Overturning in the Subpolar North Atlantic Program (OSNAP)

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A second trans-basin array, deployed in the summer of 2014 further north than RAPID, running from the Labrador shelf to the southern tip of Greenland (OSNAP West) and from southeastern Greenland across to the Scottish shelf (OSNAP East). It combines around sixty moorings with gliders and floats. Its first results, published in 2019, overturned the textbook picture by showing that the eastern section — the Irminger and Iceland basins — accounts for the great majority of subpolar overturning and its variability, and the Labrador Sea for very little. It is a good example of a long-held mechanism surviving a direct measurement in outline while losing its assumed geography.