Category Archives: Clouds

More sunset

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We walked out of a store late Tuesday evening and saw a wonderful sky.

sunset_6_28_16

I made these shots bigger than I usually do, so clicking on them should give you a larger image.

As usual, I had only my iPhone, so this is another phone shot. This sky deserved a panorama, but unfortunately when I started the pano on the left, it exposed for a relatively dark sky, which resulted in gross overexposure for the brighter parts of the sky. It’s a shame the shot has to include parking lot lights, but there was no way to avoid them or the power lines in the foreground.

This was what we saw a few minutes later on Huffaker Road.

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I couldn’t get enough of the sky to show all the different types of clouds that were present. When you see this kind of sunset, or any type of landscape, your mind combines all the views into an overall mental image. You can see part of the scene through a gap in the trees are you drive, and another part a few hundred yards down the road. Your mind puts it all together and you can imagine what the entire sky looks like. Trying to get that mental image into a camera can be frustrating.

A few days ago we went up to the top of the mountain to see whether we could get a better view of the sunset. Up there the sun was setting in line with the ridge, so we could not actually see the sun. I thought maybe there would be a better view if we went down into Texas Valley. Tuesday evening we did that. There isn’t. The trees are so close to the road that they obscure the sky.

Thursday sunset crepuscular rays

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A quick grab with my phone camera caught this sunset Thursday evening as we drove home from picking up some prescriptions.

crepuscularrays

This type of photo is hard to get right because of the high contrast. The phone did a reasonable job, but it had trouble capturing the shadows of the some of the clouds.

We drove up to the top of the mountain hoping to get a better view, but the sun was setting along the ridge, so it was pretty much hidden. The clouds were gone by then anyway.

I think we could get a better view of the sunset if we went down into Texas Valley. Maybe we’ll try that one day.

Green and black, and blue and white

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Sometimes you have to look up as well as down.

Here are some of Zeke’s favorite roadside foods.

greenblackberries

They’re a little blurred, which I will blame on Zeke and Sam pulling on me while I tried to take a picture. These are unripe blackberries. Zeke checked them but they were too green even for him. This was Tuesday evening.

On Wednesday, we looked up instead of down.

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There were lots of cirrus unchains (this is a link to a source other than Wikipedia, for a change), or mare’s tail clouds. They were changing very quickly, even as we walked along the road. When we got home I saw these from our back deck.

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They were slowly fading to pink. I sat for a few minutes, but the sky was changing so quickly that they were gone before the setting sun could paint them.

The sky on Wednesday seemed particularly beautiful to me because we had some good news earlier in the day. A second flooring contractor came out and measured for tile and hardwood. He sounded knowledgeable, even about electrically-heated bathroom floors. He gave a reasonable estimate for the work, less than I had expected. And, what’s more, he said he could almost certainly start by May 23. That will work out almost perfectly, because I hope the interior painting will be done by then, and, maybe, just maybe, the power and heating/AC as well. The timing was very good, although it’s clear at this point that we will not be in the house by the end of May. However, I am willing to bet (a small amount) that we can be ready to move in by the end of June, assuming our buyers’ bank is able to move reasonably quickly. It even seems that I will be able to do the trim work in the new house.

I’m pretty happy about things right now, but don’t tell Fate about that.

 

Sunset in the east

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We happened to look outside at just the right time to see the entire world bathed in a warm, yellowish glow. I grabbed the camera and went out onto the deck.

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As I stared up at the clouds, I noticed a bright silver speck moving silently and quickly across the sky. Something about it seemed unreal.

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The jet is barely visible slightly below and to the left of center here. I zoomed in a little to make it more visible.

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The passengers in that silver cylinder didn’t realize what kind of show they were putting on.

The show lasted a few minutes and then it was gone.

 

Distrail

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We saw some nice clouds when we took the dogs out for an evening walk Wednesday.

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There were some waves and a couple of interesting features associated with the passage of high-altitude airliners. Just to the left of center there are two dark, linear features that are probably, but not certainly, contrails. If that’s what they are, they are probably old (where old means more than a few minutes). They look dark because we’re looking at the under, shaded side. They may not be contrails at all, just linear cloud features.

Just above them, however, is what appears to be a negative contrail, a linear feature of apparently clear air within a cloudy region of the sky. This is more likely to be an artifact of the passage of an airliner. A negative contrail is also called a distrail, or dissipation trail. Here’s a little closer look.

distrail

In searching around for an explanation for distrails, I found at least two. One is that the warm exhaust of a jet engine warms the air in the cloud, causing existing cloud droplets or ice crystals to evaporate. A second is that the small particulates in a jet exhaust become condensation nuclei which cause large enough droplets or ice crystals to form that they precipitate out of the cloud, leaving behind a clear region. The website with this particular explanation alternatively attributes the effect to the turbulence created by the aircraft’s passage causing greater condensation and precipitation. Other explanations don’t mention turbulence; I think it’s possible that under the right conditions, turbulence might cause a wake of sorts to appear in a cloud that looks like a negative contrail. I think that’s a different phenomenon from the particulate-condensation nuclei-precipitation explanation.

I think the second explanation (particulates-condensation nuclei-precipitation) is probably closer to right, and the warm air-evaporation explanation is wrong. My reasoning is that the same conditions that cause a condensation trail to form are being blamed for an evaporation trail. The warm (or hot, if you will) exhaust of a jet engine very quickly cools as the gases expand, which causes the water vapor it contains to condense, thus forming a contrail. I can’t think of a way that adding water vapor to air will cause evaporation.

The accuracy of the second explanation is bolstered by accounts of seeing virga or falling ice crystals from the region of the distrail.

A third explanation includes some atmospheric optics along with the particulates-condensation nuclei-precipitation process that may or may not be necessary to the explanation of distrails. It relies on optical properties of ice versus water as well as on precipitation. If anyone is interested they can check out the site, which some readers are already familiar with.

On other days in other skies, I have seen what looks like a negative contrail, but these are usually a visual effect. What looks like a negative contrail in those cases is actually the shadow of a higher contrail falling onto a lower cloud deck. It’s sometimes hard to tell the difference because the lower cloud deck can hide the higher contrail, so all you see is a dark trail through the clouds that looks a lot like a view through the cloud to clearer sky.

In this case, I think what Leah and I saw was actually a distrail.