K-Squared Ramblings

Rainbow Feather Cloud

On my way back to work after lunch today, I looked out the window and saw this feathery wisp of cloud with a clear rainbow pattern running from red at the the top to violet in the middle, then turning plain white below.

As I drove south, the colors moved down the cloud, disappearing entirely by the time I got back. By the time I could safely snap a photo, it was already more or less midway down the cloud.

I believe it’s a fragment of a circumhorizon arc, judging by the description:

Look for a circumhorizon arc near to noon near to the summer solstice when the sun is very high in the sky (higher than 58°). It lies well below the sun — twice as far from it (two hand spans) as the 22º halo.

The arc is a very large halo and is close to, and parallel to the horizon. Usually only fragments are visible where there happen to be cirrus clouds.

We’re still 2 months from the summer solstice, but it was 12:38 PM DST (half an hour before true noon), and the sun was apparently near 70.6° high. (The site is aimed at UK visitors, after all.) It also looked too far away from the sun to be part of the 22º halo, plus of course the colors were more well-defined.

This also points out the should-be-obvious fact that ice crystals can still form in the upper atmosphere even when it’s warm — say, 90°F — on the ground, so there’s no need to limit halo-hunting to winter.

I recommend checking out Atmospheric Optics’ additional pictures of circumhorizon arcs, most of which are more complete than this one. Some of them quite spectacular and must have been really impressive to see live.

Stringy Clouds at Sunset

Sunset on Tuesday, March 25th, with feathery cirrus clouds and contrails. A faint sundog is visible as a slight brightening at the level of the sun, about 2/3 of the way across the picture.

Contrail Contrast

I had to get up early today, early enough that I could still see a couple of stars (or more likely planets, but I’ve lost track of where most of them are right now). When I got to work, I was treated to the sight of these contrails lit up against the morning sky. The rising sun was still behind the mountains, below the frame.

Look at the cloud directly above the contrail on the right, near the leaves. You’ll see a dark nearly-vertical line, which I initially took for a contrail’s shadow, possibly even the one below it. A minute or so later, though, it looked like it might have actually been another contrail, one not lit up by the sun and therefore darker than the cloud behind it.

Oddly enough, half an hour later the entire area was blanketed in fog.

Corona

Spotted this on Thursday, between rain showers. It’s a slightly distorted corona, formed by diffraction of sunlight around cloud droplets, splitting the spectrum and producing rainbow-like colors. According to the Atmospheric Optics site, the distortion indicates that the droplet size varies across different parts of the cloud.

This was shot through a window, and I’m 99% certain that the straight line running down the middle of the darker foreground cloud is a reflection from inside the room.

Golden Lining

Friday, September 28:

Adding to the mish-mash of photo sources on here, this is a still frame from a video clip taken out the window of the car. It wasn’t supposed to be a video clip, but my camera has a sliding switch for selecting photo/video/review, and it has a tendency to shift while in a pocket or bag. *grumble*

Cobweb-cloud sunset

I stepped out of the office last Thursday (September 27—it was a good week for interesting late-afternoon skies) and saw this view to the west.

The clouds glowing as if from within, and the curved bands as if the whole set had been dragged across the sky, reminded me a bit of pictures of reflection nebulae.

Sundog

Spotted a sundog last Wednesday (September 26), about an hour(?) before sunset.

At least, I’m pretty sure that’s what it was, given the positioning, the brightness, and the reddish coloring on the end nearest the sun. The sharp edges of the reflecting cloud (a fragment of a contrail?) make it look a bit odd, though, like someone cut out a chunk of sunlight and pasted it into the sky.

Here’s a closer view from about a minute later.

I was following my usual photo-while driving method of pointing the camera in roughly the right direction, click the button a bunch of times, and hope a few shots come out. (Hooray for digital cameras, where you can delete a bad photo instead of wasting film!)

Rays of Light

Every once in a while, I manage to get a decent shot with my cell phone camera (currently a RAZR V3T).

Taken August 4 at 6:20pm. Cleaned up slightly to remove a digital glitch just above the cloud.

Invasion of the Lenticular Clouds!

