Coastal ice at Barrow
NB: This page is still under construction, in the meantime, feel free to read a bit about fast ice below ...
The Arctic sea-ice cover is of disproportionate importance in the climate system because it restricts the energy exchange between ocean and atmosphere and greatly reduces the amount of solar shortwave energy supplied to the ocean-ice-atmosphere system (Maykut, 1986, Barry et al., 1993). It is generally assumed that apart from merely responding to changes in the longwave/shortwave forcing or the poleward transport of heat and moisture, the sea-ice cover can amplify such changes through positive feedback processes that originate from the albedo contrast between open water and ice surfaces (Curry et al., 1995). The analysis of longer-term data sets and modelling indicate substantial reductions in both the extent and thickness of the Arctic sea-ice cover during the past 20 to 40 years (Maslanik et al., 1996, Cavalieri et al., 1997, Rothrock et al., 1999, Vinnikov et al., 1999). However, interpretation of such changes in the context of global climate change is severely hampered by the substantial natural variability inherent in the Arctic system (Proshutinsky and Johnson, 1997, Thompson and Wallace, 1998, Dickson, 1999). More importantly, the thermodynamic response of the ice pack to changes in the poleward heat transport or longwave/shortwave forcing can be masked or partially compensated by dynamic processes such as rafting or ridging of new ice produced in leads (Wadhams, 1994, Flato and Hibler, 1995).
The Arctic land-fast sea-ice cover, on the other hand, is only marginally affected by such deformational processes and hence provides a much stronger indication of changes in the relevant atmospheric (and oceanic) forcing parameters and their unmitigated impact on the sea-ice cover. Time-series of fast-ice extent, thickness and date of formation or decay can thus be of considerable value as integral measures of climate variability and change. This has long been recognized and has motivated longer-term programs devoted to the acquisition of fast-ice data at selected locations in the North American and Siberian Arctic (Zubov, 1945, Bilello, 1980, Brown and Cote, 1989, Flato and Brown, 1996).
Due to its location at a critical juncture between land and ocean, the importance of the Arctic fast-ice cover extends to a number of other coastal processes that figure prominently in the context of climate variability and change. Thus, the fast-ice cover is also of great importance for the ecology of the coastal zone and it furthermore figures prominently in the lifestyle of the indigenous population both in the Alaskan Arctic (ARCUS, 1997).
If you are interested in learning more about traditional indigenous knowledge and perception of sea ice, you might want to look up a set of web pages outlining "Inuit Knowledge of Sea Ice in a Geophysical Setting", prepared by Dan Elsberg at the University of Alaska Fairbanks as part of a student course project. A short, annotated Glossary of sea-ice terms is also available.
To be completed ...
Last update: April 30, 2000