I have many photos sent to me each day on my Facebook page, Twitter and by email. Today most of the photos were of the sundogs seen this morning and this afternoon.

Here is the short answer as to how they form. Sundogs are the “rainbow” like lights on either side of the rising sun or setting sun. The sun needs to be low in the sky. So that means the best time to view sundogs would early in the morning or late in the afternoon. There also needs to be  high thin clouds (cirrus) overhead. The cirrus clouds are made of ice crystals.  The crystals refract the sun’s rays.

Here is a link for the more technical answer to how they form. Click here

Posted under Optics, Photo

The photo above was taken by Dan Gingerich. It is the Hot Shot photo at 5 pm today. It was taken in Decorah. I was not sure exactly why the shadow looked the way it did in the sky. When it comes to atmospheric optics the #1 source is Les Cowley. He runs a GREAT web page. http://www.atoptics.co.uk/ 

I have asked him questions before and he ALWAYS has the answer. So I went to him again to help me out. Here is what he had to say about the photo above.

Cloud shadows and rays can, like these ones, be very counter intuitive! 

The dark shadows look like they are pointing upwards but in reality they are angled downwards – all shadows cast by the sun must go downwards.      

There is a thin layer of hazy cloud _below_ the top of the towering cumulus.    The sun is casting a shadow of the cumulus cloud onto this lower layer.   We see the shadow through the other side of the lower cloud layer ‘screen’.     The shadow looks above the cumulus cloud simply because the shadow is closer to the camera.   See the diagram here: http://www.atoptics.co.uk/atoptics/rayim13.htm

Posted under Optics

The photo below was taken by Jenn Palmersheim Sunday evening.

The ring around the moon is called a halo and since it is around the moon it is a Lunar Halo. The reason for the halo is because there are high thin clouds moving between Earth and the Moon. Click here for more information  halos.

Posted under Optics

The photos below were taken on Tuesday May 15 during the afternoon. I contacted Dr. Les Cowley (an optics specialist) to explain the photos below. Here is what he had to say.

The first 2 photos are ice halos –  circumhorizontal (preferred circumhorizon) arcs.    

There is a widespread Internet myth that these are very rare and on those sites they are erroneously and misleadingly called ‘fire rainbows’.   They are not rare.   In the US you can expect to see several each summer if you watch the skies They are formed by plate crystals in cirrus.   More about them in this site section:
http://www.atoptics.co.uk/halo/cha2.htm

Taken by Kevin Bublitz

Taken by Yeni Klemesrud

Here is what Dr. Cowley has to say about the photo below:

This photo is much more interesting and its a relatively rare shot.

The camera is pointing almost straight upwards.   The colored arc at top is the common 22 degree halo around the sun ( http://www.atoptics.co.uk/halo/circular.htm ).   The mid-frame white circle is another ice halo, the ‘parhelic circle’.   This halo circles the sky always at the same height as the sun.   When the sun is high – as here – it shrinks in size but remains centered on the zenith.   See:
http://www.atoptics.co.uk/halo/pchigh.htm

And a section about the parhelic circle - http://www.atoptics.co.uk/halo/parcirc.htm
Taken by Yeni Klemesrud

Click here to check out the optics web page that is run by Dr. Les Cowley.

Posted under Optics, Photo

NASA’s explanation: A lightning discharge in a thundercloud can temporarily change the electric field above the cloud where charged ice crystals were reflecting sunlight. The new electric field quickly re-orients the geometric crystals to …a new orientation that reflects sunlight differently. In other words, a lightning discharge can cause a sundog to jump. Soon, the old electric field may be restored, causing the ice crystals to return to their original orientation.

Posted under Astronomy, NASA, Optics, Video

If you have photos of fall colors you would like to share…send them to schnack@kwwl.com. Put FALL COLORS in the subject line. I will put all of them on the blog and will use some on the evening newscasts this fall. There is a link at the top of the blog “Fall Colors” that has the latest updates on how the leaves are changing around the Midwest.

Posted under Fall Colors, Optics

If you have photos of fall colors you would like to share…send them to schnack@kwwl.com. Put FALL COLORS in the subject line. I will put all of them on the blog and will use some on the evening newscasts this fall. There is a link at the top of the blog “Fall Colors” that has the latest updates on how the leaves are changing around the Midwest.

Posted under Hot Shots, Optics

If you are a fan of atmospheric optics you will love this photo. This rare photo was taken on October 30 in Kittilä, Finland by photographer Sauli Koski. The left photo is the original photo the right photo is labeled.
 
You can find more information about this photo here.

Posted under Optics

One rainbow is nice to see and a double rainbow is twice as nice. Imagine seeing a triple rainbow. It is rare but not unheard of. Daryl Pederson of Anchorage, Alaska, saw one on Sept. 20th:

Click here for more information on this photo and multiple rainbows.

Click here for more information on reflective rainbows.

Posted under Optics

You are probably saying what in the world is a Circumzenithal arc. Click here for more information and some more cool looking photos.

Posted under Miscellaneous, Optics