Are the Wildfires Out West Creating More Colorful Sunsets?
by Daphne Thompson, on Aug 10, 2018 2:15:36 PM
Have you noticed that sunsets are more colorful lately? Have you caught yourself grabbing your phone or camera to capture a photo of spectacular red skies as the sun goes down? If so, the reason could be due to smoke in the atmosphere from the many wildfires out west.
Before we go into why the sky turns red, let's first answer the question all small children ask; why is the sky blue? While light may look white, when you use a prism it will break down into a rainbow of colors. Each of these colors travels on a different wavelength with blue having the shortest. As light goes through the atmosphere, the longer wavelength colors keep moving, but blue ends up encountering molecules in the sky and being absorbed. The color is then scattered in every direction so that when you look outside, the sky appears blue.
So then, why are sunsets red? The lower the sun gets in the sky, the further the distance that light has to travel through the atmosphere to get to you. As this happens, the various wavelengths of visible light get scattered until you are only left with the longer ones. Reds and oranges have the longest wavelengths, and as they reach your eye, the sky will turn those colors.
Smoke and dust can enhance the colors of a sunset even further. If you are close to the location of a fire, smoke will be low, and you will be left with everything looking hazy. But when these tiny molecules get higher in the atmosphere, they further enhance the scattering of shorter wavelengths. You will end up seeing even purer pinks, oranges, and reds. The smaller and more abundant the molecule, the redder the sky will appear. After a massive volcanic eruption, sunsets are historically known to be more vibrant than ever. That is because smoke from volcanoes can reach many miles up in the atmosphere and are the molecules are smaller in size than that of dust.
You also need the right type of clouds for some of the best sunrises and sunsets. Mid to high-level clouds, like cirrus and altostratus, help reflect the warm colors best as they are receiving sunlight that hasn't been as polluted as those in lower levels where pollution and haze are found.
The crew aboard the station took some incredible photographs of the northern California wildfires over three days from their orbital perspective 250 miles above Earth's surface. https://t.co/8bTtC0Jgit pic.twitter.com/P9MuaBNKl0— Intl. Space Station (@Space_Station) August 9, 2018
Due to the numerous large wildfires out west, smoke is being blown across much of the United States. While extremely destructive to those in California and Oregon, we might as well look for a silver lining. So, keep your cameras ready to go and watch for those colorful sunsets.