Wednesday, June 20, 2007

Sun Halo

On the 10th we saw something in the way of atmospheric optics...



...but it was very difficult to photograph. (Still no new camera yet, by the way. I remain frozen by indecision.)

Edited portion follows


The pictures were perhaps too subtle. I've added this over-enhanced photo. (Can you see me now?) The arc is a pale upside-down rainbow that begins 2/3 down the left side of the picture and sweeps over to the larger cloud mass at right.
Maybe you had to be there.




I couldn't identify which particular effect this was. 22° halo? 46° halo? Something else (Supralateral arc)? I suspect a 22° halo, mainly because it's the most common. But this wasn't as bright or as colorful as those sound.



Here is the same picture with the contrast enhanced. It looked so much cooler in person.

The details: Near Oneonta, Alabama. Around 10:00 - 11:00 am, sun at about 45° angle to horizon (so, not a Supralateral arc then, since they only form at 32° or less). With the camera at 35mm I could not get them both in the picture. (But I wasn't too far from it, which also makes me think 22° halo.)

I read and read at the wonderful Atmospheric Optics web page. (I kept confusing myself.) I posted on a weather forum but got no answers.

Note to self for next time:
Edge of halo one outstetched hand (at arm's length) from sun: 22° halo.
Two outstretched hands: 46° halo.

Also difficult to photograph was this recent cloudbow.



Oh the fuzziness.

7 comments:

DeeMom said...

Could it be an iridescent cloud? That might explain the optics

http://www.atoptics.co.uk/droplets/irid1.htm

Mark said...

Those are actually not bad photos, given the difficulty of photographing that type of thing.

pablo said...

Clearly you can see with a sort of supervision that we mere mortals don't have. That's why you're my Queen!!!

I remember seeing a blue cloud amidst a bunch of white clouds on a trip back from Iowa years ago. I always wondered why one cloud could be a different color (or any color at all besides white).

Rurality said...

Deemom, no they were definitely arcs. I wish I'd had a polarizing filter. I have the idea that these pics are a bit too subtle.

Mark -- maybe you have to know what you're looking for?

Pablo, you can't see them? Really? I swear it's not The Cloud's New Clothes or some such.

robin andrea said...

We saw a halo quite like this one just yesterday in Port Townsend. I tried to photograph it as well with not so satisfying results. This sun halo produced a second ring. I really wanted to capture that, but the lighting is just too hard to figure out how to make it work. You did a good job.

Rurality said...

A second ring? That sounds really interesting!

kris said...

Great photos - I don't know the technical stuff about clouds or cameras - but love the posted results!