Buoy 4566 



Buoy 4566 (Figure B-5) was 

 deployed at 1351Z on 1 August 

 (214)at59-01N, 61-27W. After89 

 days of drift, 4566 was recovered 

 by SIR JOHN FRANKLIN on 27 

 October (301). The drogue sensor 

 indicated several short periods 

 when the drogue appeared to be 

 detached. These periods oc- 

 curred when the buoy was in 

 relatively shallow water (<100 m). 

 It is likely that the drogue was 

 resting on the bottom during these 

 periods. Most of the drogue 

 sensor data accurately showed 

 the drogue was attached for the 

 entire drift period. 



Buoy 4566 was deployed at the 

 same time and location as a mini- 

 drifter that was provided by AES 

 (Buoy 3435). The intent of the 

 concurrent deployment was to 

 compare the performance and drift 

 of the two buoy types. Unfortu- 

 nately, the mini-drifter failed after 

 about twelve hours in the water. 



The movement of 4566 during its 

 88 day drift was generally south- 

 eastward. It is complicated for two 

 reasons. The first is the complex 

 flow along the Labrador Coast due 

 to the convoluted bottom topogra- 

 phy. Second, the standard buoy 

 configuration has a 50 m drogue 

 tether, which means that the 

 bottom of the drogue extends to a 

 depth of over 60 m. Several of the 

 banl<s along the coast have 

 shallower depths. In particular, 

 during the period from 26 August 

 to 6 September (239-250) 4566 

 was grounded on a pinnacle east 

 of Nain, Labrador. There is no 

 clear evidence for further ground- 

 ing, but there is one short period 

 of sluggish nriotion when 4566 was 

 on Hamilton Bank (12 October 

 286). 



72 



B'oOY ^5G6 

 1988 



18 

 16 

 14 

 12 

 10 

 8 

 G 

 4 

 2 

 

 -2 



tn 



21G 



80 p 

 B0 - 

 40 - 

 20 - 

 



II 1 1 1 1 1 1 1 



231 



24B 



2G1 

 YEHR-DRY 



27G 



291 



3 -20 V 



3 -40 - 

 -G0 - 



-80_ 



216 



I I I I I I I I I I I I IJ I I I I I I I M M I I n I I I , I I I I 11 I M I I I I I I I I I I I I I I I I I I I I I III 



231 



246 



26 1 

 YERR-DRY 



276 



29: 



-80_ 



216 



I I I I I 1 1 1 I 1 1 1 I I 1 1 Mini I I I I I 1 1 I I I I 1 1 IJ III! 



231 



246 



261 

 YERR-DRY 



276 



291 



Figure B-5a. Time history of sea surface temperature, U, and V ve- 

 locity components (filtered) for 4566. 



The most vigorous motion during 



4566's drift came during a sixteen moving across Makkovik and 

 day period (17 September to 20 Harrision Banks. At times 4566's 

 October, 261 -276) when it was speed exceeded 50 cm/s. 



