PI:  Yanling Yu    
Co-PI:  Harry Stern   

Polar Science Center, Applied Physics Laboratory, University of Washington
1013 NE 40th Street, Seattle, WA 98105, U.S.A.

Overview

Landfast ice plays a unique role in the land-upper ocean freshwater cycle.  Formed in the shallow water along the Arctic coasts, landfast ice can lock up a significant amount of freshwater from river discharge and ice melt, but most of this freshwater will be returned back to the shelves during summer melting.  The freshwater stored in landfast ice is comparable to the total annual runoff of the four largest Arctic rivers.  As a freshwater "reservoir", landfast ice acts like a rechargeable battery, storing freshwater in winter and releasing it later in summer.  It is thus impossible to examine the land-upper ocean freshwater cycle without considering the freeze and thaw of landfast ice and its role and contribution.

The growth and melt of fast ice displays a large interannual variability.  Of climatic significance are the year-to-year changes in the storage and the timing of the released fresh water.  Recent observations indicate some substantial changes in the Arctic climate.  These changes may affect the freshwater exchange between the land and the upper ocean, partly through altering the growth and melting patterns of landfast ice.

Under the Arctic Freshwater Initiative funded by NSF, this project will examine the long-term changes in landfast ice and its contribution to the arctic freshwater budget. By modeling fast ice thickness and integrating these results with a 26-year record of landfast ice extent observation, this study will examine the basin-wide changes in landfast ice cover, including ice coverage, growth/melt, brine flux, and freshwater storage.  To relate the results to the Arctic climate variability, the study will also compare the changes in fast ice with different Arctic climate variables.

Project Goals

  Examine the interannual fluctuation of landfast ice extent for the whole Arctic Basin;

  Investigate the spatial and temporal changes in fast ice growth and melt as well as brine flux due to ice formation;

  Analyze the long-term changes in fast ice volume in terms of freshwater storage by landfast ice in response to the Arctic climate variations, such as changes in snowfall, surface air temperature, wind, and major river discharge.

  Integrate our research activities with university summer undergraduate program and get involved with student's learning process.

Sponsor

This project is funded by the National Science Fundation under grant OPP-0229473.