Figure 13. AXBT drop locations. 



during the 2003 season. IIP dropped 30 

 AXBT probes and collected data from 25 of 

 the drops for a failure rate of 16.6%. 

 Figure 14 describes the development of 

 HP's AXBT program since 1999\ The 

 marked reduction in AXBT drops during 

 2003 can be attributed to a change in 

 AXBT drop policy that occurred following 

 the 2002 season in an attempt to eliminate 

 drops that interfered with the flight plan or 

 othenwise reduced the effectiveness of the 

 reconnaissance. 



AXBT information was coded into a 

 standard format and shared with the 



140 

 120 

 100 



CQ 



80 

 60 

 40 

 20 



1999 2000 2001 2002 2003 

 i^i^AXBTs • Failure rate 



Figure 14. AXBT drops and failure rate (1999-2003). 



' 1999 is used as the base year for these data because of 

 the implementation of a new AXBT receiver system 

 during that year. Software upgrades, planned for 

 completion in 2004, are expected to further reduce 

 failures. 



Canadian Maritime Atlantic Command 

 Meteorological and Oceanographic Center, 

 HP's supplier of AXBT probes. Data was 

 also sent to the U. S. Naval Fleet 

 Numerical Meteorological and 



Oceanographic Center where it was quality 

 controlled and redistributed via 

 oceanographic products. 



Satellite-tracked drifting buoys, 

 popularly known as WOCE buoys, were 

 drogued at a depth of 15 or 50 meters and 

 provided near real-time ocean current 

 information. For operational use by IIP, 

 WOCE buoys were deployed primarily in 

 the inshore and offshore branches of the 

 Labrador Current. The historical current 

 database used by HP's computer model 

 was modified weekly using information 

 from these drifting buoys. The 2003 

 iceberg season proved especially 

 challenging in terms of current variability at 

 the southern end of the Grand Banks and 

 in the vicinity of the Flemish Cap, 

 demonstrating HP's requirement for this 

 valuable information. 



During the 2003 season, IIP 

 deployed ten satellite-tracked drifting 

 buoys, four from reconnaissance aircraft 

 and six from volunteer ships. Figure 15 

 displays composite drift tracks for the 

 buoys deployed in 2003. Figure 16 

 displays the shift from aircraft deployments 

 to ship deployments over the last few 

 seasons. Ship deployments are less costly 

 and less traumatic to the buoy than aircraft 

 deployments. IIP intends to maintain the 

 capability to deploy buoys from aircraft, 

 primarily for early season deployments to 

 the north and isolated required 

 deployments during the season. No buoy 

 recoveries were planned or attempted in 

 2003. Detailed drifter information is 

 provided in HP's 2003 WOCE Buoy Drift 

 Track Atlas (available from IIP upon 

 request). 



13 



