PORTLAND, Maine — The first 8 p.m. sunset of the year is Wednesday evening, and that got me thinking more about sunsets.
As summer nights approach and the sun sets later, we're going to begin enjoying each sunset filled with all of the warm colors, but why don't we see all the colors of the rainbow?
It all has to do with how the atmosphere scatters light.
Visible light is made up of the entire rainbow, and each color has its own wavelength.
During sunrise and sunset, sunlight has to pass through more atmosphere than it does during the day when the sun is higher in the sky.
The extra atmosphere scatters the shorter wavelengths like blue light and violet light.
If the path is long enough, it can filter out all of those colors. That is why we don't see those colors in a sunrise or a sunset.
After that, we're only left with the longer wavelengths of light like red, orange, and pink light. That is why we normally see those colors in a sunset.
If you want even more intense sunsets, you'll want more molecules in the air to help scatter the other colors of light. Dust and smoke from wildfires can help with this, but it needs to be the right amount. Too much will block the sunset.
On top of that, there are numerous other factors that can play into a good or a bad sunset. Those factors include the number of clouds and how high in the sky they are. But today we were just focused on the colors.
Enjoy the longer days!
- Aaron