Convective mixing in the central Irminger Sea: 2002-2010

A near-continuous time series of 8 years of daily hydrographic profiles, recorded between fall 2002 and summer 2010 by moorings located in the central Irminger Sea, is presented. This record shows that convective mixing down to 400 m depth occurs in most winters. Under favorable conditions, convective mixing is seen to reach much deeper. During the cold winter of 2007–2008 mixed layers reached depths of 1 km. In the subsequent, more moderate winter of 2008–2009, a stronger preconditioning of the Irminger Gyre led to mixed layers down to 800 m depth. The convectively formed waters in the Irminger Sea are more saline and warmer than those formed in the Labrador Sea, but potential vorticity is reduced to 0.7 10