Sea ice involved in pulses of cold, fresh sea water in the North Atlantic

What is it about?

Global warming has its largest effects in the Arctic where enhanced melting of sea-ice will send increased cold meltwater southwards into the North Atlantic with possible effects on climate in Europe and North America. Here we describe an intermediate source of Atlantic cold fresh water derived from melting of the Odden ice, a variable body of new sea-ice which appeared in the far north Atlantic basin in three periods during the 1960s, 1970s, and 1980s. Odden ice formed over deep water in response to freezing winter winds together with enhanced transport of ice from the Arctic Sea and was additional to the normal East Greenland sea-ice near the coast. Three subsequent periods of Odden melting in summer released large pulses of cold fresh water and ice which entered the Labrador Sea basin 2,000 km away and facilitated three corresponding periods of unprecedented sea-ice formation in the following winter. We identify Odden and Labrador Sea meltwater as the sources of the three Great Salinity Anomalies that spread cold low-salt water around the northwest Atlantic in the 1970s, 1980s, and 1990s and may have affected North Atlantic climate.

Featured Image

Photo by Joseph Barrientos on Unsplash

Photo by Joseph Barrientos on Unsplash

Why is it important?

Sea surface temperature patterns across the North Atlantic can affect the climate of Europe. Our new work has identified a new way that cold and fresh water is moved around the coast of Greenland. Improved understanding can help to better interpret how ocean and atmospheric circulations are changing and their effects on global climate change.

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