A HIGH RESOLUTION
MOORING ARRAY FOR IPY
|
The Bering Strait is the only Pacific Entrance into the Arctic
Ocean. It is a ~ 50m deep, ~ 85km wide channel, divided in two by
the two Diomede Islands. Waters flowing through the Bering Strait
are a major source of nutrients for Arctic ecosystems, and an important
source of freshwater both for the Arctic and (after some years) the
North Atlantic. The Bering Strait throughflow is believed to
influence the Atlantic Overturning Circulation and thus, even though
the Bering Strait throughflow is small, changes in its volume or
properties may have impacts on world climate.
Since 1990, we have measured the Bering Strait throughflow, mostly on
the eastern side which is in US waters. Since 2004, a Russian-US
collaboration has been measuring in both sides of the Strait.
Now, in this 2-year IPY project, Russian and US scientists will work
together to get the best ever resolution of the physical and biological
features of the Bering Strait.
Schematic map of the
Bering Strait region
|
The main focus of
our work is an 8 mooring array (right), which
will be deployed in the Strait year-round from Autumn 2007 to Autumn
2009. Each mooring will carry instruments to meaure water
velocity at
all depths and temperature and salinity of the water at at least 2
levels. The Bering Strait region is ice-covered in winter, and
keels
from the floating sea-ice can damage equipment. Our moorings will
use
novel instrumentation (ISCATS) designed at the University of Washington
to survive encounters with sea ice. These instruments will be
knocked
down by sea-ice, or by very strong currents, but will bounce back when
the ice/current is gone. This 8 mooring array (with 3
moorings in the
Russian channel, 4 moorings in the US channel, and 1 mooring at a
possible "climate" site to the north) is designed to describe the
physics of the water flow and thus improve our interpretation of older
data.
Schematic of the Bering
Strait region and the High Resolution Mooring Arrary. Land is
marked in grey. Depth contours (blue/green) are at 5m intervals
from IBCAO bathymetry. Dots mark mooring sites (red = with full
depth velocity and dual level temperature-salinity sensors).
Black dashed line marks boundary between US and Russian EEZ (Exclusive
Economic Zones). Blue solid arrows indicate the main mean flow
which is towards the north. Purple arrow (ACC) marks the warm,
fresh Alaskan Coastal Current, present seasonally. Cyan arrow
(SCC) marks the cold, fresh Siberian Coastal Current present only in
some years in some seasons.
|
|
|
