Ice Island Deterioration in the Canadian Arctic: Rates, Patterns and Model Evaluation

Abstract

Knowledge regarding the deterioration processes of large tabular icebergs, known as ice islands, is limited within the Canadian Arctic. This study analyzed ice island deterioration through two aspects: 1) horizontal (areal) and 2) vertical (surface melt or ‘ablation’). Satellite images were digitized to monitor areal dimensions, classify deterioration modes and correlate deterioration rates with environmental variables. The rates of deterioration were different between the Eastern and Western Canadian Arctic regions possibly due to differences in air temperature and sea ice concentration. Validation of operational surface ablation models was also carried out with in-situ microclimate measurements. The Canadian Ice Service iceberg model under-predicted surface ablation by 68%, while a more complete energy-balance model developed for ice islands improved output accuracy (7.5% under-prediction). These analyses will provide useful knowledge regarding the deterioration process of ice islands to offshore stakeholders for mitigation of risks associated with ice island hazards to offshore operations.