I wasn’t expecting to see more after my last post on lenticular clouds. As I said, they’re (usually) rare in this area. But as I left the office Friday evening, I pulled onto the freeway and nearly freaked out at what I saw: A line of three smooth, layered clouds running above the ridge of the mountains to the north of Saddleback, and two more less-defined clouds picking up south of the peaks. I took the first exit and headed for a spot where I knew I could get an unobstructed view: a park in the Quail Hill area. (Knollcrest, I think.)

Click for a larger image

It was near sunset, and I was in a hurry to get some photos (not to mention a better chance to look at them!) before the light faded. You can see that the sun had already dropped behind the hill on which I was standing.

Click for a larger image

If you look at the horizon in the wide view, near the left at what looks like the base of the hills, you can see the orange balloon at the Great Park. I’m fairly sure they’d stopped taking people up by then, though I did see it airborne during my walk at lunch.

I’ve enhanced the contrast on these next few images, all cropped from the same photo to show close-ups (relatively speaking) of the three clouds:

I’m going to do something unusual here, and post an original-resolution copy of that contrast-enhanced photo, just ’cause it’s so cool. It compressed really well, to 170K, but beware—it’s still a 2,567 pixel–wide image.

Into the Storm

Here’s a photo from the same April rainstorm in which we spotted the red rainbow at sunset:

This was taken about an hour earlier, driving up the 405.

Lenticular Cloud Over Irvine

One of the problems with photographing clouds is that you can’t run and grab a better camera. You have to shoot with what you have, or they’ll change configuration and quite possibly look completely different by the time you get back.

As I left for a late lunch today, I saw a set of half-discs stacked together, with a long trail stretching off to the left. We don’t see lenticular clouds that often in this area, so I stopped the car, grabbed my cell phone and aimed it out the window.

The Santa Ana Mountains are hidden behind the office buildings, and are probably the cause of the cloud formation.

Unfortunately, the detail isn’t that great. I tried to enhance the image a bit, but it looks like the brightest parts of the cloud overwhelmed the sensor. This is at the camera’s native resolution:

Update: Spotted some more interesting cloud formations later in the afternoon. Read the rest of this entry »

Contrail Shadow

With any luck I’ll finally post about last week’s trip to Las Vegas soon, but meanwhile, here’s something interesting that we spotted a couple of times on the drive back: The shadow of a contrail against the sky.

Here’s what it looked like, as the camera saw it. Actually, it was much more visible at the start. It faded considerably in the time it took to get the camera out and snap the photo.

And here it is with the contrast enhanced. You can see a dark line extending across the sky from the end of the trail down to the lower left. The sun was at the upper right, almost but not quite in line with the trail at that point.

Atmospheric Optics has a huge collection of cloud shadows, rays, rainbows, ice halos, and more, including a diagram of how contrail shadows work.

Cloud Window

This morning I looked north and saw a narrow band of mountains sandwiched between two layers of clouds. The first place I could stop to take a photo, the lower layer was mostly blocked by hills, but you can still see it.

Click to enlarge

As a bonus, this turned out to be nearly the same shot as one of the photos I posted under Snowblogging four weeks ago (reposted here):

Click to enlarge

The lighting isn’t as good in today’s photo, since it was overcast, but you can really see the effect several weeks of one-day-a-week rain have had on the hills. They’ve gone from brown with splashes of green to green with splashes of brown!

Sunrise, Sunset

The first photo is from Wednesday morning around 8:00. Katie took it on our drive to work. There’s actually another shot that shows more of the sky, but this one is more striking. The second shows tonight’s sunset as seen from the Metro Pointe parking lot. Yes, it’s a freeway in the foreground, but the sunset itself was incredible. Both thumbnails are linked to larger copies of the photos.

Finally, here are some vaguely lenticularish clouds I saw looking north at sunset on Friday. This one’s full-size already:

Cloud Cover-Up

Today was a reminder that just having cloud cover doesn’t necessarily keep things cool. We’ve had occasional wispy clouds at evening, and at one point some serious cloud cover closer to the coast, but today was hazy and overcast all day—and it was just plain muggy.

Eh, it’s only early August. It’ll get hotter (and occasionally muggier).