Seagliders have been deployed in Davis Strait in 2005
As expected at the outset of this effort, the strait
has proven to be a difficult environment for gliders due to remoteness and
ice. In addition to ice related difficulties, the remoteness of the strait
means that even when more typical problems occur in open water, recovery
operations are difficult. This was the case with SG018 in 2005 (probable pump
failure) and SG112 in 2007 (satellite phone failure).
SG109 made the first successful under ice section across the strait
in December 2006. From the ice edge on the eastern side of the strait the
vehicle navigated to a waypoint 50 km west under ice and back east again
over the course of one week. Unfortunately the vehicle was lost shortly
after this achievement. The failure mode is unknown.
SG108 and SG113 were launched in September 2008 during the yearly array servicing
cruise. Both functioned successfully to the start of the icing period in mid-November.
On November 15, SG108 went under the ice on the eastern side of the strait for the
first of two successful cross-strait transects. Due to strong currents along the
Baffin slope the glider was pushed south off the line survey line in both cases and had
to work its way back to the northeast to the eastern end of the line. The return trip
followed the ice edge in some cases and thus the glider was in and out of ice cover
during this period. The movie below indicates glider position and ice coverage based
on Canadian Ice Service maps beginning November 5 (when the first map for the area was produced)
and ending February 25, 2009 when the glider was recovered by the Danish Navy after successfully
transiting from the survey region to a recovery point off Nuuk, Greenland. Red positions indicate
GPS navigation fixes (and thus periods or dive when there was open water), blue indicates
RAFOS acoustic fixes (periods or dive when the glider was under ice and unable to come to the
surface) and green are interpolated positions indicating that the glider was under ice and
did not have a recent acoustic navigation solution.