Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Zenith polarization and color ratio during twilight

Not Accessible

Your library or personal account may give you access

Abstract

The excellent data of zenith polarization and color ratio (CR) during twilight obtained by Coulson at the Mauna Loa Observatory, Hawaii are subjected to a reinterpretation, especially with regard to the frequent deviations from the clear average. It is shown that a moderate lift of the earth’s shadow by distant clouds (or by low level haze) will reduce the red/green CR, while greater lift shifts the CR peak to a smaller solar depression. The effect on zenith polarization at wavelengths 0.6 μm is seen to correspond to a slight reduction of overall polarization for a moderate lift, and for a large lift to a shift of the polarization minimum (depolarization by stratospheric aerosol) from 4° solar depression angle to 2°. A generally high level of polarization, but with a barely noticeable 4° minimum, had also been observed earlier in Germany by Steinhorst when the stratospheric aerosol load was very small. The difference is explained by a higher and stronger aerosol layer in the tropics combined with a higher and cleaner troposphere.

© 1981 Optical Society of America

Full Article  |  PDF Article
More Like This

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (4)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved