Eddies southwest of the Denmark Strait

Numerous cold cyclonic eddies (20–40 km diameter) have been observed in satellite IR imagery (NOAA-11, Ch 3 and 4) along the edge of the East Greenland Shelf to the southwest of the Denmark Strait. The eddies move southwestward along the southeast edge of the East Greenland Current. The path of the eddies is coincident with the location of numerous deep current meter observations from previous surveys during which the strong pulses of overflow water (recorded speeds of over 150 cm s−1) had spectra peaked at periods of 1.5−2.5 days. It is suggested that the pulses are the signal observed from energetic, propagating cyclonic vortices extending up to the surface layer and formed by vortex stretching associated with the sinking of dense overflow water downstream from the sill of the Denmark Strait and along the shelf slope. The signature of the vortices at the sea surface appears in the IR imagery as a cold cyclonic eddy often exhibiting a pronounced spiral configuration. Because the entire water column in the slope region would be subjected to strong mixing by the vortices, considerable modification of not only the cold overflow water but also the intermediate and surface layers would occur.