WW2010
University of Illinois

WW2010
 
  welcome
 
> online guides
 
  archives
 
  educational cd-rom
 
  current weather
 
  about ww2010
 
  index

Online Guides
 
  introduction
 
> meteorology
 
  remote sensing
 
  reading maps
 
  projects, activities

Meteorology
 
  introduction
 
  air masses, fronts
 
  clouds, precipitation
 
  el nino
 
  forces, winds
 
  hurricanes
 
  hydrologic cycle
 
> light, optics
 
  midlatitude cyclones
 
  severe storms
 
  weather forecasting

Light, Optics
 
  introduction
 
  mechanisms
 
  air, dust, haze
 
  ice crystals
 
> water droplets

water droplets
 
  coronas
 
  linings, iridescence
 
> rainbows

Rainbows
 
  how they develop
 
  primary rainbow
 
> secondary rainbow

User Interface
 
  graphics
> text

NOTE: We've guessed that you're not using a client that supports colored tables and have tried to compensate. Low graphics mode looks much better on clients that do... we recommend switching to Netscape 3.0 or Microsoft Internet Explorer.
.
Secondary Rainbows
fainter than a primary rainbow

A secondary rainbow appears outside of a primary rainbow and develops when light entering a raindrop undergoes two internal reflections instead of just one (as is the case with a primary rainbow). The intensity of light is reduced even further by the second reflection, so secondary rainbows are not as bright as primary rainbows. Alternatively: fewer light rays go through the four-step sequence than the three-step sequence.

[Image: a secondary rainbow (43K)]
Photograph by: Olthoff

The color scheme of the secondary rainbow is opposite of the primary rainbow. Violet light from the higher drop enters the observer's eye, while red light from the same drop is incident elsewhere.

Simultaneously, red light from the lower drop enters the observer's eye and violet light is not seen. This is why the colors of a secondary rainbow change from violet on the top to red on the bottom.



primary rainbow
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

Midlatitude Cyclones