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Implications of fractured Arctic perennial ice cover on thermodynamic and dynamic sea ice processes
Author(s) -
Asplin Matthew G.,
Scharien Randall,
Else Brent,
Howell Stephen,
Barber David G.,
Papakyriakou Tim,
Prinsenberg Simon
Publication year - 2014
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2013jc009557
Subject(s) - sea ice , arctic ice pack , geology , drift ice , arctic , antarctic sea ice , arctic sea ice decline , fast ice , sea ice thickness , melt pond , arctic geoengineering , climatology , oceanography , environmental science
Decline of the Arctic summer minimum sea ice extent is characterized by large expanses of open water in the Siberian, Laptev, Chukchi, and Beaufort Seas, and introduces large fetch distances in the Arctic Ocean. Long waves can propagate deep into the pack ice, thereby causing flexural swell and failure of the sea ice. This process shifts the floe size diameter distribution smaller, increases floe surface area, and thereby affects sea ice dynamic and thermodynamic processes. The results of Radarsat‐2 imagery analysis show that a flexural fracture event which occurred in the Beaufort Sea region on 6 September 2009 affected ∼40,000 km 2 . Open water fractional area in the area affected initially decreased from 3.7% to 2.7%, but later increased to ∼20% following wind‐forced divergence of the ice pack. Energy available for lateral melting was assessed by estimating the change in energy entrainment from longwave and shortwave radiation in the mixed‐layer of the ocean following flexural fracture. 11.54 MJ m −2 of additional energy for lateral melting of ice floes was identified in affected areas. The impact of this process in future Arctic sea ice melt seasons was assessed using estimations of earlier occurrences of fracture during the melt season, and is discussed in context with ocean heat fluxes, atmospheric mixing of the ocean mixed layer, and declining sea ice cover. We conclude that this process is an important positive feedback to Arctic sea ice loss, and timing of initiation is critical in how it affects sea ice thermodynamic and dynamic processes.