Atmospheric Phenomena

Rare Rainbows

We get a lot of rainbows here in the summer. I would even go so far as to say we get a lot of double rainbows. I've even seen more than one triple rainbow. But until this summer i had never imagined a quadruple rainbow. I see mysteries of the universe while i'm driving through the mountains and I dont' even stop, because i really need to get to some tacos.

One day on the way back from Glen Allen drove past 5 or 6 rainbows along the mountains, but when saw the rainbow above I immediately pulled over on the interstate near the Knik River. Half the people on the highway did the same thing. It was a dangerous mess. So of course i sent the pictures to all my friends but nobody had seen anything like it. I thought it was for sure a quadruple rainbow but it bothered me that the two sets of double bows were off center.

After a few weeks of not looking too hard I found out that it is a rare bow called a double reflection bow. This was great because i had sort of guessed what was going on. Behind the trees in the distance the Matanuska River flows into Cook Inlet so i figured the sun might be reflecting off the river and into a sheet of rain that might even be a different distance away than the other sheet of rain. I was right in concept but wrong about the where. Reflection bows usually reflect off a water body BEHIND the viewer!

From the website Atmospheric Optics:

The centres of reflection bows are at the same altitude as the sun - the anthelic point. This is the same distance above the horizon as the centres of normal bows are below it at the antisolar point. The normal bow and its corresponding reflection bow intersect at the horizon.

Reflection bows are usually brightest when the sun is low because then its light is reflected most strongly from water surfaces. The normal and reflection bows draw closer together as the sun gets lower. The source of the reflected light is usually water behind you, i.e. sunwards. It can be in front of you but then only the base of the reflected bow will be seen.

At sunset and sunrise rays travel through the lower atmosphere where they are scattered by air molecules and dust. Short wavelength blues and greens are scattered most strongly leaving the remaining transmitted light proportionately richer in reds and yellows. The result: Red Rainbows. 

Anti-Crepuscular Rays

Crepuscular rays appear to converge on the sun, anticrepuscular or antisolar rays converge in the opposite direction and you must have your back to the sun or sunset point to see them. They appear to converge towards the antisolar point, the point on the sky sphere directly opposite the sun. Like crepuscular rays they are parallel shafts of sunlight from holes in the clouds and their apparently odd directions are a perspective effect. Think of a long straight road, it converges towards the horizon but turn around and it also converges to the opposite horizon.   Crepuscular and anticrepuscular rays behave in the same way

Insane Ice Crystal Displays

One day i came out of my house to go run some errands and could not believe what was going on in the sky. There was a crazy double halo around the sun, some sundogs, and this other immense sized halo coming out of the sun and circling the whole sky. Inside the immense ring i could see faint arcs that intersected at the apex and continued onward outside the ring before they faded away.

Unfortunately i did not have the free time that day to go out and see if driving around would intensify or lesson the effect because i really was on my way out to go take care of some needed errands. So i took some quick shots from in front of my house, thinking it would quickly fade away. It lasted for at least 3 hours but i may have missed the peak by the time i saw it. It was a weird day with the smell of smoke in the air and wispy cirrus clouds overhead.

I have since learned that some of the the halos are a bit common but some of the ones i saw are exceptionally rare, occurring less than once a year and to see some of them is a once in a lifetime event!

 This is what it looked like outside my house.

A circumscribed halo (the oval) overlapping a 22 degree halo with the sun intersected by a great Parhelic Circle that covered a huge portion of sky.

The Parhelic Circle passes through the sun and is always the same altitude above the horizon. This one took up a huge area of sky that i could not fit into frame with my wide angle 17mm lens. More rare in this image are either Wegner or Hastings arcs bisecting the parhelic circle. These arcs are exceedingly rare events and apparently so hard to tell apart you may need a software enhanced negative image. Barely visible are diffuse arcs on the other side of the bisection. Even harder to see, but still there is a rare Supralateral Arc passing through the middle.

This enhanced negative clearly shows the two Wegner/Hastings Arcs bisecting through the Parhelic Circle at the Anthelion and continuing as Diffuse Arcs

 Changing the color temperature made the Supralateral Arc easier to see as a faint rainbow passing through the middle.

Millions of ice crystals with their vertical faces each mirroring the sun around the sky form the circle

Along the parhelic circle were a set of Sundogs.

And Finally, Light Pillars

This is not the coolest example of light pillars, but i'm at least impressed that i managed to get a picture of some only a few weeks after i decided i needed one for this blog. They are a lot cooler looking when they are on a clear night, and while rare, usually occur when it's much colder. The crystals for these were associated with some weird fog. These seem to have a faint horizontal element as well.

I tried driving to an area where there were more lights but this illusion was contained to a small area no wider than 1/2 a mile. In a good display even approaching car headlights will have pillars of light reaching skyward, and that can be disorienting.

"Columns of light apparently beaming directly upwards from unshielded lights are sometimes visible during very cold weather. Plate shaped ice crystals, normally only present in high clouds, float in the air close to the ground and their horizontal facets reflect light back downwards.
The pillars are not physically over the lights or anywhere else in space for that matter ~ like all halos they are purely the collected light beams from all the millions of crystals which just happen to be reflecting light towards your eyes or camera. The crystals producing the pillars are roughly halfway between you and the lights. When ice crystals float in the air around you, pillars (and other halos) can even be seen around streetlights a few metres away"