Abstract
The overflow of cold, dense water from the Nordic seas, across the Greenland–Scotland ridge1 and into the Atlantic Ocean is the main source for the deep water of the North Atlantic Ocean2. This flow also helps drive the inflow of warm, saline surface water into the Nordic seas1. The Faroe Bank channel is the deepest path across the ridge, and the deep flow through this channel accounts for about one-third of the total overflow1,2. Previous work has demonstrated that the overflow has become warmer and less saline3,4 over time. Here we show, using direct measurements and historical hydrographic data, that the volume flux of the Faroe Bank channel overflow has also decreased. Estimating the volume flux conservatively, we find a decrease by at least 20 per cent relative to 1950. If this reduction in deep flow from the Nordic seas is not compensated by increased flow from other sources, it implies a weakened global thermohaline circulation and reduced inflow of Atlantic water to the Nordic seas.
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Acknowledgements
The ‘Nordic WOCE’ project was funded by the Nordic Environmental Research Programme for 1993–97, and by Nordic national research councils. The ‘VEINS’ project was supported by the MAST IV Programme of the European Community.
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Hansen, B., Turrell, W. & Østerhus, S. Decreasing overflow from the Nordic seas into the Atlantic Ocean through the Faroe Bank channel since 1950. Nature 411, 927–930 (2001). https://doi.org/10.1038/35082034
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DOI: https://doi.org/10.1038/35082034
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