International Polar Year 2007–2008 - WMO

system. Some of these constraints are reasonably wellknown.
In general terms, we know that when the Arctic
Oscillation is in its negative phase, the atmospheric
circulation tends to accumulate freshwater in the
Amerasian Basin and decrease it in the Eurasian Basin
(vice versa during the positive phase). This tends to
increase the freshwater export by creating larger
upper-layer thicknesses in the passages of the CAA
compared with Fram Strait. Although the freshwater
outflow leaving the CAA is normally sufficiently
distinct in density to pass south along the west side of
Baffin Bay or over-ride the fresh tongue passing north
in the opposite sense along the W Greenland Margin,
this is not necessarily an unvarying situation.
As Rudels (2009) has recently proposed on the basis
of the present Θ-S structure to the west of Greenland,
the freshwater transport in the W Greenland Current
may well modulate or control that outflow. By this
novel theoretical idea, an increased melting of
the Greenland ice-cap may, in the outlook period,
lower the density at large in E Baffin Bay sufficiently
to alter the path or slow the southward flow of the
CAA freshwater outflow. An increased freshwater
production from Greenland also does not appear
unlikely. On the contrary, it now appears demonstrable
that warming of the seas around Greenland has been
a cause of a recent acceleration in the four main outlet
glaciers that drain the interior. Thus in addition to the
main task of establishing an optimal observing system
capable of capturing the changing character of the
freshwater outflow through the CAA and Baffin Bay/
Davis Strait at modest cost over years to decades (Fig.
3.2-8), a second task of establishing a sound theoretical
footing for the disruptive effects of an increasing
ice-melt from Greenland has arisen. Craig Lee (UW),
Simon Prinsenberg and Humfrey Melling (DFO) and
Bert Rudels (Univ. Helsinki) will investigate. Fiamma
Straneo (WHOI) and Kelly Faulkner (OSU) will continue
their fjord-scale assessment of the role of the warming
ocean in accelerating the ice-flux from Greenland.
Designing an optimal ocean observing
system for the IPY legacy phase
If we are to achieve more for (presumably) less
funding in the post-IPY phase, it will be by close
coordination and focus. This is not a new realization.
The thrust of this Report is no different to the primary
conclusion of the AON Design and Implementation
(ADI) Project Plan following its task force meeting in
November 2009, that ‘…there is now an urgent need
for coordination, consolidation and optimization of
the existing observing system elements as well as for
development of a broader strategy that includes more
detailed design studies to enhance and sustain the
Fig. 3.2-8. A potential
means of achieving
a difficult but
climatically-important
measurement
at modest cost.
Through cooperation
with the Canadian
Defense Research
Development
Corporation (DRDC),
it is planned to use
an acoustic/cable/
satellite link to provide
oceanographic data
from Barrow Strait in
real time.
(Image: Simon Princenberg BIO)
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