TIROS Oceanographic Drifters 



Seven TIROS Oceanographic Drifters (TODs) 

 were deployed during the 1983 IIP season 

 (Table B-1). All of the TODs were deployed with 

 window shade drogues attached to the TOD by 

 a 30m tether. Each TOD was equipped with a 

 sea surface temperature sensor, a drogue ten- 

 sion sensor, and a battery voltage monitor. The 

 position (determined by Doppler shift) and sen- 

 sor information from each buoy was obtained 

 from Service ARGOS. On 22 September, IIP 

 stopped collecting data from Service ARGOS 

 due to the relocation of IIP to Groton, CT. All 

 drift tracks of the seven TODs are shown in 

 Figure B-2. The velocity distributions are given 

 in Figure B-4. 



TOD #2633 was deployed on 5 May 1983 in 

 the Avalon Channel at 48°00'N,52°15'W (Figure 

 B-2). The buoy proceeded in a southward direc- 

 tion until becoming caught in an eddy near 

 47°00'N, 52°35'W. TOD #2633 was brought 

 ashore by a fisherman on 14 June. The 

 parachute was still attached to TOD #2633 

 when it was recovered. It is not known how the 

 drift information obtained from TOD #2633 was 

 affected by the unreleased parachute. 



TOD #2634 was deployed from USCGC 

 NORTHWIND north of the Flemish Cap at 

 48°40'N, 45°30'W. TOD #2634 drifted slowly 

 south around the east side of the Flemish Cap 

 averaging 14 cm/sec for its first 2 months of 

 deployment. About 2 June, TOD #2634 was 

 caught in the North Atlantic Current. From 2 

 June until 28 June, the average velocity in- 

 creased to 73 cm/sec. During 7-9 June, TOD 

 #2634 was caught in a meander near 46°45'N, 

 42°30'W before heading north in the North 

 Atlantic current. After leaving another meander 

 near 50°30'N, 42°20'W on 28 June, TOD #2634 

 began its journey across the Atlantic. There is 

 no physical evidence in the Canadian METOC 

 sea surface temperature (SST) charts to sup- 

 port the existence of either of the above 

 meanders (Figure B-3). 



TOD #2630 was deployed on 21 February 

 1983 at the top of the Grand Banks at 48°39'N, 

 49°50'W. It moved southward paralleling the 

 bathymetry of the Banks at an average velocity 

 of 32 cm/sec until crossing 45°N on 18 March. 

 On 12 March the sensor data indicated that the 

 drogue had become disconnected from the 

 buoy. TOD #2630 entered the North Atlantic 

 Current on 21 March. It then moved off to the 

 northeast, averaging 38 cm/sec, until it was 

 caught in a meander near 46°15'N, 42°30'W on 

 about 7 April. TOD #2630 drifted north at 48 

 cm/sec and was caught in a second meander 

 near 49°30'N, 43°00W before heading east 

 across the North Atlantic. 



TOD #2613 was deployed in the entrance to 

 the Flemish Pass at 48°39'N, 49°00'W on 21 

 February. TOD #2613 proceeded southward 

 paralleling the topography at an average veloci- 

 ty of 27 cm/sec. It entered the North Atlantic 

 current on about 19 March and moved in a 

 northeastward direction until 2 April near 

 45°30'N, 46°00'W. Between 2 and 22 April, TOD 

 #2613 was caught in an eddy. The Canadian 

 METOC SST charts for that period supports the 

 existence of an eddy in the area. TOD #2613 

 drifted at an average velocity of 35 cm/sec 

 while trapped in the eddy. After release from 

 the eddy, it moved off at about 75 cm/sec in a 

 northeastward direction until leaving the IIP 

 region. 



TOD #2636 was deployed on 8 April 1983 

 north of Flemish Cap at 48°30'N, 45°00'W. TOD 

 #2636 drifted slowly, averaging about 12 

 cm/sec, in an eastward direction until 24 April. 

 On that date, it entered the North Atlantic Cur- 

 rent and was carried first southeastward and 

 then northward at an average velocity of 51 

 cm/sec until 1 May. On 1 May, TOD #2636 was 

 caught in an eddy near 49°00'N, 42°45'W. With 

 the exception of two short time periods, it 

 moved with the clockwise circulation of the ed- 

 dy until the last position was received on 4 

 August. For the three months TOD #2636 was 

 trapped in this eddy, it moved at an average 

 velocity of 44 cm/sec. The Canadian METOC 

 SST charts show the existence of a warm core 

 eddy near this region for the above time period 

 (Figure B-3). 



TOD #2610 was deployed 8 April 1983 in the 

 Flemish Pass at 47°00'N, 47°10'W. TOD #2610 

 drifted south roughly paralleling the 

 bathymetry of the Grand Banks until it was 

 caught in an eddy near 45°10'N, 48°25'W on 14 

 April. It travelled northward at 16 cm/sec before 

 being released from the eddy on 9 May. TOD 

 #2610 entered the North Atlantic current on 16 

 May and four days later was caught in an eddy 

 near 45°20'N, 46°45'W that carried it southward 

 and then southwestward at an average velocity 

 of 33 cm/sec. It was released from the eddy on 

 about 3 July and travelled northeastward at 40 

 cm/sec with the meanders of the North Atlantic 

 current. The sensor data indicated that the 

 drogue of TOD #2610 was lost on 22 August. 

 The existence of the three eddies was con- 

 firmed by the Canadian METOC SST charts 

 (Figure B-3). 



TOD #2632 was deployed on 12 May 1983 in 

 the Flemish Pass at 46°50'N, 47°18'W. TOD 

 #2632 drifted southward paralleling the 

 bathymetry until it entered the North Atlantic 

 Current. TOD #2632 was caught in the same ed- 



54 



