Research Document - 2006/039
An Overview of Meteorological, Sea Ice and Sea-Surface Temperature Conditions off Eastern Canada during 2005
By Petrie, B., R.G. Pettipas, and W.M. Petrie
A review of meteorological, sea ice and sea surface temperature conditions in the Northwest Atlantic in 2005 is presented. After 4 consecutive years of below normal values, the NAO index was above normal (~4.1 mb) in 2005. A positive NAO index implies stronger winds from the northwest, cooler air temperatures and enhanced heat loss from the ocean during winter over the Labrador Sea and partly over the Labrador and Newfoundland Shelf. However, except for January, the observed air temperatures were warmer than normal over the Labrador Sea; furthermore, the NCEP winter wind anomalies were generally towards the north in the Labrador Sea, opposite to our expectations for a positive NAO anomaly. Annual average air temperatures were above normal by 0.7 to 2.2°C over the Labrador Sea and Shelf, the Newfoundland Shelf, the Gulf of St. Lawrence and the Scotian Shelf; Gulf of Maine air temperatures were about 0.4°C below normal. The Newfoundland-Labrador ice coverage was the 5th lowest in 43 years and its duration was generally less than average. The Gulf of St. Lawrence ice coverage in 2005 was also less than normal ranking 15th of 43 years; the ice season was the 6th shortest in 43 years. Both the ice coverage, 13th least in 44 years, and its duration, 17th shortest in 44 years, on the Scotian Shelf were below normal. Only 11 icebergs reached the Grand Banks in 2005, considerably less than the 262 in 2004, and the lowest since 1985, when more accurate counts became available. It was also the 7th lowest count in 126 years. The analysis of satellite data indicates a north-south gradient of sea surface temperatures similar to the air temperature distribution. In 2005, there were positive annual SST anomalies from Bravo in the Labrador Sea to the central Scotian Shelf of 0.6 to 1.3°C, with the exception of the St. Lawrence Estuary which had an anomaly of nearly 0°C. The western Scotian Shelf, Lurcher Shoals, Bay of Fundy and Georges Bank were colder than normal with annual SST anomalies of ~0°C to -0.9°C.
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