Saturday, January 24, 2009

Day 25: They're BAAAaaack!!!! Sundogs!

As I was driving to work Friday morning, I slammed on my brakes, jumped out of the car, and shot this photo. Sundogs! Finally! If we have to have "seemingly interminably endless winter events" (aka 20 below weather), then I want SunDogs!

And they finally showed up. These look different than last years'. Last year, they almost looked like an eerie eye-in-the-sky. This year they look like a rainbow on either side of the sun. In this first photo, that is NOT the sun at the base of the rainbow. The sun was actually all the way to the right, almost at the base of the other side of the SunDog.

This is the view outside my window at work, so there's some reflection in the image.

I tried a polarizing lens to reduce the reflection, but it changed the exposure and coloring, and there's still some reflection.


Sundogs are formed by the refraction of light through hexagonal plate-like ice crystals whose flat faces are oriented horizontally and whose diameter is larger than 30 micrometers.

As sunlight passes through the crystals, it's bent 22 degrees. As a result, it looks like that light is originating from two spots on either side of the sun as well as from the sun itself.

Most sundogs and halos are white, but occasionally, some will show some color. That appears because white light is actually made up of many different wavelengths, or colors, of light. Each wavelength is slowed, and thus bent, at a slightly different angle than the next, which has the effect of separating the colors and making them individually visible. That's how rainbows are formed, but water droplets, which cause rainbows, are better refractors than ice crystals, and so the colors of a rainbow are more distinct than those of a sundog. With this ND weather, the water in the air is definitely NOT going to be droplets, and the ice crystals in the air are wonderfully suited to form ice crystals.

And so we have SunDogs! A slight reward for living on this frozen tundra. . . .

15 comments:

Becky Anderson said...

those are so cool! I have never even heard of Sundogs. I love the fist one, it really does look like a rainbow. It would be great to see the ones last year if you have pictures!

Jess said...

WOW these are awesome! I've never seen anything like this... I've seen northern lights before but never sundogs! WAY cool. :)

janett said...

Those are so cool! I have never even heard of those before!

Amy said...

Wow those are neat. I've too have never heard of them. TFS.

Inkspots said...

Very cool! I had not seen those before, let alone knew anything about them.

shirley said...

Cool! I learned something today. I've seen the rainbows emanating from the ground (like your first pic), but not the bright lights of your other pictures. Great pictures.

Lou said...

Well that was educational. We're missing out down here in the midwest. No sundogs here. Very cool shots. TFS!

Carol said...

I have never heard of this term before. But your photos are pretty cool.

Linnao said...

I'd never heard of SunDogs! they're beautiful!

Reds said...

Wow - love these! Never heard of sundogs - but will be looking for them now!

Jeanne said...

Very cool! I sort of remember you commenting about them last year and I'm happy you got such great shots this year!

Maria said...

These sundogs are so cool! I've never seen one in person, so the photos and the explanation are really appreciated. It makes me wish for a sundog right outside my window, right now.

Susan said...

Thanks for the lesson-very cool, I'd never heard of them either. =)

Bobbi said...

Learn something new everyday! These are gorgeous, I really love that color.

Barb said...

Colorful! They do look a little like the rainbow.