An Evaluation of Side Looking Radar Imagery of Sea Ice Features and Conditions in the Lincoln Sea, Nares Strait, and Baffin Bay.

• Main Author: Ketchum,R D , Jr
• Other Authors: NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY NSTL STATION MS
• Format: Text
• Language: English
• Published: 1977
• Subjects: Snow; Ice and Permafrost; Active & Passive Radar Detection & Equipment; *SEA ICE; *SIDE LOOKING RADAR; RADAR; ICE FORMATION; IMAGES; CLIMATE; SUBMARINES; UNDERWATER COMMUNICATIONS; ARCTIC OCEAN; WU325; PE62759N; Arctic; Arctic Ocean; Baffin Bay; Nares; Baffin; Ice; Lincoln Sea; Nares strait; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA079755; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA079755

Evaluation of synthetic aperture radar sea ice imagery has shown that discrimination of first season ice types can be difficult due to ambiguous radar returns. It has been hypothesized that varying balances of ice thickness, snow depth, air temperature, and time will produce conditions at the snow-ice interface which are conducive to the development of radar reflective suraces with variable backscatter characteristics. The presence of this phenomenon was common in Baffin Bay where climatic conditions fluctuate widely. This phenomenon should be anticipated in other areas of the marginal ice zone. Multi-year ice forms were easy features to identify. Generally uniform returns from multi-year ice are believed to be due to volume scattering. Many of the larger frozen melt ponds on multi-year ice were identifiable. It is hypothesized that the radar energy penetrates the fresh water ice which comprises these ponds and is attenuated in the underlying multi-year ice. High returns seen within some of these ponds are believed to come from areas where thaw holes formed during the previous melt season. The question of the penetrability of large vertical sections of multi-year ice, particulary by longer wavelengths, is raised. This question deserves serious consideration because of the possible implication on air to submarine communication. (Author)