Polarization of "water-skies" above arctic open waters: how polynyas in the ice-cover can be visually detected from a distance

Summary, in English

The foggy sky above a white ice-cover and a dark water surface (permanent polynya or temporary lead) is white and dark gray, phenomena called the "ice-sky" and the "water-sky," respectively. Captains of icebreaker ships used to search for not-directly-visible open waters remotely on the basis of the water sky. Animals depending on open waters in the Arctic region may also detect not-directly-visible waters from a distance by means of the water sky. Since the polarization of ice-skies and water-skies has not, to our knowledge, been studied before, we measured the polarization patterns of water-skies above polynyas in the arctic ice-cover during the Beringia 2005 Swedish polar research expedition to the North Pole region. We show that there are statistically significant differences in the angle of polarization between the water-sky and the ice-sky. This polarization phenomenon could help biological and man-made sensors to detect open waters not directly visible from a distance. However, the threshold of polarization-based detection would be rather low, because the degree of linear polarization of light radiated by water-skies and ice-skies is not higher than 10%. (c) 2006 Optical Society of America.

• Author: R Hegedus; Susanne Åkesson; G Horvath
• Department/s: Evolutionary ecology; Animal Navigation Lab
• Publishing year: 2007
• Language: English
• Pages: 132-138
• Publication/Series: Journal of the Optical Society of America A
• Volume: 24
• Issue: 1
• Links: http://www.opticsinfobase.org/abstract.cfm?URI=josaa-24-1-132
• Document type: Journal article
• Publisher: Optical Society of America
• Topic: Biological Sciences
• Status: Published
• Research group: Animal Navigation Lab
• ISBN/ISSN/Other: ISSN: 1084-7529