ATM OCN (Meteorology) 100
ATMOSPHERIC OPTICAL PHENOMENA
Summer 2001
Lecture #12 scheduled for:
10 JUL 2001 (T)
Recommended Readings from Moran and Morgan (1997):
pages 190-197.
Today's Lecture Objectives:
- To explain the physical causes for some common atmospheric optical phenomena.
- To distinguish between scattering, reflection, refraction, dispersion and diffraction processes.
- To know where and when to look for the various optical phenomena.
- To indicate the meteorological significance associated with some of these optical phenomena.
- To identify the reasons for blue sky, white clouds and red sunsets.
- To explain why the moon and sun are visible after they have actually passed below the horizon.
- To explain the formation of a mirage.
- To compare and contrast the formation of haloes, coronas and glories.
- To identify the features of primary and secondary rainbows.
Outline:
A. INTRODUCTION
- Definition and Scope
- Historical Background
B. NATURE OF VISIBLE LIGHT
- The Electromagnetic Spectrum
- Visible Light, Sunlight and The Electromagnetic Spectrum
- Visible Light, Color and Human Visual Perception
C. REVIEW OF OPTICAL PROCESSES
- Scattering
- Reflection
- Refraction
- Dispersion
- Diffraction
D. ATMOSPHERIC OPTICAL PHENOMENA
- Optical Phenomena associated with Small Particles in the Atmosphere
- Blue Skies
- White Clouds
- Red Sunsets
- Optical Phenomena associated with Vertical Air Density Gradients
- Optical Phenomena associated with Liquid Water Drops/Droplets in the Air
- Optical Phenomena associated with Ice Crystals in the Air
- Haloes
- Parhelia (Sun Dogs)
- Sun Pillars
Links to Other References:
- Some optical phenomena can be found on the Internet with the Light & Optics module from Weather World 2010 (Univ. of Illinois-Urbana-Champaign).
- For a tutorial on basic optics principles and atmospheric optical phenomena from Prof. Steve Ackerman of the Dept. of Atmospheric and Oceanic Sciences, UW-Madison.
For educational resource from UCAR Blue Sky Exhibit
Last revision 5 June 2001 (1425 UTC)
Produced by Edward J. Hopkins, Ph.D.
Department of Atmospheric and Oceanic Sciences
University of Wisconsin-Madison Madison, WI 53706
hopkins@meteor.wisc.edu
URL: aos100/lectures/s0112opt.html