SST Anomoly may 2006 



75W 7W/ E5W mi 55W SOW 4SW 4«l/ 



35* W» J V 



1 



0.5 



-0.5 



-1 



-1.5 



-2 



-:.5 

 -3 



-4 

 -5 

 -6 



Figure 8. Sea surface temperature anomaly for 

 May 2006 in degrees C. (Plot courtesy of 

 National Oceanic and Atmospheric 

 Administration / National Weather Survey) 



Discussion 



No icebergs passed south of 48°N in 

 2006 placing it in a tie with 1966 - "the year 

 with no icebergs". In some respects, 2006 

 was a less severe iceberg year than 1966, in 

 some not. For example, in 1966 many 

 growlers drifted southward amidst pack ice 

 to 47°30'N, 52°30'W and several growlers 

 moved as far south as 46°55'N, 52°15'W 

 (International Ice Patrol, 1966). In 2006 the 

 southernmost position of glacial ice was an 

 iceberg seen on 28 March at 49°0rN, 

 52°59'W - over 120 nm farther north. On 

 the other hand, the early summer iceberg 

 population along the Labrador coast was 

 greater in 2006 than it was in 1966. The 

 1966 population south of Cape Chidley 

 (about 60°30 , N) was 297 on 7 June, while in 

 2006 there were over twice that number 

 south of 56°N at the end of June. This 

 suggests that more icebergs reached the 

 Labrador coast in 2006 than in 1966. 



There are more similarities than 

 differences between the two record-setting 

 iceberg years, particularly in the 



accompanying environmental conditions. In 

 both years: 



• Newfoundland and Labrador 

 experienced much-warmer-than 

 normal air temperatures. In the case 

 of 2006, numerous records were set 

 for warmth in Labrador. 



• The pack ice arrived late, departed 

 early, and was less extensive than 

 normal. 



• The sea surface temperatures were 

 warmer than normal in the region, 

 particularly in the central Labrador 

 Sea. 



• Several storms brought strong on- 

 shore winds to the Labrador coast in 

 the preceding December and January. 



These common factors are consistent with 

 many of the previous light iceberg years 

 (Murphy, 1999). They are also consistent 

 with the negative phase of the North Atlantic 

 Oscillation (NAO). The winter 2006 

 (December 2005 through March 2006) NAO 

 Index (NAOI) was -1.09 (Hurrell, 2007), 

 which was calculated using the difference of 

 normalized sea level pressure between 

 Lisbon, Portugal and Stykkisholmur/ 

 Reykjavik. Iceland. 



The NAO, the dominant mode of winter 

 atmospheric variability in the North Atlantic, 

 fluctuates between positive and negative 

 phases. The positive phase is associated with 

 meteorological conditions that favor the 

 movement of icebergs into the shipping 

 lanes. These include strong and persistent 

 northwest winds along the Labrador coast, 

 which bring colder-than-normal air 

 temperatures and greater-than-normal sea-ice 

 extent. In addition, the persistent northwest 

 winds promote southward iceberg movement. 

 Warmer-than-normal conditions and less 

 extensive sea-ice off the Labrador coast are 

 associated with the negative NAO phase. The 

 -1.09 NAOI value in 2006 was strongly 

 negative, which is consistent with the 



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