International Polar Year 2007–2008 - WMO

during 1999. Nevertheless, four years later in 2003, a
large array of sub-sea instruments was installed from
USCG Healy across Kennedy Channel, much further
north in Nares Strait where icebergs are less common.
Most of these instruments were retrieved using CCGS
Henry Larsen in 2006. The array for IPY was complete
by late August 2007. In July 2007, two moorings were
placed from CCGS Louis S St-Laurent in Bellot Strait, the
narrowest and only unexplored choke point for CAT;
one of these moorings carried a variety of sensors for
biological parameters (chlorophyll, turbidity, dissolved
gases, acoustic backscatter and marine vocalization).
In early August 2007, moorings in western Lancaster
Sound was recovered and replaced from CCGS des
Groseilliers. By the end of that month, the array at the
southern end of Kennedy Channel (Nares Strait) had
been re-established from CCGS Henry Larsen and the
long-standing installations in Cardigan Strait had
been recovered and re-deployed. The high logistic
cost of working in Nares Strait precluded the recovery
and re-deployment of moorings in this remote area in
2008, but the full array was recovered in August 2009.
With this recovery, one of the hardest observational
tasks in oceanography was successfully accomplished.
The ‘point’ of making these measurements remains;
carrying the main freshwater flux between the Arctic
Ocean and North Atlantic west of Greenland, the
passageway-flows of the Canadian Arctic Archipelago
carry significant inputs to the Atlantic MOC and are
thus of importance to climate. The task now will be
one of maintaining these difficult arrays over years to
decades, but at lesser cost.
A major advance in monitoring ocean fluxes
through Davis Strait; the first autonomous subice
glider profiles. The Davis Strait carries all of the
exchanges of mass, heat and freshwater between the
Arctic and the Northwest Atlantic west of Greenland
and thus acts as a vital monitor of Arctic and subarctic
change. Beginning in autumn 2004, Craig Lee (U.
Washington) has devised a system of moorings and
extended-endurance (9-12 months) autonomous
gliders capable of monitoring oceanic exchanges
across the full width of the Strait. The major milestone
was achieved in December 2006 with the first successful
operation of a glider beneath the ice-covered western
Davis Strait; a single SeaGlider successfully navigated
from the ice-free eastern Strait westward to 59°W,
shifting to fully autonomous behaviour, avoiding
the surface and continuing its westward transit
after encountering the ice-edge. Significantly, all
aspects of the ice-capable glider system functioned
properly, including acoustic navigation, ice sensing
and autonomous decision making. The entire section
was conducted without human intervention, with the
glider making its own decisions and surfacing to report
its data after navigating back to the ice-free eastern
side of Davis Strait. By returning observations to within
a few meters of the ice-ocean interface and at roughly
5 km horizontal resolution, the technique successfully
resolved the south-flowing, surface-trapped arctic
outflow from CAA. Unfortunately, a hydraulic failure
and faulty Iridium modems and Iridium/ GPS antennas
caused the temporary suspension of under-ice
SeaGlider operations for 2007–2008. Nevertheless,
in 2009, operations resumed with a second major
milestone: an autonomous glider, engineered for
extended operation in ice-covered environments,
completed a six-month mission sampling for a total
of 51 days under the ice-cover of the western Davis
Strait during which the glider traversed over 800 km
while collecting profiles that extended to within a few
meters of the ice-ocean interface.
Applying iAOOS: Linking
environmental- and ecosystem-
changes in Northern Seas
Much of the point of expanding the observing and
modeling effort in northern seas during IPY has had to
do with the ecosystem and its changes. Many of the
projects that were funded for IPY had the ecosystem
as their prime focus. Nevertheless, it is clear that after
two years of effort, many of these studies will be
at an early stage so it will take some care if we are to
do these projects justice. Here, we adopt the approach
of trying first to identify those aspects of environmental
variability that are most likely to drive change
through the ecosystem of northern seas, ‘ecosystem:
temperature’ and ‘ecosystem: ice’ relations seem to
be the most fundamental. We then describe some of
the hypothetical linkages between the ecosystem and
its environment that have been put forward in studies
of longer duration than IPY. Finally, we seek out cases
where these hypotheses are being tested, altered,
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