Weathering processes in Arctic oil spills: Meso-scale experiments with different ice conditions

The knowledge regarding weathering processes in Arctic oil spills, and especially oil spills in ice, is limited. Experimental studies have been performed in laboratories, but only to a limited degree in the field. This paper presents results from a series of meso-scale field experiments performed on Svalbard, Norway, in 2005. The results from these field experiments performed to study oil behavior (evaporation, emulsification, spreading etc.) with different ice conditions (slush ice, 30% and 90% ice coverage) are presented in this paper. Several weathering properties are strongly influenced by the low temperature, reduced oil spreading and wave action caused by increased ice coverage. Reduced water uptake, viscosity, evaporation, and pour point in dense ice conditions extend the operational time window for several contingency methods compared to treatment of oil spills in open waters. For an oil spill in open ice, this could open up for dispersant treatment and in-situ burning even after an extended period of weathering.