Forecasting Ice Strength

The report summarizes the conclusions of studies addressing the potential for incorporating ice strength in ice forecasts. Recommendations based on those studies are provided. Previous work has examined the formulas developed by Timco and Johnston (2002) to characterize ice strength. The first objective was to develop a product that provides shipping operators of expected ice strength. The second was exploring the feasibility and effectiveness of using the strength formulas as input to forecast models. Inspection of available ice strength records and estimates show that the decay of strength takes place over approximately 3 month period. Changes in strength over a few days are usually insignificant. Therefore, for the first objective, it recommended that a forecast of ice strength is best issued using a stand-alone program. Ice dynamics models would not provide any added value, and should not be used to issue ice strength forecasts. For the second objective, references are made to initial work characterizing the effect of varying the strength on ice drift and deformation. Incorporating ice strength in ice dynamics models, however, would require more investigations consisting of parametric studies to determine the impact on the forecasts, and validation against field observations.Peer reviewed: NoNRC publication: Ye