Application of the POLARIS methodology to historic ice-class ship operations in freshwater lake ice

• Main Author: Tremblett, Adam Joseph
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2024
• Subjects: Sea ice
• Online Access: https://research.library.mun.ca/16494/; https://research.library.mun.ca/16494/1/Thesis.pdf

The primary objective of this work is to examine ship operations in freshwater versus sea ice in the context of evaluating appropriate regulatory guidelines, through analysis of historic data for the North American (Laurentian) Great Lakes region, a heavily trafficked freshwater waterway that is crucial for the functioning of Canada’s industrial heartland. The first goal of this analysis was to characterize expected ice conditions that could be found within the region through aggregating and sampling data from Canadian Ice Service ice charts over the 10-year study period, which includes the ice seasons from 2010 to 2019. This was followed by an analysis of ship traffic in the region during the same period through the use of historical archived AIS data. Lastly, the POLARIS methodology, an internationally accepted means of guiding ship operators in specific sea ice conditions, was applied to the historic ship operations described by the available AIS data to provide a comparison of historic operator decisions in lake ice to existing guidelines for operations in sea ice of similar thickness and concentration. The characterization of the regional ice conditions during the studied period was intended to provide additional context for the ship traffic analysis for comparison against typical local ice conditions along shipping routes. As existing reviewed literature previously indicated, this analysis clearly affirmed that there is significant year-to-year variability in the potential severity and duration of a given ice season in the Great Lakes. Results obtained from the analysis of historic ship traffic in the region and the application of the POLARIS methodology to this data provided valuable insights into the nature of current ship operations in ice in the Great Lakes. Overall, the trends observed suggest that current practices are well aligned with POLARIS guidelines for sea ice (89% of ice operations are in positive RIO values) and that risk mitigating measures currently used in the Great Lakes (such as ...