Project overview

The UK OSNAP array. Image courtesy of UK-OSNAP. ©

OSNAP overview

UK-OSNAP is funded by the Natural Environment Research Council. The project is led by the National Oceanography Centre (NOC) with partners in the University of Liverpool, the University of Oxford and the Scottish Association for Marine Science (SAMS). It is a part of international OSNAP, which is led by USA and includes 10 further partner groups in Canada, France, Germany, the Netherlands and China. The project runs for five years from October 2013 and involves fieldwork at sea and model studies.

OSNAP will provide a continuous record of the full-water column, trans-basin fluxes of heat, mass and freshwater in the subpolar North Atlantic Ocean.

The OSNAP observing system consists of two legs: one extending from southern Labrador to the southwestern tip of Greenland across the mouth of the Labrador Sea (OSNAP West), and the second from the southeastern tip of Greenland to Scotland (OSNAP East). The observing system also includes subsurface floats (OSNAP Floats) in order to trace the pathways of overflow waters in the basin and to assess the connectivity of currents crossing the OSNAP line.

The location of the OSNAP East and West legs melds with a number of long-term observational efforts in the North Atlantic: the Canadian repeat AR7W program in the Labrador Sea; the German Labrador Sea western boundary array at 53°N; the global Ocean Observatories Initiative node to be placed in the southwestern Irminger Sea; the repeat A1E/AR7E hydrographic sections across the Irminger and Iceland basins; the Ellett line in the Rockall region. Importantly, this proposed observing system, in conjunction with the RAPID/MOCHA array at 26ºN and the EU THOR/NACLIM program, will provide a comprehensive measure of the Atlantic Meridional Overturning Circulation (AMOC) and provide a means to evaluate intergyre connectivity in the North Atlantic.