On a recent flight to the US my plane passed over the southern tip of Greenland. A huge swirling formation was clearly visible just off the southernmost point (see photo, top right, taken from 38,000 feet). It appeared to be in the water rather than forming from cloud. Can anyone provide more information? Would this cause any difficulties to a small boat sailing across it?
鈥� Sea ice forms along the east coast of Greenland during winter. In the spring and summer this breaks up and drifts south on the East Greenland current.
Advertisement
鈥淕reenland sea ice breaks up in spring and summer and drifts south on the East Greenland current鈥�
My photo shows the outer margin of an ice pack off the south coast of eastern Greenland in June 2006. The dense ice pack along the coast forms the white background. The white speckles in the foreground are individual ice masses that have broken off the ice pack, with the brighter clumps showing ice masses that are packed close together. A nearby trawler was about the same size as the largest ice masses.
Your correspondent鈥檚 photo shows similar floating ice that has drifted beyond the southern tip of Greenland. The sea surface in the bright white areas is completely covered in broken ice. Mottled areas are partly covered by varying amounts of ice, while the dark grey areas are largely ice-free with the odd isolated berg. These are significantly larger than the bulk of the ice fragments in the light grey areas.
The looped structure marks a large eddy, or gyre, in the ocean current. It is a nice example of an oceanic feature that is normally not visible. As it鈥檚 found just south of Greenland, it may result from interaction of the with the open water at the entrance to the Davis Strait, between Greenland and Canada. The local distribution of ice masses seems complex and the feature is likely to be transient.
The ribbons of dense ice accumulation would seem, to a non-sailor, to be a serious hazard to a small boat, particularly if they are mobile and visibility is poor.
Ian Platten, Welwyn Garden City, Hertfordshire, UK
鈥� This satellite image shows an area of drift ice off the Greenland coast. The patterns occur as the ice is moved by wind and ocean currents. This was taken on 30 March 2013 and shows a section of Greenland鈥檚 east coast and the location of drift ice and fast ice along the coast.
Bernard Burton, Wokingham, Berkshire, UK