Atmospheric conditions associated with oceanic convection in the south-east Labrador Sea

• Published in: Geophysical Research Letters
• Main Authors: Sproson, David A. J., Renfrew, Ian A., Heywood, Karen J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: Greenland; Labrador Sea; North Atlantic; North Atlantic oscillation
• Online Access: https://ueaeprints.uea.ac.uk/id/eprint/24833/; https://ueaeprints.uea.ac.uk/id/eprint/24833/1/sproson_etal_forcing_labsea_2007GL032971_GRL_2008.pdf; https://doi.org/10.1029/2007GL032971

It has been speculated that low-level reverse tip-jets, caused by the interaction of synoptic-scale atmospheric flow and Greenland, are an important mechanism for forcing open ocean convection in the south-east Labrador Sea. Here float data and meteorological reanalysis fields from the winter of 1996/1997, in combination with a simple mixed-layer ocean model, are used to show that, although relatively deep ocean convection did occur during this winter, the primary forcing mechanism was cold-air outbreaks from the Labrador coast rather than the smaller scale reverse tip-jets. During this winter, the North Atlantic Oscillation (NAO) was in a weak positive phase. Similar treatments of the winters of 1994/1995 (strong, positive NAO) and 1995/1996 (strong, negative NAO) suggest that the result is robust regardless of the state of the NAO.