TOD #2632 was deployed as part 

 of an iceberg drift and 

 deterioration study and it 

 remained in the survey area until 

 28 July (210). The drogue of 

 TOD #2632 remained above the 

 middle of the thermocline (35- 

 40m) for the period of 1 7-28 July 

 (199-210). The drift of TOD 

 #2632 within the survey area can 

 be almost totally explained by the 

 wind driven current. 



During both phases of the cruise, 

 wind speed and direction 

 measurements were taken 

 aboard HORNBEAI^/i every hour. 

 The anemometer was 

 approximately 1 5m above the 

 water. The FNOC [Marine Layer 

 Wind product used by IIP 

 represents winds 1 9.5m above 

 the sea surface. Twelve hour 

 average measurements for 

 OOOOZ and 1200Z {+1- 6 hours) 



were determined and compared 

 to the analysis wind products 

 received from FNOC. It should be 

 noted that a comparison is being 

 made between point source 

 winds (HORNBEAM) and spatially 

 averaged winds (FNOC). The 

 data show that wind velocity 

 computed by FNOC was 

 consistently higher than that 

 measured (Table B-3). The 

 FNOC winds are used in the 



Geostrophic Current 

 Along Track of TOD 2633 



\ I \\\\\\\\\\\\ 



Drift Vectors of TOD 2633 



Xx w 



^ I \ \ 



\ X \ ^ \ / / / 



Calculated 

 Wind Driven Current . 



^ 



^\ \ \ 



\ \ 



.zx 



Drift Vectors of TOD 2632 



I I I I I 



10 20 30 40 cm/sec Geostrophlc Current Along Track of TOD 2632 * * * * * *_ 



7 July 



11 July 



16 July 



21 July 



27 July 



-" ' 1 



1 August 



TOD Drift, Measured Geostrophic Current, and 

 Calculated Wind Driven Current 



Figure B-7. The geostrophic current shown for each TOD track was calculated from data obtained1-11 July 1984. 

 The TOD drift vectors are a 24-hour average centered around 1200 GMT of each day. The wind driver} current was 

 calculated based on McNally (1981) and used 1.5% of the wind speed directed 3CF to the right of downwind. Observed 

 winds from the HORNBEAM were used in the calculations when available (7-11 and 16-21 July). FNOC winds were used 

 for the remaining calculations. The * indicates an area where accurate geostrophic currents could not be calculated. 



63 



