Appendix C 



1987 International Ice Patrol Drifting Buoy Program 



Donald L Murphy 

 LT Neal B. Thayer, USCG 



INTRODUCTION 



This report documents the 

 operational portion of the 1987 

 drifting buoy program of the 

 International Ice Patrol. The 

 program, which began in 1976, 

 supports Ice Patrol operations 

 and research. 



Eighteen separate buoy deploy- 

 ments were made in 1987. Of 

 these, nine were launched from 

 Ice Patrol reconnaissance aircraft 

 and the data used primarily for 

 operational purposes (Summy 

 and Anderson, 1983 and Summy, 

 1982). The remainder were de- 

 ployments from U.S. Coast Guard 

 vessels conducting Ice Patrol 

 research cmises. Most of the 

 latter were drift tracks of short 

 duration, with the buoy being 

 recovered at the end of each 

 experiment. Two of the aircraft- 

 deployed buoys were launched 

 by Ice Patrol off northern Labra- 

 dor as part of a Canadian Atmos- 

 pheric Environment Service 

 (AES) test of their iceBerg 

 Analysis and Prediction System 

 (BAPS). 



Ice Patrol sponsored two oceano- 

 graphic research cmises in 1987. 

 The first, (IIP 87-1) from 27 April 

 to 20 May, was conducted at)oard 

 USCGC BITTERSWEET (WLB 

 389). The objective of IIP 87-1 

 was to investigate the ability of 

 HP's side-looking airt)orne radar 

 (SLAR) to detect warm-core 

 eddies. Six separate buoy 

 deployments were made during 

 this research. Of these, two 

 buoys were not recovered at the 



end of the experiment, and their 

 data were used for operational 

 purposes. The buoy tracks 

 during the cruise period are 

 discussed in Appendix D of this 

 Bulletin. 



The second 1987 Ice Patrol 

 research cruise (IIP 87-2) was an 

 iceberg drift and deterioration 

 study conducted aboard USCGC 

 TAMAROA (WMEC 166). from 8 

 June to 27 June. TAMAROA 

 deployed three buoys, all of which 

 were recovered at the end of the 

 experiment. The results of this 

 cruise are discussed in Appendix 



With the exception of the buoys 

 deployed solely for research. Ice 

 Patrol enters all of its buoy data 

 onto the Global Telecommunica- 

 tions System (GTS). Although 

 Ice Patrol is directly interested in 

 sea surface temperature and 

 position data only when the buoys 

 are within its operations area, the 

 buoys frequently leave the area 

 and move eastward across the 

 North Atlantic. Tracking the 

 buoys eastward serves the dual 

 purpose of providing useful 

 oceanographic data to the world 

 oceanographic community and 

 providing the opportunity to 

 recover a buoy when it beaches 

 or crosses the path of a ship 

 willing to recover it. Approxi- 

 mately one buoy per year is 

 recovered and returned to Ice 

 Patrol for reuse. 



All of the buoys used in 1987 had 

 a 3 meter long spar hull with a 1 

 meter diameter flotation collar. 



Each buoy was equipped with a 2 

 by 10 meter window-shade 

 drogue attached to the buoy with 

 a 50 meter tether of 1/2" (1 .3 cm) 

 nylon. The center of the drogue 

 was at 58 m. In addition, each 

 buoy had a temperature sensor 

 mounted approximately 1 m 

 below the waterline, a drogue 

 tension monitor, and a battery 

 voltage monitor. The sea surface 

 temperature is accurate to 

 approximately 1°C. 



The drogue sensor data should 

 be viewed with some caution. 

 Although recent experience 

 (Anderson, 1986) suggests that 

 the sensor reliably reports drogue 

 status, it sometimes fails. In 

 some cases the buoy's drift track 

 can provide evidence of drogue 

 separation. For example, an 

 abrupt increase in variability with 

 a period of several days might 

 suggest that the drogue has 

 detached and the buoy drift is 

 being affected by the wind and 

 wind-driven currents. However, 

 short of relocating and recovering 

 the buoy, there is no way to know 

 with certainty that the drogue 

 remained attached for the period 

 of interest. 



The data from the buoys are 

 acquired and processed by 

 Service ARGOS. Ice Patrol 

 queries and stores the data files 

 once daily. 



Table C-1 summarizes the 18 

 buoy deployments in 1987. This 

 table reflects the status of all the 

 buoys as of 31 December 1987. 



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