Figure 3. Model results from What-lfs drifting a growler. The left pariel displays the very large drifted with wirids and 

 currents and the right displays drift with winds only. The green symbols represents the modeled iceberg while the 

 brown represents actual Ice Island position. Note the growth of the error circle as time in the model elapses from 1 

 day to 3 days (5 NM, 10 NM, 20 NM). 



Conclusion 



The accuracy of BAPS modeled iceberg drift was analyzed through the use of multiple 

 What-If model runs drifting various icebergs. The modeled growler forced by winds alone best 

 represented actual Ice Island drift. Additionally, it is of note that a large portion of the modeled 

 results were within HP's 20 NM (radius) error circle for three-day-old icebergs. This fact lends 

 credence to the present error circle defaults used within BAPS. 



While this experiment is a good first attempt at producing some data for model ground- 

 truthing, it is not ideal given the drift characteristics of Ice Islands. For greater applicability, it 

 would be more ideal to track icebergs that are both more populous on the Grand Banks as well as 

 ones that BAPS is more suited to model. IIP has procured additional CALIBs for possible use 

 during the 2004 season and will attempt to place them on other, more typical targets. 



Historical Background 



Iceberg Marking and Tracking 



The need to track the drift of icebergs in the vicinity of the Grand Banks of Newfoundland 

 has existed for many years. IIP has transitioned from the most rudimentary method of iceberg 

 tracking to some of the most advanced during its 90-i- year lifespan. Initially, the ships assigned 

 to Ice Patrol drifted with the southern most iceberg(s) and reported their position, via radio, to 

 warn shipping interests in the area. Currently, the Ice Patrol is able to monitor the position of 

 icebergs with satellite positioning technology. Within the spectrum from drift tracking to satelhte 

 data, the Coast Guard has tried some interesting methods. 



The vessels of the Ice Patrol, each year, would search for icebergs, drift, and report 

 positions. As radio and navigation aid technology grew, ship-based reconnaissance data was used 

 to generate radio and text ice warnings. As reconnaissance ability grew with the application of 

 shipboard RADAR systems, the need to identify individual icebergs became necessary. Iceberg 

 marking with dye became a common procedure to facilitate consecutive identification of icebergs 

 and allow data on iceberg drift data to be collected (Figure 4). When the primary reconnaissance 



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