11 June 2009

A Salute To The Cloud Appreciation Society (Don't laugh I'm a member!)

Posted by Dan Satterfield

Yes there really is such a thing and you can join too. I warn you, a membership card will mark your final descent into geek-dom. So clean the screen on your Mac, and dust off your entire collection of Doctor Who episodes, and accept the fact you’re a geek and be happy about it. I am!

There is actually some big news in the cloud world as of late. There is a new one! Not world, we still have the same one, and it’s ecosystem is in a very iffy state. What we do have is a new cloud type. Maybe.

The Royal Meteorological Society is working with the founder of the cloud appreciation society (CAP) to get it recognized officially by the World Meteorological Organization (WMO) of the UN. I think they have a pretty good chance too. I myself have seen them and could not identify them either! They are very beautiful and memorable.

The working name is ASPERATUS. Latin for rough and they do indeed appear rough! You can see an example of the cloud on the image below. Click to go to the CAP website.

Asperatus? Is the cloud of the month at the Cloud App. Society.

Asperatus? Is the cloud of the month at the Cloud App. Society. Image is hyperlinked.

Cloud types are not that hard to learn. Here is an easy way to do it.

4 main categories:
1. Low 2. Middle 3. High 4. Tall
Each of these categories can have flat clouds or puffy clouds. Flat clouds are status. Puffy are cumulus. Middle clouds have the prefix Alto. High cloud has the prefix Cirro. There is only one tall cloud, a cumulonimbus. Commonly called a thunderhead and it is indeed likely a thunderstorm, or about to be one! Sometimes you will see a low cloud that seems to be a bit of stratus and cumulus together. Call it stratocumulus and you will likely be right.

One last thing. If it’s producing rain, add the word NIMBUS. Nimbus means rain cloud. As in cumulonimbus!  So a puffy middle cloud is an alto-cumulus and a high thin flat cloud is a cirrostratus. (I pronounce it cirro stray tus.)

Flying Saucer Lenticularis- Click image for more at Sci. Ray.

Flying Saucer Lenticularis- Click image for more at Sci. Ray.

My favourite type of cloud is a LENNY. Technically it’s an Alto-cumulus Standing Lenticularis. (ACSL). They sometimes look like flying saucers hovering over a mountain top. There was a great display around Mount Rainier recently. Lennies are caused by invisible waves in the atmosphere. As air rises and cools, at the top of the wave, it may condense and form a cloud. As it descends, the air warms, and the cloud disappears. The visible part of the cloud will tend to stand over one spot!


The link here is a great time lapse of these clouds from NASA.

Noctilucent Clouds- from NASA See description.

Noctilucent Clouds- from NASA See description. Click image for more.

There is actually another type of cloud. Very rare, and very high. So high, it’s in the Mesosphere between 45-80km high. At the edge of space itself.

Noctilucent clouds are seen usually in the polar regions after dark. They are so high, that they can be lit by the sun, after it’s totally night at the surface. NASA is studying them with the AIM satellite. Check out the movie. I think I have seen Noctilucent clouds once, but I cannot say for sure.

The Mesosphere is the least explored part of our atmosphere. It’s extremely difficult to get there! You can pass rapidly through it on the shuttle heading into orbit, but you are there only for seconds. Too high for balloons and planes!

Some recent research is indicating that an increase in the appearances of these clouds may be due to climate change. While the troposphere is warming, the layers of the atmosphere above it are predicted to be cooling. That very thing is happening.

Clouds are the great leveler. Rich or poor, we can all see them and there is no charge. Those who live in the haze free areas of the world away from air pollution are the luckiest, and your chance of seeing Noctilucent clouds is much higher in polar regions. Lennies are very rare outside of mountain regions, but I have spotted them even here in the Southeast in winter.

These Cirrus aren't Near us. Click for details from NASA JPL.

These Cirrus aren't Near us. Click for details from NASA JPL.

Earth does not have a lock on clouds, with Venus covered in clouds made of sulfuric acid. Jupiter has clouds made of methane and Saturn’s moons Titan is also covered in exotic clouds. There has even been speculation that life might exist in the Jovian clouds, at just the right pressures and temperatures.

Yes, Mars has cirrus clouds!  They are made of ice crystals and look just like our cirrus.

I love clouds so much, I frequently show pictures, that viewers send me, on my daily weathercasts.

So look up in wonder every now and then!