Ice and Environmental Conditions 



Introduction 



Icebergs returned in large numbers 

 to the transatlantic shipping lanes near 

 Newfoundland in 2000, creating dangerous 

 navigational conditions for mariners. 

 Although the air temperatures in the region 

 were generally warmer than normal and 

 the sea ice cover less extensive and 

 thinner than normal, International Ice Patrol 

 counted 843 icebergs that passed south of 

 48°N latitude, the boundary below which 

 icebergs are considered a threat to 

 transatlantic shipping. This active iceberg 

 season followed one of the lightest in HP's 

 history, with only 22 icebergs counted in 

 1999. This section describes evolution of 

 the 2000 iceberg season and the 

 environmental conditions it accompanied. 



For record keeping purposes, the 

 IIP ice year extends from October through 

 September. The following month-by-month 

 narrative of the progress of the 2000 ice 

 season begins as sea ice began forming 

 along the Labrador coast in mid-November 

 1999, and concludes in July 2000 as the 

 last vestiges of the sea ice departed the 

 Labrador coast. The narrative draws from 

 several sources, including the Seasonal 

 Summary for Eastern Canadian Waters, 

 Winter 1999-2000 (Canadian Ice Service, 

 2000a); sea ice analyses (pages 22-30) 

 provided by the Canadian Ice Service and 

 the National Ice Center; the Integrated 

 Global Ocean Services System Products 

 sea surface temperature anomaly (Climate 

 Data Library, International Research 

 Institute for climate prediction at Lamont- 

 Doherty Earth Observatory of Columbia 

 University); and finally, summaries of 

 iceberg data collected by IIP and CIS. The 

 Biweekly Iceberg Charts section (pages 

 31-43) documents the LAKI on the first and 

 15"^ of each month during the season. 



Comparing the 1999-2000 sea ice 

 and iceberg observations to the historical 

 record emphasizes the departures from 

 normal and gives a greater appreciation for 

 the variability of the ice distribution in the 

 western North Atlantic. For sea ice. Sea 

 Ice Climatic Atlas, East Coast of Canada, 

 1971-2000 (Canadian Ice Service, 2000b) 

 provides a 30-year median of ice 

 concentration at seven-day intervals for the 

 period from 26 November through 16 July. 

 Viekman and Baumer (1995) present an 

 iceberg limits climatology from mid-March 

 to 30 July based on 21 years of Ice Patrol 

 observations from 1975 through 1995. 

 They provide the extreme, median, and 

 minimum extent of the LAKI for the period. 

 Finally, the average number of icebergs 

 estimated to have drifted south of 48°N for 

 each month was calculated using 101 

 years (1900 through 2000) of IIP records. 



The pre-season sea ice forecast 

 (Canadian Ice Service, 1999), which was 

 issued in early December, predicted the 

 following: 



• normal freeze-up, 



• ice edge movement into the 

 Strait of Belle Isle during late 

 December, 



• sea ice reaching the Avalon 

 Peninsula the last week 



of February, 



• maximum extent of the sea ice at 

 the end of March, and 



• retreat at a slower pace than 

 usual due to predicted lower than 

 normal spring air temperatures. 



November - December 1999 



The fall and early winter freeze-up in 

 1999 began normally. By the end of 

 November, new ice had formed in the bays 

 and inlets along the Labrador coast north 



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