Buoy 4569 



Buoy 4569 was deployed near the 

 sea ice edge at 1500Z on 24 April 

 (114) at 51-58N, 50-48W. It re- 

 mained within the Ice Patrol opera- 

 tions area for 149 days, departing 

 on 20 September (263) (Figure B- 

 6a). The drogue sensor indicated 

 that the drogue disconnected on 29 

 September (272). The buoy was 

 still transmitting when it beached 

 near Cornwall, England on 2 August 

 1990. 



Buoy 4569 drifted southward in the 

 Labrador Current through the 

 Flemish Pass until 9 July (1 90) when 

 it reached the North Atlantic Current 

 and then travelled to the northeast. 

 Speeds in Flemish Pass ranged from 

 20 to 50 cm/s, and those between 

 southern Flemish Pass and day 1 90 

 were 36 to 50 cm/s. Temperatures 

 increased from -2°C to 9°C while the 

 buoy travelled southward in the La- 

 brador Current. After passing east 

 of Flemish Cap, buoy speeds in the 

 North Atlantic Cun'ent increased, 

 reaching up to 100 cm/s. Once in 

 the North Atlantic Current, tem- 

 peratures only varied between 1 2°C 

 and 16°C (Figure B-6b). The buoy 

 made an anticyclonic loop between 

 days 244 and 250. Speeds during 

 this period were 64 to 92 cm/s, and 

 temperatures were 12.6°C to 14.6°C. 



Buoy 4568 



Buoy 4568 was deployed at 1628Z 

 on 24 April (114) at 49-30N, 50- 

 40W. It remained within the Ice 

 Patrol operations area for 78 days, 

 departing on 11 July (192) (Figure 

 B-7a). The drogue sensor indicated 

 that the drogue disconnected on 1 

 August (222). The buoy was still 

 transmitting when it beached in Ire- 

 land on 11 February 1990. 



Page 66 



After being deployed over the shelf, 

 buoy 4568 drifted offshore until 

 reaching the Labrador Current. 

 Speeds over the shelf were less 

 than 15 cm/s, but gradually in- 

 creased starting on day 134. Speeds 

 through Flemish Pass increased 

 from 30 to 60 cm/s, and those south 

 of Flemish Pass (days 148 to 154) 

 decreased from 60 to 34 cm/s. It 

 followed a trajectory similar to that of 

 buoy 4569, but with higher speeds 

 (up to 60 cm/s) in the Labrador 

 Current (Figure B-7b). The tem- 

 perature record shows an increase 

 throughout the buoy's transit through 

 the Ice Patrol area. 



Buoy 4567 



Buoy 4567 was deployed at 1753Z 

 on 5 t^ay (125) at 47-1 ON, 46-59W. 

 It failed within the Ice Patrol area on 

 4 July (185) (Figure B-8a). The 

 drogue sensor indicated that the 

 drogue disconnected on 29 June 

 (180). 



Buoy 4567 was deployed in the 

 Flemish Pass and drifted southward 

 along the 1000-m contour until 16 

 May (136) when it turned offshore. 

 From deployment until day 139, 

 speeds were between 36 cm/s and 

 50 cm/s. It drifted southeastward 

 until being influenced by the North 

 Atlantic Current and turning to the 

 northeast. Between days 150 and 

 170 the buoy made a cyclonic loop 

 southwest of Flemish Cap before 

 resuming its journey to the north- 

 east. Speeds within the cyclonic 

 loop were less than 30 cm/s, but 

 increased upon exiting the loop, 

 reaching nearly 100 cm/s. The buoy 

 made another cyclonic loop between 

 days 175 and 184 with speeds 

 varying from 3 to 64 cm/s. 



The temperature record shows three 

 stages, each warmer than the pre- 



vious. The first stage lasts from 

 deployment until day 139, the sec- 

 ond from 146 to 161, and the third 

 from 172 until failure. 



Buoy 4570 



Buoy 4570 was deployed at 21 272 

 on 5 June ( 1 56) at 47-41 N , 47-01 W. 

 It remained within the Ice Patrol 

 operations area for 167 days, de- 

 parting on 19 November (323) 

 (Figure B-9a). The drogue sensor 

 indicated that the drogue was con- 

 nected until 27 November (331). 



The trajectory of buoy 4570 was 

 unusual. On day 164 the buoy 

 stopped travelling southward 

 through Flemish Pass and started 

 drifting eastward, passing just north 

 of Flemish Cap. Speeds across the 

 Cap (days 1 64 to 204) were slow (3 

 to 15 cm/s). The buoy trajectory to 

 the north and west of Flemish Cap 

 extends much further to the north 

 and west than would be expected. 

 The reason for this abnormal tra- 

 jectory is not known. The tempera- 

 ture record is not noteworthy, but 

 shows a general increase until day 

 218 and then a decrease. 



BUOY PERFORMANCE 



The performance of the nine opera- 

 tional buoys deployed during the 

 1989 season was adequate for IIP 

 use (Table B-2). The average num- 

 ber of days a buoy remained within 

 the IIP area was 94. Although 4537 

 failed within the IIP area, it provided 

 the longest period of information on 

 the area. 



The average number of days the 

 buoys transmitted data (as of 1 Sep- 

 tember 1990) was 271 , 304 if 9876 

 is excluded. The failure of 9876 

 could have been due to its deploy- 

 ment near sea ice since wind-driven 



