Conductivity, temperature, and depth (CTD) measurements made north of Svalbard, centered around 83¿N, 10¿E, show regions in which the surface waters are supercooled to a depth of about 8 m. At other locations, warm Atlantic waters advected into the area by the West Spitzbergen current are melting the sea ice. The resulting large horizontal salinity gradients cause intrusive layering with layers at depth sometimes being below their surface freezing point. Supercooling is explained in terms of the pressure dependence of freezing temperature and the existence of ice keels well below the surface. It is noted that the potential heat sink for surface freezing provided by supercooling can be of the same order as that available from heat loss to the atmosphere. At the same time an equivalent amount of ice is being melted off the keels thus constituting an ''ice pump''. |