Quantitative Use of Satellite Vidicon Data for Delimiting Sea Ice Conditions

Résumé

Although television pictures from Earth satellites have been used for over ten years to detect major sea ice features, direct photo-interpretation methods have been supplemented with a fully-automated technique employing Composite Minimum Brightness (CMB) charts. Lack of on-board calibration has prevented quantitative use of the CMB method. In a newly-developed procedure the satellite brightness measurements taken over selected areas are used for external calibration. The calibrated data were used to study sea ice conditions in the North American Arctic. Characteristic brightness levels were found corresponding to the following: 1) compact or very close pack, snow covered; 2) compact or very close pack, without snow but with little or no puddling; 3) very close to close pack with much puddling; 4) open pack, generally with much puddling and rotten ice; 5) very open pack or ice-free conditions.