Tag Archives: sun

Rainbow Cloud

Circumhorizon arc fragment, halo and contrail

I noticed the halo around the sun as soon as I walked out the door for lunch on Thursday. The rainbow cloud? That appeared as I walked past a building. I saw it as soon as the southern sky came into view again.

The colors got more intense over the next few minutes, and I kept taking photos until my phone locked up. I stood there watching the colors intensify, then fade, while I pulled out the battery and waited for the phone to reboot.

A man who’d been sitting nearby, buried in his phone, looked up wondering what I was taking pictures of. He’d never seen anything like it before, and wondered what it was, and fortunately I was able to answer.

At the right angle, ice crystals in a cirrus cloud refract sunlight to produce a feathery rainbow effect. The circumhorizon arc runs parallel to the horizon, and while it can be long, it’s usually only seen in fragments like this. I’ve only seen a few of these myself, and it’s been years since I’ve seen one this intense. I took this photo through my polarized sunglasses, but the colors were bright even without them.

When my phone froze, he offered to send me one of his pictures just in case mine hadn’t actually saved. Fortunately they had, and I actually posted to Flickr several hours before his message made it through the cell network.

Within a few minutes, the cloud had drifted out of alignment, and the colors had faded completely.

An hour later, on the way back from lunch, I noticed a longer patch in a smoother cloud layer, but it was faint enough that I could only barely see it with my sunglasses on. Without them, it faded completely into the glare.

If I’d had my better camera with the zoom lens, I would have gotten some better shots of just the bright cloud. Then again, I wouldn’t have been carrying it with me to lunch, and the effect was gone in the time it would have taken to run back in and get it. So it’s probably just as well I stayed and watched instead.

Funny thing: I posted a cropped view on on Instagram featuring just the arc fragment and contrail. When I went back to look at the #rainbowcloud tag last night, I found no less than SIX other photos of what was clearly the same cloud at various points in its five-minute lifetime!

Missed Transit

I had no luck viewing the Transit of Venus. I didn’t have time to find and meet up with any sort of viewing party that might have a telescope or other equipment, and I’m kicking myself for not having tracked down a set of eclipse glasses of my own, so I was left with a handheld pinhole “camera” made out of a cardboard gum package. The clearest image I could get with that was about 1/4″, too small to see the tiny speck moving across the sun. (Though I could see the cloud bank the sun was setting into about the point that I gave up and went inside.)

Oh, well. I can’t be too upset, since I got to see a great solar eclipse two weeks ago. And there are plenty of places to watch online and find pictures.


Photo from Astronomy Picture of the Day.

Feathery Not-a-Rainbow Cloud


Feathery Not-a-Rainbow, originally uploaded by Kelson.

I saw this amazing circumhorizon arc around 1:30 this afternoon. I had just crossed the street while walking to lunch when I looked up, saw it…and walked back to the office to get my camera!

Lesson learned: always bring the camera!*

It started out as just a couple of small segments, but as the clouds drifted into position it quickly grew, and at its strongest it was just long enough to fill the field of view on my camera. There were also a couple of fragments of a 22° circular halo visible at the time.

The whole thing had vanished by 1:50, as the clouds drifted out of alignment, though I did see a more complete circular halo later on.

It looks like a sort of straightened-out rainbow, but it’s actually caused by ice crystals. If the right type of crystals cover the entire sky, this will actually stretch in a circle all the way around the sky, parallel to the horizon.

They’re a lot less common than the 22-degree halos. I’ve seen and photographed a ton of those over just a few years, but this is maybe the second time I’ve seen something like this. Fourth if you count the two feathery fragments I’ve seen.

At times like this, I really wish I had a DSLR, but the point-and-shoot will do in a pinch.

*On the other hand, when I went back, I pointed it out to a couple of people at the office who are into photography, since it was visible through the windows on one side of the building. One of my co-workers has a digital SLR and carries it with him, so he went outside and got some great shots. If I hadn’t taken a late lunch and chosen to walk anyway and been in the habit of looking for halos and forgotten to bring my camera, chances are no one in the office would have seen it.

Update (May 17): I just discovered that there are people who think these clouds are connected to earthquakes. No, they aren’t. They’re caused by ice crystals refracting sunlight, just like most halos, and have been seen in many places that didn’t have earthquakes.

Halo Mosaic

Halo Mosaic
Halo Mosaic, originally uploaded by Kelson.

A mosaic of four photos I took this afternoon of a full 22° halo around the sun. It was extremely hazy, and the halo was almost impossible to see without sunglasses because of the glare. I actually stopped the exposure down in order to get the halo.

A few minutes earlier (and a few miles away) I also saw a faint fragment of a circumhorizontal arc. Oddly enough, it was the same time of day, time of year, direction of the sky, and stretch of road as the last one I saw! If I drove that stretch of road regularly, I wouldn’t be so surprised, but I’m only rarely in that area at lunchtime.

Update: About a month later, I saw a really clear circumhorizon arc (or rainbow cloud)…from my office building’s parking lot!

¾ Sun Halo

I spotted a great 22° halo around the sun this morning, almost by accident. There was a reflection in the rear window of the car in front of me that looked like it could be a distorted contrail or it could be a distorted halo. Once I parked, I looked — and there was this clear halo, almost 3/4 of the circle. The missing quadrant was to the lower right, so I just framed this to get as much of the visible part as I could.

It wasn’t really this blue. The G1 tends to make images in daylight a little extra blue, and seems to have really gone overboard on this one. I’ve got to remember to bring the regular camera with me more often!