Summary of 

 Operations, 1989 



The 1989 IIP year (October 1, 

 1 988 - SeptemberSO, 1 989) marked 

 the 75th anniversary of the Interna- 

 tional Ice Patrol, which was estab- 

 lished Feboiary 7, 1914. HP's op- 

 erating area is delineated by 40°N - 

 52°N, 39°W - 57°W (Figure 1). 

 During 1 989, Coast Guard HC-1 30H 

 aircraft equipped with the AN/APS- 

 135 Side-Looking Airborne Radar 

 (SLAR) flew 44 ice reconnaissance 

 sorties, logging over 207 flight hours, 

 and Coast Guard HU-25B aircraft 

 equipped with the AN/APS-131 

 SLAR flew 27 reconnaissance 

 sorties, logging over 84 flight hours. 



Aircraft deployments were 

 made from January 26 to 31 and 

 February 16 to 25 to determine the 

 preseason iceberg distribution. 

 Based on the latter preseason de- 

 ployment, the 1989 IIP season was 

 opened on 1 March. From this date 

 until August 9, 1989, an aerial Ice- 

 berg Reconnaissance Detachment 

 (ICERECDET) operated from New- 

 foundland one week out of every 

 two. The IIP base of operations in 

 Newfoundland shifted from Gander to 

 St. John's during the 1989 season. The 

 seasonofficiallyclosedon July 28, 1989. 



Watchstanders at HP's Op- 

 erations Center in Groton, Con- 

 necticut analyze the iceberg sighting 

 information from the ICERECDETs, 

 along with sighting information from 

 commercial shipping and Atmo- 

 spheric Environment Service (AES) 

 of Canada sea ice/iceberg recon- 

 naissance flights. In 1989, IIP ac- 

 tively pursued obtaining iceberg 

 sighting information from additional 

 sources, such as the Canadian 

 Department of Defense, the Cana- 

 dian Department of Fisheries and 

 Oceans, and the commercial off- 

 shore fishing industry. 



The IIP Operations Center 

 received a total of 5,154 iceberg 

 sightings in 1989, compared to 

 35,129 in 1988. The decrease is 

 explained by cutbacks in AES 

 Canada's iceberg flights and cur- 

 tailment of offshore oil industry op- 

 erations. Only those iceberg 

 sightings made during the ice sea- 

 son and within HP's operations area 

 (40°N - 52°N, 39°W - 57°W) are 

 entered into the IIP iceberg drift pre- 

 diction computermodel(ICEPLOT). 

 1184 sightings were in HP's opera- 

 tions area in 1989, compared to 



1340 in 1988, and 1098 of these 

 were entered into HP's computer 

 model, compared to 1160 in 1988. 

 Watchstanders determine whether 

 each sighting is a resight of an ice- 

 berg llPalready has on ICEPLOTor 

 a new iceberg. Iceberg sightings 

 near the Newfoundland coast are 

 not entered into the computer model 

 due to a lack of ocean current in- 

 formation in these areas. 



HP's computer model con- 

 sists of one routine which predicts 

 the drift of each iceberg and another 

 which predicts the deterioration of 

 each. The drift prediction program 

 uses a historical current file which is 

 modified weekly using satellite- 

 tracked ocean drifting buoy data, 

 thus taking into account local, short- 

 term, current fluctuations. Murphy 

 and Anderson (1985) describe the 

 IIP drift model in more detail, along 

 with an evaluation of the model. 



The IIP iceberg deteriora- 

 tion program uses daily wind, sea 

 surface temperature, and wave 

 height information from the U.S. 

 Navy Fleet Numerical Oceanogra- 

 phy Center (FNOC) to melt the ice- 



Table 1 

 Sources of International Ice Patrol Iceberg Sightings By Size 



Percent 



Page 4 



