A sea change in our view of overturning in the subpolar North Atlantic

  • M. S. Lozier, F. Li, S. Bacon, F. Bahr, A. S. Bower, S. A. Cunningham, M. F. de Jong, L. de Steur, B. deYoung, J. Fischer, S. F. Gary, B. J. W. Greenan, N. P. Holliday, A. Houk, L. Houpert, M. E. Inall, W. E. Johns, H. L. Johnson, C. Johnson, J. Karstensen, G. Koman, I. A. Le Bras, X. Lin, N. Mackay, D. P. Marshall, H. Mercier, M. Oltmanns, R. S. Pickart, A. L. Ramsey, D. Rayner, F. Straneo, V. Thierry, D. J. Torres, R. G. Williams, C. Wilson, J. Yang, I. Yashayaev, J. Zhao
  • Science, January 2019, American Association for the Advancement of Science
  • DOI: 10.1126/science.aau6592

Overturning in the subpolar North Atlantic

What is it about?

The North Atlantic overturning involves cold waters sinking at high latitudes and spreading away from the sinking regions, and being replaced by warmer waters moving northward from the tropical Atlantic. The strength of this overturning is usually associated with the deep water formation in the Labrador Sea. This OSNAP field programme has measured the strength of the overturning and the transport of heat and freshwater. 21 months of measurements have revealed a surprising result, the strength of the overturning is mainly associated with circulations from Greenland to Scotland, rather than across the Labrador Sea.

Why is it important?

The overturning redistributes heat over the North Atlantic and affects the overlying atmosphere by altering its surface temperature and moisture. If we are to understand how the overturning varies in time and its link to climate, we need to understand how the overturning is controlled. This field programme sets out a view that changes in the ocean circulation between Greenland and Scotland are the key to understanding its temporal variability.


Professor Richard G Williams
University of Liverpool Department of Earth Ocean and Ecological Sciences

This programme was led by Susan Lozier and involved a major international collaboration between the USA, Uk, Canada, France, Germany, Netherlands and China.

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The following have contributed to this page: Professor Richard G Williams