Correlation of Under-Ice Roughness with Satellite and Airborne Thermal Infrared Data.

• Main Author: LeSchack,Leonard A
• Other Authors: LESCHACK ASSOCIATES LTD SILVER SPRING MD
• Format: Text
• Language: English
• Published: 1980
• Subjects: Snow; Ice and Permafrost; Infrared Detection and Detectors; *DEPTH; *SURFACE TEMPERATURE; *INFRARED SCANNING; *PACK ICE; AERIAL RECONNAISSANCE; PROFILES; TABLES(DATA); ACOUSTIC ATTENUATION; CORRELATION TECHNIQUES; SKEWNESS; ROUGHNESS; STANDARD DEVIATION; DISTRIBUTION FUNCTIONS; RECONNAISSANCE SATELLITES; ARCTIC OCEAN; Kurtosis; WUNR307374; Arctic; Arctic Ocean; Beaufort Sea; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA085512; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA085512

This report, based on empirical data, concludes that a correlation has been found between easily obtainable sea ice surface temperature and under-ice roughness data which are obtainable only at great expense. Under-ice roughness is valuable in evaluating acoustic attenuation beneath the Arctic ice and is expressed in terms of either root-mean-square (RMS) ice depth or standard deviation about the mean ice depth, both of which are closely correlated. By showing a functional relationship between the skewness of the surface temperature distribution as derived from NOAA VHRR Satellite thermal infrared data and the under-ice roughness, the way appears clear to make a chart of Arctic under-ice roughness for Arctic acoustic programs and for nuclear submariners. In a second study, under ice data recorded in April 1976 by the SSN GURNARD was correlated with the skewness of temperature distributions derived from NOAA VHRR IR data recorded in March 1976 over nominally the same area of the Beaufort Sea. A third study was then conducted that shows, perhaps more graphically than the others, the correlation of under-ice data recorded by the British nuclear submarine HMS SOVEREIGN between 18-21 October 1976 with airborne IR data recorded during the same period over the submarine track by a Canadian Forces Argus aircraft. In all three examples, when the RMS ice depth range was between 4 and 8 m, corresponding to a standard deviation of ice depth ranging between 2 and 6 m, there is a strong, negative linear correlation between the skewness of the temperature distributions, whether measured from satellites or aircraft, and the under-ice roughness measured by submarine upward-looking sonar.