Why Does Arizona Have Such Beautiful Sunsets

Having just seen a few incredible sunsets here in Arizona, it got me to wondering why does Arizona have such beautiful sunsets.

I did some research and found out  there is some science behind the way light refracts in the atmosphere and that certain conditions exist in Arizona that create these incredibly colorful sunsets.

According to Stephen Corfidi from the NOAA/NWS Storm Prediction Center, “Ordinary sunlight is composed of a spectrum of colors that grade from violets and blues at one end to oranges and reds on the other. The wavelengths in this spectrum range from .47 um for violet to .64 um for red. Air molecules are much smaller than this — about a thousand times smaller. Thus, air is a good Rayleigh scatterer. But because air molecules are slightly closer in size to the wavelength of violet light than to that of red light, pure air scatters violet light three to four times more effectively than it does the longer wavelengths. In fact, were it not for the fact that human eyes are more sensitive to blue light than to violet, the clear daytime sky would appear violet instead of blue!

At sunrise or sunset, sunlight takes a much longer path through the atmosphere than during the middle part of the day. Because this lengthened path results in an increased amount of violet and blue light being scattered out of the beam by the nearly infinite number of scattering “events” that occur along the way (a process collectively known as multiple scattering), the light that reaches an observer early or late in the day is noticeably reddened. Thus, it could be said that sunsets are red because the daytime sky is blue. This notion is perhaps best illustrated by example: A beam of sunlight that at a given moment helps produce a red sunset over the Appalachians is at the same time contributing to a deep blue, late afternoon sky over the Rockies.”

Think about it.  If dust and pollution were responsible for beautiful sunsets, the most talked about and photographed sunsets would be in New York City, Los Angeles and other densely populated cities with lots of pollution.  Pollution and dust actually detract from beautiful sunsets.  They scatter the light and subdue the colors.  The key elements for a beautiful sunsets are clean air along with high thin clouds. The sun’s rays hit the high clouds before passing through the atmosphere adding texture and gradations of lighting.

Do you have a favorite sunset photo?  If, so you can share it with the Arizona Tourism audience by uploading it.  Just click here to upload your photos.  We’ll email you once the photo has been published and include your name in the photo credit along with a link back to you site if you have one.