The influence of sea-ice conditions on crude oil spill behaviour

Sea-ice conditions during a crude oil spill govern oil behaviour and the rate of weathering processes. This study utilized data from past mesocosm experiments conducted at the Sea-ice Environmental Research Facility and compared the sea-ice temperature, salinity, and chemical composition of light crude oil under three sea-ice conditions. An oil spill under discontinuous pack ice showed a decrease in ice thickness with an increase in oil concentration, as well as the highest photooxidation of organosulfur compounds amongst all experiments. An oil spill under a continuous ice volume demonstrated a decrease of sea-ice bulk salinity with an increase in crude oil concentration. Also, oil exhibited the lowest evaporation, along with the highest dissolution and carbonylation rates. An oil spill before ice formation demonstrated the reduction of sea-ice thickness and bulk salinity in contaminated ice. The oil in this case exhibited the highest evaporation and photooxidation rates. Tested oil-in-ice scenarios produced quantitative differences in sea-ice properties and crude oil composition.