Investigations of Sea Ice Anisotropy, Electromagnetic Properties, Strength, and Under-Ice Current Orientation,
Abstract
Results of impulse radar studies of sea ice give support to the concept of a sea ice model in which the ice bottom is composed of an array of lossy parallel plate waveguides. The fundamental relation between the average bulk brine volume of sea ice and its electrical and strength properties is discussed as is the remote detection of under-ice current alignment. It was found that (1) the average effective bulk dielectric constant is dependent upon the average bulk brine volume of the sea ice; (2) sea ice anisotropy, arising from a bottom structure of crystal platelets with a preferred c-axis horizontal alignment, can be detected by radio echo sounding measurements made not only on the ice surface but also from an airborne platform; (3) the effective coefficient of reflection from the sea ice bottom decreases with increasing average effective bulk dielectric constant of the ice, decreases with increasing bulk brine volume, and is typically one to two orders of magnitude lower than the coefficient of reflection from the ice surface; and (4) the losses in sea ice increase with increasing average bulk brine volume. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1980
- Accession Number
- ADA092089
Entities
People
- Austin Kovacs
- Rexford M. Morey
Organizations
- Cold Regions Research and Engineering Laboratory