What makes mountains blue

Answer: Easily. All distant mountains appear blue for the same reason. The image above was taken in Arizona from my home north of Phoenix. The most distant mountains visible are part of South Mountain, about 70 km 44 miles to the south. They appear distinctly bluish.

All the mountains in this photo have the same vegetation, but the farther away they are, the bluer they appear. Their natural vegetation is more green, but they also show the effect. The cause is closely related to something called atmospheric extinction , discussed in my Feb 4, post.

The effect is due to Rayleigh scattering of light in our atmosphere. The classes of VOCs called terpenes are naturally occurring hydrocarbons emitted by conifers.

In the wild and in large numbers, all of those tiny molecules react with natural ozone molecules already in the air to form new particles and scatter blue light from the sun. You can learn more about the natural phenomena of the Blue Ridge Mountains at nps. Have you ever visited the Blue Ridge Mountains? By Southern Living. These are the colors visible to the human eye. Each color has a different wavelength, with red having the longest, and violet, on the other end of the spectrum, having the shortest.

A quick detour into biology tells us that the color receptors, or cones, in the retinas of our eyes respond best to the wavelengths of three colors of light-red, green, and blue. This reception is what gives us our color vision. We can thank Lord Rayleigh, who in the s, explained why.

He found that solar light passing through the atmosphere is broadly scattered before our eyes perceive it. Light passing through a medium containing small particles scatters the shorter blue wavelength more strongly than the red. This selective scattering is now known as Rayleigh scattering. Later scientists including Alfred Einstein, who settled the matter in concluded that the small molecules of oxygen and nitrogen in the air are more effective at scattering shorter wavelengths of light-the blue and violet end of the spectrum.

Since our eyes are not as sensitive to violet, the sky appears blue when you look up through the prism of air that constitutes our atmosphere. But you asked why our mountains-which are made up of many colors-appear blue. The blue-sky principle still holds: when you view a dark, solid object, such as a mountain, from a distance, the scattered light makes it appear blue.

Yet the distinct blue haze of the Appalachians can also be attributed to the thick vegetation that blankets the slopes.