Q&A: Sunset vs. Sunrise

Question: We got an assignment in science class to write to a real scientist and ask a real question. My dad reads your blog and he said I should ask you, so here’s my question. You have so many great photos of sunsets on your blog, but no sunrises. Are sunsets just more colorful? — EB, Denver, Colorado

Answer: In honor of your question, EB, I hereby post the first ever sunrise photo to run in Sky Lights. And this is my 484th post. As you can see, this is a very colorful sunrise and they’re not at all uncommon. But statistically, in most locations, sunsets are more colorful because of how the air changes while the Sun is up.

Around urban areas, smog and particulates generated by traffic and commerce accumulate over the working day. That can add a lot of color by the time the Sun sets. Overnight, most of this pollution settles out or drifts away, so the air at sunrise is generally cleaner and more transparent. Here in the Arizona desert, dust blown from the dry soil (and smoke from California wildfires) can add to the effect any time of day.

Extra particles in the air produce colors in the sky because of two related phenomena: Rayleigh scattering and atmospheric extinction. Follow those links to learn more.

I guess the main reason I hadn’t already posted a colorful sunrise photo is a matter of schedule. Thing is, I don’t often get up before sunrise, and when I do I need a few cups of coffee before doing any photography. However, I’m virtually always awake at sunset — I end most workdays on my deck reading, camera ready if needed. So in my case, there’s a “photographer bias” toward sunsets over sunrises. But that’s just me.

This sunrise was photographed a few years ago, when I had to rise early to catch a flight to Wisconsin. It was just too beautiful not to photograph. So I went back into the house, grabbed my camera, and took a few shots. This was the best of them.

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Earth's Water Resources
Q&A: Meteor Trails