Slantwise Convection in the Irminger Sea

The subpolar North Atlantic is a site of significant carbon dioxide, oxygen, and heat exchange with the atmosphere. This exchange, which regulates transient climate change prevents large-scale hypoxia throughout Atlantic, thought to be mediated by vertical mixing in ocean's surface mixed layer. Here we present observational evidence that waters deeper than conventionally defined layer are affected directly atmospheric forcing this region. When northerly winds blow along Irminger Sea's western boundary current, Ekman response pushes denser water over lighter water, potentially triggering slantwise convection. We estimate down-front wind four times stronger air–sea flux buoyancy can mix several depth. Slantwise convection not included most ocean models, likely limits their ability accurately represent mass transformations deep ventilation.