PORTLAND, Ore. (KOIN) – Get ready for this conversation: “Sun what?” “Sundogs!” “Wait, did you say dogs?” “Yes!”

Dog in the sun! Photo by: Steve Lehl

No this isn’t about dogs that are relaxing in the sun. This Weather Kids lesson is about sundogs! Some may say they’re the best friend of atmospheric optics.

What are atmospheric optics?

Atmospheric Optics: These are noticeable patterns that you can see with your eyes. Also suggested as characteristics related to sight that are created from light in the atmosphere. For example, a rainbow (future Weather Kids lesson) or sundog.


Weekend Meteorologist Joseph Dames

There is a good chance that you have seen sundogs before! Have you ever been outside and seen a similar image to the one below? Well you have spotted sundogs with your eyes. These can best be seen about 22 degrees to the left and right of the sun. The best timing for this is when the sun is lower in the horizon in the morning or evening. These are bright patches of light that almost look like the sun. In fact, they also get the nickname, “mock sun” from time to time.

If you focus on the sundogs, you can see that they give a color gradient that is similar of a rainbow. The inside of the sundogs is red and the outside that is away from the sun is blue.

Don Feltham -Sundog Hillsboro

How about a sundog over Portland from just last week! Do you notice something that is common in these photos . . .


Sundogs show up because of the light refracting through the ice crystals of the thin clouds.

Refraction: Let’s call this the bending of light through a boundary. When it bends through a water droplet or ice crystal you get that visual element.

Sundog Photo by: Jose Julian Araya

Have you ever seen a prism? You can use that as a visual idea of refraction.

You may notice that there is a general halo around some of these images of sundogs. That halo is formed from the refraction of light through those ice crystals. The sundogs are an added atmospheric optic.

Bill Morrison – Optics

We have another lesson on atmospheric optics and cloud color here.