Figure D-2. Iceberg and TOD trajectories for Case I (1983) 



Data Description 



The data used in this study 

 were collected from 1 983 

 through 1 985. All of the cases 

 were drifts of short duration, with 

 a maximum drift period of 4.5 

 days. In all fourcases, the drifting 

 icetjerg was ctose to at least one 

 freely-drifting TIROS 

 Oceanographic Drifter (TOD), 

 from which local currents were 

 determined. The TOD hull was a 

 3m spar and was fitted with a 2m x 

 1 0m window-shade drogue at the 

 end of a tether. The drogue 

 depths presented here refer to 

 the depth of the center of the 

 drogue. The TOD's were tracked 

 by the NOAA/TIROS series 

 satellites and the data provided to 

 IIP by Sen/ice ARGOS, with a 

 position accuracy well within 

 500m (Bessis, 1981). 



In three of the cases (11,111, 

 and IV), a surface vessel near the 

 iceberg was collecting local wind 

 data. The data for each case are 

 discussed separately. The 

 numbers in parentheses after 

 each date are Julian year dates, 

 that is, dates numbered 

 sequentially from 1 January. 



Case I 



This case consists of a 2.5- 

 day drift of a large tabular iceberg 

 wrth a TIROS Arctic Drifter (TAD) 

 aboard. The TAD, which is 

 essentially a TOD with different 

 packaging, had been deployed 

 onto the iceberg on 27 March 

 1983 (86) by IIP, in cooperation 

 with the U. S. Coast Guard 

 Research and Development 

 Center (R&DC). 



70 



47' 



ICEBERG (A ▲) 



TOD 38m{o— — 0) 



46 



o 133/ooz 



• 134/boz 



/* 135/ ooz 



48' 



47' 



The test period began at 

 1600Zon12May1983(132) 

 when a TOD, drogued at 38m, 

 was air-deployed from a HC-1 30 

 aircraft at a location approximately 

 1 km from the iceberg, which at 

 the time was nroving southward in 

 the Labrador Current (Figure D- 

 2). 



The test period ended on 

 1 5 May (1 35) shortly t>efore the 

 iceberg grounded for a 4-day 

 period. The iceberg was last 



sighted with the TAD aboard on 

 21 May (141) by Mobil Oil 

 Company, Canada (Anderson, 

 1983). On this date the iceberg 

 was still classified as large, with 

 estimated dimensions of 

 1 50mx 1 1 0mx30m. During the 

 test period, the maximum 

 separation tjetween the TAD 

 (icet)erg) and the TOD was less 

 than 25km. No on-scene wind 

 data were available. 



