Length of Ice Seasons Since 

 1995 



50 100 



Days 



150 200 



Figure 6. Ice season lengths since 1995. 



merged into the BAPS model is not used 

 because IIP does not necessarily merge all 

 reported targets. Sightings of targets 

 outside HP's area of responsibility and 

 coastal icebergs are usually not merged as 

 they represent little threat to transatlantic 

 shipping. Thus, the total number of 

 merged targets is not necessarily an 

 objective and unbiased measurement from 

 year to year. 



Icebergs South of 48''N Since 

 1995 



500 1000 



Icebergs 



1500 



Figure 7 Icebergs south of 48 N since 1995, 

 excluding growlers, bergy bits, and radar targets. 



Season length is intertwined with 

 the number of icebergs south of 48°N, as 

 Commander, International Ice Patrol 

 considers the iceberg population when 

 determining when to open or close the 

 season. Various authors have discussed 

 the appropriate measurement for ice 

 season severity (Alfultis, 1987; Trivers, 

 1994; Marko, e\ al., 1994). Comparing 

 2000 to the past five years and measuring 

 the statistics against historical standards in 

 various papers, 2000 was moderate in 



terms of season length and extreme in 

 terms of the number of icebergs south of 

 48"N. A moderate season length is 

 defined as between 105 and 180 days 

 (Trivers, 1994). Extreme for icebergs is 

 defined as greater than 600 icebergs south 

 of 48'N (Trivers, 1994, Marko, et al., 

 1994). 



Number of Icebergs South of 



48"N by Month of 843 Total 



Icebergs 



350 

 300 

 250 

 200 • 

 150 

 100 

 50 

 



^ . .□ Drifted 



^M HH 1 ■ Detected | 



MAR 



APR 



MAY 



JUN 



JUL 



Figure 8. Icebergs south of 48 N in 2000, 

 excluding growlers, bergy bits, and radar 

 targets. 



During the ice season, IIP prepares 

 and distributes ice bulletins at OOOOZ and 

 1200Z daily to warn mariners of the 

 southwestern, southern, and southeastern 

 LAKI. U. S. Coast Guard Communications 

 Area Master Station Atlantic/NMF and 

 Canadian Coast Guard Marine 

 Communications and Traffic Service St. 

 John'sA/ON are the primary radio stations 

 responsible for the dissemination of ice 

 bulletins. In addition, ice bulletins and 

 safety broadcasts are delivered over the 

 INMARSAT-C SafetyNET via the Atlantic 

 East and West satellites. Another 

 transmitting station for the bulletins is the 

 Marine Communications and Traffic 

 Services St. AnthonyA/CM. IIP also 

 prepares an ice chart depicting the 1200Z 

 limit of all known ice for broadcast at 

 1600Z and 1810Z daily. U. S. Coast 

 Guard Communications Area Master 

 Station Atlantic/NMF and the National 

 Weather Service assist with the 

 transmission of the ice chart. On the 

 European side of the Atlantic, Radio 



