A new iceberg drift, deterioration and calving model has been under development at the Canadian Ice Service (CIS). The model includes several new features including the utilization of detailed environmental forcing input, and a robust implicit numerical solution method. In particular, the vertical distribution of water current is incorporated in calculations of water drag force on the iceberg keel. The model is also the first to include treatment of calving, prediction of calved ice piece size distribution and deterioration, as well as the drift of calved pieces.
This paper gives a description of the drift model formulation, and verification tests that include comparisons of model predictions with field observations. Additionally, the paper presents the outcome of a parametric study aimed at examining the sensitivity of iceberg drift to input parameters and environmental forcing. Tests examined the role of water and air drag coefficients, water current, wind waves and the waterline length of the iceberg. A number of scenarios of input water current, and wind drag force were also considered.
The Canadian Ice Service (CIS) has been developing a new operational model to forecast iceberg drift and deterioration over the Grand Banks region. Offshore developments in that region have led to increasing demands for reliable iceberg drift forecast, and new forecast output concerning for example calving and small ice mass populations. The new CIS model deals with the dynamics and drift of icebergs, as well as the deterioration of the icebergs due to various thermal processes and calving. The model also keeps track of calving events, size distributions of the calved bergy bits, and their melt and drift. The calving and deterioration aspects of the model have been presented in the papers of Savage et al. (2000) and (2001), and Savage (2002).