Snow-sky and water-sky luminance at an Arctic station

• Published in: Polar Research
• Main Author: Hisdal, Vidar
• Format: Article in Journal/Newspaper
• Language: English
• Published: Norwegian Polar Institute 1982
• Subjects: Arctic; Svalbard; Polar Research
• Online Access: https://polarresearch.net/index.php/polar/article/view/2576; https://doi.org/10.3402/polar.v1982i2.7002

Luminance measurements of water-sky and snow-sky were carried out at Ny-Alesund, Svalbard. The luminance of a well-developed water-sky is found to be about 40% of that of the adjacent snow-sky. Once the‘luminance level’of a comparatively pure snow-sky is reached, there is only a very slight further luminance increase towards zenith. This is in good agreement with FRITZ’theory as well as with the light conditions experienced during‘white-out’situations. By measuring the angular elevation of the border between water-sky and snow-sky and the height of the cloud base, good estimates are obtained of the distance to the corresponding border on the ground between snow surface and open water.