The Optical Properties of Sea Ice.

• Main Author: Perovich, Donald K.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
• Format: Text
• Language: English
• Published: 1996
• Subjects: Snow; Ice and Permafrost; Optics; *OPTICAL PROPERTIES; *SEA ICE; FREQUENCY; EXTINCTION; VOLUME; SCATTERING; AIR; LIQUIDS; PHYSICAL PROPERTIES; THERMODYNAMICS; WATER; ARRAYS; RADIATIVE TRANSFER; TRANSMITTANCE; SURFACES; DRAINAGE; SNOW COVER; ICE; SURFACE PROPERTIES; COEFFICIENTS; BUBBLES; ABSORPTION; REFLECTANCE; BRINES; ALBEDO; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA310586; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA310586

Sea ice is a translucent material with an intricate structure and complex optical properties. Understanding the reflection, absorption, and transmission of shortwave radiation by sea ice is important to a diverse array of scientific problems, including those in ice thermodynamics and polar climatology. Radiative transfer in sea ice is a combination of absorption and scattering. Differences in the magnitude of sea ice optical properties are due primarily to differences in scattering. Spectral variations are mainly a result of absorption. Changes in such optical properties as the albedo, reflectance, transmittance, and extinction coefficient are directly related to changes in the state and structure of the ice. Physical changes that enhance scattering, such as the formation of air bubbles due to brine drainage, result in larger albedos and extinction coefficients. The albedo is quite sensitive to the surface state. If the ice has a snow cover, albedos are large. In contrast, the presence of liquid water on a bare ice surface causes a decrease in albedo, which is more pronounced at longer wavelengths. Sea-ice optical properties depend on the volume of brine and air and on how the brine and air are distributed.