assessing the long-term contribution of landfast ice to the arctic freshwater budget

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1 Freshwater Initiative 1 st All-Hands meeting, Boulder, 18-19 February 2003

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Assessing the Long-term Contribution of Landfast Ice to the Arctic Freshwater Budget. Yanling Yu and Harry Stern Polar Science Center, Applied Physics Laboratory University of Washington. Some Facts about Landfast Ice. - PowerPoint PPT Presentation

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Page 1: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

1Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

Page 2: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

2Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

• Accounts for ~15% of the total annual mean ice cover in the Arctic Basin;

• Grows locally on the Arctic shelves and is primarily thermodynamically controlled;

• Produces ~2x103 km3 of ice volume annually;

• Shows a large interannual variability but is not well understood.

Page 3: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

3Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

Page 4: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

4Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

RADARSAT image on 1 June 1997 Because of its unique geolocation, landfast ice is directly involved with the coastal river runoff and the land-upper ocean interaction in terms of the freshwater cycle.

(http://www.ccrs.nrcan.gc.ca/ccrs/learn/tour/)

Page 5: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

5Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

As a shelf freshwater “reservoir”, landfast ice acts like a rechargeable battery, storing freshwater in winter and releasing it

later in summer.

Page 6: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

6Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

0200400

600800

100012001400

160018002000

Landfast Ice

Yenisey

Ob

Lena

Mackenzie

Total FourRiverDischarge

Annual Freshwater Storage (in cubic km)

Landfast ice stores about the same amount of freshwater as the total annual terrestrial discharge from the four largest Arctic rivers.

Page 7: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

77Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

Goals of this project are:Goals of this project are: examine the interannual fluctuation of examine the interannual fluctuation of

landfast extent for the whole Arctic Basin;landfast extent for the whole Arctic Basin; investigate the spatial & temporal investigate the spatial & temporal

variations in ice growth and melt patterns;variations in ice growth and melt patterns; analyze the long-term changes of ice analyze the long-term changes of ice

volume in terms of freshwater storage and volume in terms of freshwater storage and their responses to Arctic climate variations, their responses to Arctic climate variations, such as Ta, Wind, and major river runoff.such as Ta, Wind, and major river runoff.

Integrate research with educationAn undergraduate student will be involved with the project An undergraduate student will be involved with the project through the university’s Summer Undergraduate Student through the university’s Summer Undergraduate Student ProgramProgram

Page 8: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

8Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

What research

plans

?!

• Derive landfast ice extent/coverage from NIC weekly ice charts for the period 1976-1994 (2001)

• Compute daily landfast ice thickness, growth/melt, and ice volume for seven coastal regions associated with the major Arctic drainage basins

1-D thermodynamic sea ice model

(http://www.crysys.uwaterlo.ca/science/)

Page 9: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

9Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

Determine Long-Term changes of Determine Long-Term changes of landfast icelandfast ice

Compare these changes with seasonal and Compare these changes with seasonal and interannual variations interannual variations

of river runoff, air temperatures, wind, of river runoff, air temperatures, wind, and the AO indexand the AO index

Page 10: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

10Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

Possible Connections with Other ProjectsPossible Connections with Other Projects

Page 11: Assessing the Long-term Contribution of Landfast Ice  to the Arctic Freshwater Budget

11Freshwater Initiative 1st All-Hands meeting, Boulder, 18-19 February 2003

Updated river discharge data;Updated river discharge data;

Coastal/shelf water observations, such as Coastal/shelf water observations, such as TTss, , salinity, Oxygen isotope samples;salinity, Oxygen isotope samples;

Landfast ice thickness observations;Landfast ice thickness observations;

Model simulations of shelf processes.Model simulations of shelf processes.

Data Gaps?Data Gaps?