Double Solar Halo Spotted June 8 In Maine: 22 and 46 Degree Angles Explained

June 8 2020

A truly magnificent view was in the sky over Winthrop, Maine today. Marjorie Lewis was visiting from Fredrick Maryland and spotted what looked like two rainbows in the sky. What she captured was the very rare double solar halo.

What is it? This is created by sunlight passing through ice crystals high in the sky. While the spread of the colors is the result of a prism like phenomenon, it is different than that of a rainbow. I’ll explain below.

Solar Halo

If you have every seen a ring around the sun, that is a dollar halo. It is sunlight being refracted through ice crystals in the high thin cirrus clouds. This is often a signal of a change in weather, perhaps rain in the next day or two.

Seeing one ring around the sun is actually pretty common. Although I do get photos every year from people who have just noticed for the first time.

To see two rings, this is a special event!

 

Angles For The Halos

Primary Halo at 22º

Ice crystals in the cirrus clouds are hexagonal, or six sides based on the structure of water when it freezes. To get that rainbow in the sky, sunlights needs to pass through at a 22º angle. This will allow the ice to act like a prism and spread the light colors apart for our viewing. This is the most common showing.

 

Second Halo at 46º

When light can pass through the ice crystals at 46º, this can also work to spread the the light apart. Since this is a larger angle, the light will spread the colors wider and OFTEN it will be dimmer.

 

Blueprint To See The Double Solar Halo

 

Rainbows In The Sky

These are not rainbows since it is with rain falling. I’ll explain the rainbow below.

All of these are refraction in ice crystals. These include the solar halo, sun dog, and circumzenethial arc.

 

 

Circumzenethial Arc: My Video From July 22, 2018

 

 

Compared to rainbows:

Rainbows are when sunlight is refracted  through falling rain. This happens when the sun is behind the observer and rain is in front.  The light refracts AND reflects inside the droplets.

When there is a double rainbow, the light passes through and reflects twice inside the droplets. With a double rainbow, the secondary arch shows the colors in reverse due to that extra reflections.

 

This photo from Alina Costabile was on Sept 30, 2011. This close up show the reverse order of the colors with the secondary arc.

 

Double Solar Halo 

One more view of the double solar halo and we can see the colors are in the same order. Red is on the inside of the arc, closer to the sun for both. The secondary arc is spread out farther, and less bright.  This is due to the light passing deeper through the ice crystals at the longer 46º angel to spread out farther.

Thanks agin to Marjorie for sharing this, and giving me a project today.