The Labrador Sea between Canada and Greenland is often referred to as a ‘lung of the deep ocean’ because it is one of only a handful of locations worldwide where oxygen from the atmosphere can enter the deepest layers of the ocean. The ability to sustain animal life in the deep ocean depends directly on this localized ‘deep breathing’. This process is driven by wintertime cooling at the sea surface, which makes oxygen-rich, near-surface waters denser and heavy enough to sink to depths of around 2 km in winter.
In a new study published in the journal Biogeosciences, a team of researchers from Dalhousie University in Halifax, Canada and the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany have now, for the first time, measured the flow of oxygen into the deep ocean interior that is carried by these deep currents. It is the oceanographic equivalent of measuring oxygen transport in our bodies through the main artery or aorta.
From one sea to many oceans
Jannes Koelling, lead author of the study, explains, “We wanted to know how much of the oxygen that is breathed in each winter actually makes it into the deep, fast-flowing currents that transport it across the globe.”
The deep mixing of oxygen in the central Labrador Sea is only a first step in the deep ocean’s life support system. Deep, boundary currents then distribute the oxygen to the rest of the Atlantic Ocean and beyond. This way, oxygen that is ‘inhaled’ in the Labrador Sea can support deep ocean life off Antarctica and even in the Pacific and Indian Oceans.
Read more at European Geosciences Union
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