Nares Strait is a narrow arctic waterway bounded by the east coast of Ellesmere Island (Canadian) and the western coast of Greenland (Danish). The strait is frozen throughout the winter season but opens in the summer and is a major pathway for sea ice flushing out of the High Arctic. The strait is also a conduit for icebergs and ice islands which calve off Greenland's northwestern glaciers.
This year (and the last two years) have been quite unusual. The ice in Nares Strait usually consolidates around the beginning of February, and normally you would not see an elongated warm signature extending right up the strait as we are seeing this winter on the Infrared imagery. The ice in the Strait then usually breaks up in the last week of July.
The normal (1971-2000) winter situation is shown on this map:Median of Ice Concentration March 01 1971-2000, where black is 10/10 consolidated ice coverage and where red is mobile 9-10/10 ice coverage.
Nares Strait did not consolidate in 2007, allowing for a continuous flow of thick multi-year ice from the Arctic Ocean down to Baffin Bay. It did consolidate in 2008, but further north than normal (with the ice bridge starting at the north end of Kane Basin instead of in Smith Sound). This year, 2009, it hasn't consolidated yet (again). So far (unlike 2007) an ice bridge HAS formed, preventing a flow of Arctic multi-year sea ice into the Strait. But (unlike 2008) it has formed at the far north end of Robeson Channel.
Because of the location of the ice bridge at the north end of Robeson Channel (instead of in the normal position in Smith Sound) and because of the prevailing northerly winds through the Strait, a polynya has formed extending the length of Nares Strait. The winds continuously push newly formed ice southwards, away from the ice bridge, keeping the ice at the north end of the Strait permanently broken and thin. Normally this polynya (the North Open Water or NOW polynya) forms at Smith Sound, with open water first appearing in mid-May to early-June (see: Median of Ice Concentration June 11 1971-2000).
Break-up of Northern Nares Strait Ice Arch
July 06 2009 1800 UTC
Ice Arch Collapse - 13 July 2009
Ice Arch Collapse - 06 to 15 July 2009
Ice Arch Collapse - 19 July 2009
Ice Arch Collapse - 23 July 2009
Ice Arch Collapse - 03 August 2009
- Date Modified: