental risks associated with oil contamination. To date, the main results involve: - verifying theoretical wave damping in the laboratory - development of wave sensors that can function in harsh arctic environments - testing theories for wave propagation in sea-ice with field data obtained in Svalbard - investigating wave-induced transport due to interactions with the surface waves and oil or ice - Design and Installation of a wave flume with wave maker in the cold laboratory at UNIS - Developing and testing new theories for wave damping in grease ice - Wave forecasting in operational models (WAM) when damping and drift of ice is included - Norwegian Meteorological Institute (MET) Several of these activities have been published in peer-reviewed journals. This project offers a unique combination of field and laboratory experiments, which is rare in modern scientific studies, and has the potential to gain a clearer understanding of the dominant hydrodynamic mechanisms associated with oil and/or ice surface covers than what previously exists. The project has now been finalised and by now there are 31 articles published in peer review journals and 16 talks are given at conferences.

-development of open source wave sensors for harsh environment -1 PhD and 3 MSc thesis -31 journal papers -new theories for wave damping in grease ice -damping and drift of ice is included in operational models by Norwegian Meteorological Institute

Investigation of physical processes responsible for the spreading of oil products in ice free and ice covered waters will help to develop technology for the remediation of Arctic environment and reduction of environmental risks in the Arctic associated wi th oil contamination. Surface waves propagating from clean waters into areas covered by a flexible surface cover, e.g. an oil slick or sea ice, will become (a) heavily damped due to frictional forces. The air-sea momentum fluxes that force the oceanic me an flows (b) depend on the waves and hence these will also be affected by the surface cover. In the wave damping process the waves exert a stress on the surface cover, hence (c) inducing mean flows that bring about changes in the surface cover properties, which will in turn impact on (a) the wave damping. Very few studies have considered the full coupling between the waves, the momentum fluxes, and the mean flow, and experimental evidence to validate components of such theories is lacking. The primary aim s of the proposed project are to determine -how different surface covers will damp waves, -how these surface covers impact on the air-sea fluxes, -how much of the lost wave momentum will lead to increased mean flow, -how the near surface turbulence and effective viscosity are affected by the covers. To answer these questions we will use theory, field measurements, and highly accurate laboratory experiments, in an attempt to close the gap between observations and theory. We will also identify and analy se the processes that are most relevant for improving our operational oil spill and sea ice drift models.