Appendix C 



Limit-Setting Iceberg Report for 1997 Season 



CDR Stephen Slelbeck and MST2 L. Scott Howell 



Introduction 



International Ice Patrol's mission is to 

 identify the Limits of All Known Ice (LAKI) and 

 to transmit this information to mariners at sea. 

 During the ice season, the key element of IIP 

 operations is to conduct reconnaissance pa- 

 trols to determine the location of icebergs that 

 establish the LAKI. 



The LAKI is based on all known iceberg and 

 sea ice information and represents the extent 

 of iceberg danger in the vicinity of the Grand 

 Banks of Newfoundland. From Newfound- 

 land, the line marks the southwestern, south- 

 ern and southeastern limits of the iceberg re- 

 gion, and ends at an intersection point with 

 latitude 52°N. Over the last twenty years, at 

 its extremes, the LAKI has extended in the 

 northwestern Atlantic Ocean as far south as 

 latitude 39°N and in the east to longitude 

 37°W. 



Limit setting icebergs are those icebergs that 

 form the vertices of the LAKI. International 

 Ice Patrol in recent years has collected data 

 to learn more about these important icebergs. 

 Analysis of this data has indicated the large 

 relative contribution of sightings from IIP re- 

 connaissance flights in this critical area near 

 the limits. 



The information pertaining to the limit setting 

 icebergs is important as a measure of effec- 

 tiveness of HP's surveillance efforts in locat- 

 ing the iceberg hazard. It is HP's goal to con- 

 tinuously improve its mission performance by 

 effectively locating the icebergs that consti- 

 tute the LAKI and accurately provide this in- 

 formation to ships to enable them to avoid 

 encountering icebergs. 



Data Collection 



Limit setting icebergs were categorized 

 as eastern, southern and western by the side 

 of the LAKI "polygon" where they occurred. 

 For the majority of cases, the three catego- 

 ries of icebergs were distinct populations. The 

 few exceptions were when icebergs drifted 

 from the southern limit to the eastern limit 

 and, in those instances, the iceberg's desig- 

 nation was changed accordingly. 



Data on the limit setting icebergs were gath- 

 ered daily from the output of the Iceberg Data 

 Management and Prediction System (DMPS). 

 Icebergs were recruited as limit setters either 

 from the 1200Z Ice bulletin list of "icebergs 

 not in area of many bergs" or from iceberg 

 sightings by the various source at or near the 

 LAKI. Each day, the icebergs in the limit set- 

 ter database checked to ascertain any resights 

 or deletions these changes were recorded. 

 The following information was determined for 

 each of the designated limit setting icebergs: 



1 . DMPS iceberg number 



2. Days on plot in DMPS model. 



3. Days as a limit setting iceberg. 



4. Source of sighting when entered in 

 limit setter database, and any sub- 

 sequent resighting source. 



5. Location on LAKI - (West, South, 

 East) 



6. Method of deletion 



Collection of data on a given limit setting ice- 

 berg ended when it was deleted from DMPS 

 by standard IIP criteria. There are two ways 



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