1. References: http://vista.cira.colostate.edu/improve/ Acidic Deposition:State of Science and Technology (report 24) 1990 Visibility: Existing and Historical Conditions – Causes and Effects Introduction to Visibility (WC Malm) issn 0737-5352-40 (CIRA-CSU)

2. What is Visibility? n Historically visibility was thought of in terms of the furthest distance one could see a large black object. n From a scenic vista perspective, there’s more interest in color, line, texture, and form of a scenic landscape feature.

3. How far can you see?

10. Great Smoky Mountains National Park

11. Yosemite National Park

12. Glacier National Park

13. Canyonlands National Park

14. Big Bend National Park

15. Layered Hazes

17. The Seeing of a Landscape Feature

18. Relationship Between Aerosols and Optical Properties

19. The extinction coefficient is made up of particle and gas scattering and absorption: where s, a, g, and p refer to scattering, absorption, gases, and particles, respectively. Extinction =

20. Scattering Efficiency (Q)

21. Single Particle Efficiency

22. Particle Size Distribution

23. Scattering Efficiency as Function of Size

24. Carbon Extinction Efficiency

25. Phase Function for Soil and Sulfate

26. Phase Function for Carbon

27. Forward and Backward Scattering

28. On the Nature of Light n Wave-like characteristics of light n Electromagnetic radiation n Photons and color n Why objects are colored n Atmospheric optical effects

29. IntroVis.exe