Phenology Files: January 2023

Stunning Skies: The Science of Winter Sunsets & Sunrises

So far, January has given us several jaw-dropping sunrises. Here are a few that I’ve captured in my neighborhood over the last couple of weeks:

I’ve always thought that winter offers the best sunsets and sunrises. Maybe the vibrant oranges, purples, and pinks really stand out against the winter landscape – or maybe it’s just because the sunrises so late and sets so early that I am actually awake to catch them. While both of those reasons may hold some truth, it turns out there may be some scientific explanation as well.

The way that light enters and travels through the atmosphere, a process referred to as scattering, is what creates the colors of a sunrise or sunset. Light consists of different colors that have their own range of wavelengths with blue and green being the shortest. Since they are more likely to scatter and bounce, they can get filtered out at sunrise or sunset and leave behind the colors that create a cotton candy sky.

So what emphasizes this phenomenon in winter? Well, clean air is a big factor. Particulates and pollution in the air can make sunrise or sunset colors less intense because they further scatter light and less light makes it to the ground. Here, we are far from major pollution sources, wildfire smoke dissipates by winter, and winter winds keep the air circulating. Low humidity, another trait common in winter, also contributes to vibrancy.

As you well know, clouds are a near constant companion on the peninsula this time of year. Many of us get sick of the clouds, but they can reflect colorful skies back at us and make them even more beautiful. During winter, the Earth spins closer to the sun which means the sunset colors last a bit longer for us to enjoy!

Have a favorite sunrise or sunset spot nearby? Share it with us! Quite frankly, I love to watch it from my yard. I feel so lucky to live on the Olympic Peninsula! Even though I live within Port Angeles city limits, I can still experience nature and a clear sky from my home!

From the desk of Lexi Wagor, Community Relations Manager