 The Western Arctic from the CBL 2002 cruise
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HIGH LATITUDE DYNAMICSObservational-based Studies of Physical Processes in Ice-covered Waters, especially the Arctic
University of Washington 1013 NE 40th Street, Seattle, WA 98105, U.S.A. |
WHAT'S NEW??? |
The Changing Arctic Ocean
- website for UW interdisciplinary graduate course by Jody Deming and Rebecca Woodgate, Spring Quarter 2007 The Future of Arctic Sea-Ice - website from Polar Science Weekend 2007 at the Pacific Science Center, Seattle |
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We aim to study and
understand:
- physical processes in the high latitude oceans, including large-scale circulation, shelf-basin interactions, and water mass formation ; - linkages between polar oceans and the lower latitudes ; - the role of polar processes in climate. We
do this primarily with observations, drawing on theory and modelling
results to explain processes we observe.
We analyze the data
from the moorings and from the CTD using
geophysical fluid dynamics, and compare results with simulations from
numerical models.
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At any time, we work on many different projects. Current major projects are: Bering Strait - Pacific Gateway - The ~ 85 km wide, ~ 50 m deep Bering Strait, at the northern end of the Pacific Ocean, is the only oceanic link between the Pacific and the Arctic. The flow through the strait is (in the mean) northwards, and is an important source of freshwater, heat and nutrients for the Arctic Ocean. Recent measurements suggest an increase in heat flux through the strait. We aim to measure and quantify the Bering Strait fluxes of heat, freshwater and nutrients, and provide a measurement platform for other studies in the region. Chukchi Borderland - Arctic Crossroads - Some 600 miles north of the Bering Strait, about 800 miles south of the north pole, is a region of complex sea floor topography known as the Chukchi Borderland. In this region, the nutrient-rich Pacific waters from the Bering Strait meet and interact with the warmer saltier Atlantic waters that entered the Arctic via Fram Strait. Recent results show that a warming of the Fram Strait waters reached this region in the early 2000s. In 2002, we performed an intensive hydrographic survey of the Chukchi Borderland region, to elucidate water mass pathways and important physical processes. North Pole Environmental Observatory- As part of this long term observatory, we are maintaining a subsurface mooring at the North Pole. This mooring is anchored to the sea floor and stretches to within 50 m of the surface. This makes it over 4km (2.5 miles) long. The mooring measures water velocity and water properties in the major layers of the Arctic Ocean (the upper halocline layer, the lower Atlantic layer, and the deeper layers), and also records ice thickness and ice motion. SBI Chukchi - The Chukchi Sea, ~ 500 km wide (east-west) and ~ 800 km long (north-south) is a shallow (~ 50 m deep) shelf sea just north of the Bering Strait and south of the Arctic Ocean proper. It is fed from the south by the Pacific water throughflow through the Bering Strait. As part of the SBI (Shelf-Basin-Interaction) project, we have been studying the flow and transformation of waters in the Chukchi Sea, and measuring pathways, volume and water properties of the Pacific waters that exit the Chukchi Sea into the Arctic Ocean. BEST - Bering Sea Ecosystem Study (PIs: Jinlun Zhang and Rebecca Woodgate) - The Bering Sea - lying at the northern end of the Pacific Ocean and north of the Aleutian Chain - is the source of over 50% of the total US fish catch and the home to immense populations of birds and marine mammals. The Bering Sea ecosystem is strongly tied to the seasonal sea-ice, which influences the oceanic environment of the region and also provides a habitat for many species. Recent years have shown significant climate regime shifts in the Bering Sea. As part of the new NSF Bering Ecosystem Study (BEST), we plan to use a state-of-the-art numerical ocean-ice model to investigate prior (and predict future) changes in the Bering Sea ice cover and study the impacts of these changes on Bering Sea marine and eco-systems. |
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Prior research includes topics such as: Arctic Circulation at the Lomonosov Ridge - The major circum Arctic ocean circulation pathway is the Arctic Ocean Boundary Current, an equivalent barotropic current that moves cyclonically (anticlockwise) along the continental shelves of the major ocean basins. Using mooring data from 1995 to 1996 from the Eurasian end of the Lomonosov Ridge, we study how the Lomonosov Ridge splits the Arctic Ocean Boundary Current, with about half the boundary current moving north along the ridge and the other half continuing along the continental slope. St.Lawrence Polynya - In the northern Bering Sea, when atmospheric conditions are right in winter, a major ocean polynya forms just south of St. Lawrence Island. A dedicated field effort, including year-round moored instrumentation, tested theoretical ideas about shelf convection and the spreading of ventilated water away from the convecting region. Fram Strait - On the European side of the Arctic, the Fram Strait is the major deep entrance to the Arctic ocean and the primary southward conduit for Arctic freshwater (in the form of water or ice) into the Greenland Sea and North Atlantic. In a joint US-American project, we have measured year-round ice thickness and studied the primary mechanisms controlling the ice flux through the Fram Strait. Beaufort Sea - Circulation in the Beaufort Sea, with an emphasis on the Boundary Current Lake Superior - Circulation, convection and frontal processes in Lake Superior. Arctic change from Russian Data - Interannual and decadal variability of temperature and other water properties from an enhanced version of the 1948-1993 data released under the Gore-Chernomyrdin environmental bilateral agreement. |
