Friday, November 02, 2007

Halos for Halloween

My first day off this rotation, which coincidentally was the first day of Hallowhog, was not as productive as I would have liked. I had planned to give blood, get an oil change, get a haircut, and then prepare for the little ghosts and goblins who would come to my house that night, demanding candy. But several days earlier I had found that my house was without dial tone, and I really wanted to get it fixed. The earliest Verizon could get to it was October 31, which worked for me, though their scheduled appointment was for sometime between 8:00 AM and 6:00 PM. I called them that morning and was able to get this narrowed to between 2:00 and 6:00 in the afternoon. Since my blood donation was scheduled for noon, I figured I would be able to squeeze in the haircut and maybe even the oil change, depending on how long the blood thing took.

I had not counted on having four or five people ahead of me at the blood center. One delay led to another, and I did not get to the actual donation part until 1:03. The donation process also took longer than usual - when I used to go there on weekends, the blood donation staff often outnumbered the donors two to one, but now the ratio was more nearly the opposite. I was not done, refreshed, and back in my car until 1:50 PM.

Just enough time to get back to the house by 2:00. I didn't expect the service guy to be there at the stroke of two, but there were things I could do around the house while I waited. I watered my plants, fired up the furnace in preparation for a furnace dump (purging the rusty water from my steam radiator system), did a few other things, and then settled in to my re-reading of Harry Potter and the Deathly Hallows.

The service tech called at 2:48 and said he would be in Nanticoke in about ten minutes. A half hour later I was beginning to get worried. It seemed that every vehicle that drove by was a service truck, but none were from Verizon - until the one from Verizon showed up.

The tech looked a lot like Toby Keith, which I suppose would have meant something if I gave a damn about Toby Keith. We got straight to business, and once he realized my old house did not have an external access box, we went straight to my cellar. While we were heading down there, he pointed out that I did not have a inside wiring service plan (idiot idiot idiot, that was something you were supposed to deal with when you set up the service!), so any repairs to my inside wiring - if it turned out to be an inside wiring problem - would be quite expensive. But after a few minutes of line testing - which required the use of a broom to clear away a few decades of cobwebs from the vicinity of the wires - he determined that the problem was in the outside lines.

He repositioned his truck on the other side of the street and ran a ladder up the pole. I sat on my rocking bench on my front porch, non-functional telephone handset in my lap, and talked with my next-door neighbor about the weather while the phone guy did his thing.

It took the better part of a half-hour for him to locate and deal with the problem - a short in the main box. But once he was done, he said that he would also be installing an outside box on my house, just to make things easier if this ever happened again. He went into my basement again and drilled through the wall, coming perilously close to one of the brackets holding my new electrical service to my house. I stayed on the outside and fed a wire to him through the newly-drilled hole.

While I waited I happened to glance up at the sky and noticed that the wispy cirrus clouds were doing remarkable things. I like to take photos of clouds to use as potential future photo references for paintings. I ran back into the house to retrieve my camera from the kitchen and snapped this photo:

Crosshatched Cirrus clouds, 10/31/07
I was most interested in the crosshatched clouds in the middle of the picture. This suggested to me that there were winds at different altitudes moving nearly perpendicular to each other. But then I noticed the rainbow-colored patch on the left.
I zoomed in on this patch. A single cloud , located above the position of the sun in the sky, was showing a halo effect - a refraction of sunlight through ice crystals that are aligned just so. But something seemed odd. The bend to the halo seemed to be away from the sun.
More photos confirmed it: this halo was definitely not forming a ring around the sun. So what was it?
By now the phone guy was back out of the house, and couldn't help but notice me standing in front of the house taking pictures of the sky. "What are you taking pictures of?", he asked. And I told him. He looked up and said, "Well, that's definitely not a sun dog. Wrong place for it." And I agreed that a parhelion would not be in such a place - of course, everybody knows that! He went to work on the box on the side of the house.
After a while, as I stood out front showing the sky to the neighbors, the phone service guy called out from the side of the house. "There's your parhelion!" Clouds had aligned themselves just right for a sun dog to appear between my house and my neighbor's house.
The halo above us gradually resolved itself into a segment of a circle which, if extended, would form a ring around the top of the sky. "Upper tangential arc!", I called out, realizing that the phone tech knew a bit about atmospheric optical phenomena. "Or circumzenithal arc! I'm not sure. I'm gonna have to look it up!"
And look it up I did, in my trusty copy of Light and Color in the Outdoors by M.G.J. Minnaert. I now believe this was the circumzenithal arc, as described in section 165 on page 218:

One of the most beautiful halo phenomena! Of fairly frequent occurrence, it is a vividly colored arc parallel to the horizon and showing the colors of the rainbow.

Closeup of the colors of the circumzenithal arc
The arc persisted for a while. It brightened at first and then faded. The geometry of the refractions was very specific: I called my mom across town, but less than a mile away she could not see it at all.

While all this was going on I remembered that my original intent was to get reference photos for paintings of clouds. But I laughed when I noticed the cloud on the right in the photo above. Here is the photo, from October 31, 2007...
...and here is the painting, from March 26, 2007, more than seven months earlier. So maybe I don't really need those reference photos after all!

1 comment:

whimsicalnbrainpan said...

How beautiful!

Thanks for sharing those great pics!