Crepuscular rays

Crepuscular rays are sunbeams that originate when the sun is just below the horizon, during twilight hours.[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 midday sun. Particles in the air scatter short wavelength light (blue and green) through Rayleigh scattering much more strongly than longer wavelength yellow and red light.

Crepuscular rays as seen from Taipei, Taiwan; 2018

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
  1. Naylor, John (2002). Out of the Blue: A 24-Hour Skywatcher's Guide. Cambridge University Press. pp. 77–79. ISBN 9780521809252.
  2. Edens, Harald. "Crepuscular rays". Weather Photography lightning, clouds, atmospheric optics & astronomy. Retrieved November 1, 2011.
  3. "Crepuscular Rays".
  4. "Weather Facts: Crepuscular rays | weatheronline.co.uk".

Media related to Crepuscular rays at Wikimedia Commons


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