The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Polarization patterns of thick clouds: overcast skies have distribution of the angle of polarization similar to that of clear skies

Author

Summary, in English

The distribution of polarization in the overcast sky has been practically unknown. Earlier the polarization of light from heavily overcast skies (when the Sun's disc was invisible) has been measured only sporadically in some celestial points by point-source polarimetry. What kind of patterns of the degree p and angle a of linear polarization of light could develop after transmission through a thick layer of ice or water clouds? To answer this question, we measured the p and a patterns of numerous totally overcast skies on the Arctic Ocean and in Hungary by full-sky imaging polarimetry. We present here our finding that depending on the optical thickness of the cloud layer, the pattern of a of light transmitted through the ice or water clouds of totally overcast skies is qualitatively the same as the a pattern of the clear sky. Under overcast conditions the value of a is determined predominantly by scattering on cloud particles themselves. Nevertheless, the degrees of linear polarization of light from overcast skies were rather low (p <= 16 %). Our results obtained under overcast conditions complete the earlier findings that the a pattern of the clear sky also appears in partly cloudy, foggy, and smoky skies. Our results show that the celestial distribution of the direction of polarization is a very robust pattern being qualitatively always the same under all possible sky conditions. This is of great importance for the orientation of polarization-sensitive animals based on sky polarization under conditions when the Sun is not visible. (c) 2007 Optical Society of America.

Publishing year

2007

Language

English

Pages

2347-2356

Publication/Series

Journal of the Optical Society of America A

Volume

24

Issue

8

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