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Optical properties of melting first‐year A rctic sea ice
Author(s) -
Light Bonnie,
Perovich Donald K.,
Webster Melinda A.,
Polashenski Christopher,
Dadic Ruzica
Publication year - 2015
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2015jc011163
Subject(s) - sea ice , sea ice thickness , arctic ice pack , albedo (alchemy) , melt pond , ice albedo feedback , snow , atmospheric sciences , sea ice concentration , arctic , environmental science , geology , antarctic sea ice , cryosphere , climatology , oceanography , geomorphology , art , performance art , art history
The albedo and transmittance of melting, first‐year Arctic sea ice were measured during two cruises of the Impacts of Climate on the Eco‐Systems and Chemistry of the Arctic Pacific Environment (ICESCAPE) project during the summers of 2010 and 2011. Spectral measurements were made for both bare and ponded ice types at a total of 19 ice stations in the Chukchi and Beaufort Seas. These data, along with irradiance profiles taken within boreholes, laboratory measurements of the optical properties of core samples, ice physical property observations, and radiative transfer model simulations are employed to describe representative optical properties for melting first‐year Arctic sea ice. Ponded ice was found to transmit roughly 4.4 times more total energy into the ocean, relative to nearby bare ice. The ubiquitous surface‐scattering layer and drained layer present on bare, melting sea ice are responsible for its relatively high albedo and relatively low transmittance. Light transmittance through ponded ice depends on the physical thickness of the ice and the magnitude of the scattering coefficient in the ice interior. Bare ice reflects nearly three‐quarters of the incident sunlight, enhancing its resiliency to absorption by solar insolation. In contrast, ponded ice absorbs or transmits to the ocean more than three‐quarters of the incident sunlight. Characterization of the heat balance of a summertime ice cover is largely dictated by its pond coverage, and light transmittance through ponded ice shows strong contrast between first‐year and multiyear Arctic ice covers.