DISCUSSION 



Figure C-4 presents 

 the modified IIP mean cur- 

 rent data base as it now ex- 

 ists. The digital data are avail- 

 able on electronic medium 

 upon request. This data base 

 represents our best knowl- 

 edge of the mean currents in 

 the IIP operations area during 

 the iceberg season, but 

 suffers from the well known 

 problems of mean represen- 

 tations of oceanic circulation. 

 It does not describe well the 

 circulation in areas with sig- 

 nificant temporal variability. 

 The temporal variability of the 

 currents in portions of the Ice 

 Patrol operations area is well 

 known (Petrie and Isenor, 

 1985), so great caution must 

 be exercised when using this 

 data base for drift prediction. 

 Nonetheless, the mean repre- 

 sentation of the offshore 

 branch of the Labrador Cur- 

 rent in and south of Flemish 

 Pass is well represented in 

 the data base. This area, 

 known as iceberg alley, is of 

 greatest interest to IIP be- 

 cause it moves icebergs south- 

 ward into the trans-Atlantic 

 shipping lanes. The drifting 

 buoy data clearly support 

 the existence of core speeds 

 lower than the previously 

 used values of 1 00 cm/s. 



Page 84 



Ice Patrol plans to 

 update the data base periodi- 

 cally. As new drifting buoy 

 data become available, they 

 will be incorporated into the 

 data base, most likely every 

 two years. Wori<ing with the 

 drifting buoy archive had the 

 side benefit of identifying 

 areas in the Ice Patrol 

 operations area where 

 additional buoys should be 

 deployed. In particular, the 

 inshore branch of the Labra- 

 dor Current and the northeast 

 Newfoundland Shelf are 

 poorly represented in the data 

 set. Operations permitting, 

 Ice Patrol plans to deploy ad- 

 ditional buoys in these areas. 



