Historical Analysis of Ice Conditions for Risk Assessment

Abstract The analysis of historical satellite data, both radar and optical, areuseful for understanding the nature of ice conditions in Arctic regions andunderstanding the risk they pose for exploration and development. Archivesatellite data are available at no cost and can be analyzed to assess theseverity and variability of iceberg concentrations and their behavior. National ice centres have been providing charts of sea ice conditions, whichcan be analyzed to understand probabilities of encountering ice of variousconcentrations and the lengths of the open water season. The outputs ofthese analyses are useful for understanding the risk of operating in Arcticregions and for developing an ice management plan. Introduction Satellite radar and optical imagery are essential tools for understandingsea ice and iceberg conditions in frontier Arctic and sub-Arctic regions. Satellite synthetic aperture radar (SAR) imagery can be collected day or night, are relatively independent of environmental conditions, can be collectedthrough fog and cloud cover and provide information over remote areas at noadditional cost. There is a substantial archive of low resolution imageryavailable and there is a growing number of sensors available for newacquisitions. Optical imagery, when available, are excellent forproviding detailed information on ice features such as sea ice ridges andiceberg sizes. Low resolution optical data are collected continuously, medium resolution data is available close to shore and high resolution imagescan be acquired from a large number of sensors. Historic satellite data are used to develop an understanding of the severityand variability of ice conditions in an area. This information serves asan input for the design of structures and selection of vessels that can beutilized in an area as well for development of an ice management plan anddefining the operational window. New image acquisitions are an important part of the detection component ofan operational ice management plan. Surveillance in certain marginal icezones, such as the Grand Banks, do not rely on satellite imagery since they areclose to shore and reconnaissance can be carried out almost exclusively usingplatform radar and vessel and aerial surveillance. However, the costs ofthis approach grow in remote areas and satellite SAR data have been used inaddition to platform radar to support operations in new Arctic explorationregions.