Albedo Measurements of an Arctic Ice Cover From High Towers

Abstract

Radiometers, suspended at a height of 15 m between two towers anchored to the bottom of the ice cover, have been used to measure the average or integrated albedo of the surface. The work was carried out in May 1967 at Tanquary Fiord, Ellesmere Island (lat. 81° 25′ N., long. 76° 50′ W.) during the period when the surface of the ice cover was undergoing rapid change. The albedo was observed to have a value of almost 1·0, for a fresh snow cover, and about 0·8 for a weathered snow cover. It decreased to 0·6 as the wind partially cleared the surface of snow and gradually to 0·5 with further deterioration of the snow. The onset of melting, produced when the daily mean temperature exceeded 0°C, rapidly lowered the albedo to a value of about 0·3.