Tag Archives: sun

Contrail Shadow, Halo, Haze & Sundog

While driving around lunchtime, I saw an airplane pass overhead, its contrail casting a shadow on the thin cloud layer below. I had my camera handy, and was stopped at an intersection, so I snapped a couple of shots. As often seems to happen, the first, haphazard one was the best.

The diagonal line extending down from the sun is, I believe, a sun pillar-like effect in the trails left by the windshield wipers. Also: Unless I’m mistaken, you can just barely see the edge of a halo in the feathery clouds at bottom center. It’s the slight reddening.

A few hours earlier, I saw this:

I glanced out the window while changing lanes on the freeway this morning & noticed the bottom edge of this halo. By the time I had a chance to stop the car and really look, the lower arc seemed to have disappeared, but the left side was sharply visible – as was a sundog. I rolled down the window and snapped a couple of photos while waiting for the light to change. Unfortunately, I couldn’t position anything to block the sun, so the exposure isn’t all that great.

By the time I reached my destination and parked, it had all faded except for a slightly bright patch in the clouds to the left.

Halo Triplet

While walking to lunch today, I spied a fragment of halo above the sun. (Whenever I notice a really thin layer of cirrus clouds, I always try to find an opportunity to block the sun and look for halos.) I tried to get a couple of shots with my phone, and figured I’d try enhancing them when I got home.

What surprised me is that the halo was not only still there after lunch, but clearer. On the way back, I stopped in several places with a building, or a sign, or a tree blocking the sun. The curve seemed too shallow to be a standard circular halo, so I wondered what I was actually seeing. Then I realized there was a faint halo inside the brighter curve, the two fragments meeting above the sun and splitting like diverging roads.

Then I noticed the sundog.

Halo Triplet

Three distinct sun halos. Not complete, and far from the clearest display I’ve seen, but certainly the most complex.

The brightest part appears to be the top of a circumscribed halo, which varies in shape from oval to kidney-bean depending on how high the sun is. You can just see the 22° circular halo branching off below it. Off to the right is a sundog.

It’s too bad I only had the phone, but it did manage to catch all three halos. I fiddled with the contrast a little to make them clearer, but they are visible without it.

And to think I saw this from the middle of suburban Southern California!