Conclusion 



Ice Patrol has now been using 

 satellite-tracked buoys for 5 years 

 to provide near real-time current 

 data for its iceberg drift prediction 

 model. This year is a good 

 example of the importance of this 

 near real time input. Without 

 weekly drifter data input, Ice Patrol 

 would have been using historical 

 mean currents to predict the mo- 

 tion of icebergs. Using historical 

 currents, icebergs in the Labrador 

 Current would have been drifted 

 south to 43°N. After modification 

 by drifter data to the current field, 

 icebergs in the Labrador Current 

 were drifted south to only 45°N. 

 The lack of drifter data could have 

 resulted in a 190 km drift error. 



The drogue sensor appears to be 

 providing more reliable data than 

 in the past. All five recovered 

 buoys (including those used 

 exclusively for the cruise), verified 

 the drogue sensor data, with four 

 attached and one disconnected 

 drogue. 



Ice Patrol plans to continue using 

 drifting buoys for near real-time 

 current data to update the histori- 

 cal current field. In areas of high 

 current variability, real-time data 

 are essential to accurate drift pre- 

 diction. 



Acknowledgements 



I am grateful to Dr. R. L. Pickett of the Naval Oceanographic 

 Research and Development Activity and Dr. Brian Petrie of Bedford 

 Institute of Oceanography for their comments on this manuscript. 



References 



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51 



