INFERRING ICE BASAL ROUGHNESS FROM HIGH RESOLUTION SYNTHETIC APERTURE RADAR SATELLITE IMAGERY

During the past decade, direct measurements of ocean turbulent friction velocity and current velocity profiles have been conducted in polar regions using Autonomous Ocean Flux Buoys (AOFBs). Recent use of Synthetic Aperture Radar (SAR) imagery augmented by digital image processing techniques has proven to be an effective means of monitoring ice conditions. This study examines the relationship between ice-ocean drag coefficients and SAR-derived open water area, feature perimeter and ice ridge length. Drag coefficients are calculated from AOFB current speed and friction velocity measurements collected between 5 October and 29 October 2018 in the Beaufort Sea. Threshold and image processing techniques were applied to a total of 82 SAR images at 6 logarithmically spaced radial upstream distances from the AOFB to classify the three ice feature types. The results indicate that sparse statistics associated with the size and image processing limitations within the near field of the AOFB, coupled with a lack of high resolution satellite imagery, stifled the SAR’s ability to accurately characterize the relationship between ice-ocean drag coefficients and ice feature density distributions within upstream radial sectors within the buoy-centered 20 x 20 km SAR images.http://archive.org/details/inferringicebasa1094564174Lieutenant, United States NavyApproved for public release; distribution is unlimited