The extraction of marginal-ice-zone thickness using gravity wave imagery

Abstract

Synthetic aperture radar (SAR) imagery of gravity waves in the Fram Strait marginal ice zone (MIZ) were acquired during 1987 using aircraft flying over the Greenland Sea. The dominant gravity wavelengths exhibit a systematic lengthening with penetration distance into the MIZ for three different regions examined. The extracted dominant wavelengths were analyzed using a linear least square fit with penetration distance and a flexure-gravity wave model to estimate mean ice thickness. The extracted mean thickness varies from about 1/spl plusmn/0.4 m near the ice edge to approximately 2/spl plusmn/0.4 m near the deepest detectable penetration of the waves, about 20 km. These thicknesses are in agreement with 31 in-situ measurements taken in the Fram Strait MIZ within two weeks of the SAR measurements.<>