On the relationship between dense water formation and the “Meridional Overturning Cell” in the North Atlantic Ocean. Deep-Sea Res

• Main Authors: C. Mauritzen, S. Ha Kkinen
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1999
• Subjects: Arctic; Barents Sea; Greenland; Norwegian Sea; Greenland-Scotland Ridge; Labrador Sea; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.621.5345; http://met.no/Forskning/Vare_forskere/Cecilie_Mauritzen/filestore/Mauritzen_Hakkinen_DSR1999.pdf

We analyze the three-dimensional structure of the Meridional Overturning Cell (MOC) in a numerical model of the North Atlantic and Arctic Oceans. The MOC is found to consist of several downward branches: some associated with dense water formation driven by surface buoyancy forcing (Labrador Sea, northern Norwegian Sea and Barents Sea), and some asso-ciated with interior mixing processes in the model (most notably entrainment of thermocline waters into the dense overßows at the Greenland—Scotland Ridge). Two experiments with altered surface buoyancy conditions are performed, both resulting in a change in the dense water formation rate in the Labrador Sea. A change of the same sign is observed in the strength of the MOC (and thus in the meridional heat ßux); however, the change is less (20—50%) than would be expected from the change in the dense water formation rate. The MOC and the rate of dense water formation at higher latitudes seem not to be tightly linked on the decadal time scale. Instead, signiÞcant changes in the volume of water masses may take place. Taking this phenomenon into account may improve the interpretation of the chain of events that consti-tutes a climate oscillation, whether it be observed in models or in nature. ( 1999 Elsevier Science Ltd. All rights reserved. 1.