Research Document - 2015/053
Physical Oceanographic Conditions on the Newfoundland and Labrador Shelf during 2014
By Colbourne, E., Holden, J., Senciall, D., Bailey, W., Craig, J. and S. Snook
Abstract
An overview of physical oceanographic conditions in the Newfoundland and Labrador Region during 2014 is presented as part of the Atlantic Zone Monitoring Program (AZMP). The North Atlantic Oscillation (NAO) index, an indicator of the direction and intensity of the winter wind field patterns over the North Atlantic, returned to a positive phase in 2014 that was associated with strong arctic air outflow in the northwest Atlantic during the winter months and consequently, lower than normal winter air temperatures. Sea ice extent increased substantially during the winter of 2014 with the first positive anomaly (higher-than-normal extent) observed in 16 years. Annual sea-surface temperatures (SST) based on infrared satellite imagery remained above normal in most areas across the Newfoundland and Labrador (NL) Shelves in 2014, however, values have declined from record-highs observed in 2012. The annual bottom (176 m) water temperature at the inshore monitoring station (Station 27) was below normal in 2014 by‑0.6 standard deviations (SD), a significant decrease from the record high in 2011. The cold-intermediate layer (CIL; volume of < 0°C) in 2014 was at its highest level since 1985 on the Grand Bank during the spring and the highest since 1991 off eastern Newfoundland during the summer. Spring bottom temperatures in 3Ps remained above normal by about +0.5 SD but were slightly below normal on the Grand Banks by - 0.3 SD. Fall bottom temperatures in 2J and 3K decreased from 2 and 2.7 SD above normal in 2011 to 0.7 and 0.3 above normal in 2014, respectively, a significant decrease in the past three years. As a result the area of bottom habitat covered by water < 2°C increased to near-normal values in 2014 during both spring and fall. A standardized climate index derived from 28 meteorological, ice and ocean temperature and salinity time series declined for the 3rd consecutive year, reaching the 11th lowest in 65 years the lowest since 1994 and the first negative index since 1995.
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