Earth:Crepuscular rays
Crepuscular rays are sunbeams that originate when the Sun is just below the horizon, during the twilight period.[1] Crepuscular rays are noticeable when the contrast between light and dark is most obvious. Crepuscular comes from the Latin word crepusculum, meaning "twilight".[2] Crepuscular rays usually appear orange because the path through the atmosphere at sunrise and sunset passes through up to 40 times as much air as rays from a high Sun at midday. Particles in the air scatter short-wavelength light (blue and green) through Rayleigh scattering much more strongly than longer-wavelength yellow and red light.
Loosely, the term crepuscular rays is sometimes extended to the general phenomenon of rays of sunlight that appear to converge at a point in the sky, irrespective of time of day.[3][4]
See also
References
- ↑ Naylor, John (2002). Out of the Blue: A 24-Hour Skywatcher's Guide. Cambridge University Press. pp. 77–79. ISBN 9780521809252. https://books.google.com/books?id=ZQOJGerV2IcC&pg=PA77.
- ↑ Edens, Harald. "Crepuscular rays". weatherscapes.com. http://www.weatherscapes.com/album.php?cat=optics&subcat=crepuscular_rays.
- ↑ "Crepuscular Rays". https://www.atoptics.co.uk/atoptics/ray1.htm.
- ↑ "Weather Facts: Crepuscular rays | weatheronline.co.uk". https://www.weatheronline.co.uk/reports/wxfacts/Crepuscular-rays.htm.
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