Sea ice loss enhances wave action at the Arctic coast
Abstract
Erosion rates of permafrost coasts along the Beaufort Sea accelerated over the past 50 years synchronously with Arctic-wide declines in sea ice extent, suggesting a causal relationship between the two. A fetch-limited wave model driven by sea ice position and local wind data from northern Alaska indicates that the exposure of permafrost bluffs to seawater increased by a factor of 2.5 during 1979-2009. The duration of the open water season expanded from ∼45 days to ∼95 days. Open water expanded more rapidly toward the fall (∼0.92 day yr-1), when sea surface temperatures are cooler, than into the mid-summer (∼0.71 days yr-1).Time-lapse imagery demonstrates the relatively efficient erosive action of a single storm in August. Sea surface temperatures have already decreased significantly by fall, reducing the potential impact of thermal erosion due to fall season storm waves.
- Publication:
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Geophysical Research Letters
- Pub Date:
- September 2011
- DOI:
- Bibcode:
- 2011GeoRL..3817503O
- Keywords:
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- Cryosphere: Sea ice (4540);
- Global Change: Cryospheric change (0776);
- Marine Geology and Geophysics: Continental shelf and slope processes (4219);
- Oceanography: General: Coastal processes