Based on a unique dataset collected during a research cruise to the Irminger Sea in April 2015, a new paper reveals a strong link between atmospheric forcing, deep convection, ocean ventilation and anthropogenic carbon sequestration.The Irminger Sea, a small ocean basin between Greenland and Iceland, is known for its harsh and extreme weather conditions during winter. Research cruises that  take measurements in the subpolar North Atlantic almost exclusively do so in summer, although the area is particularly interesting in the convectively active winter season.