Can you capture a cloud

They lead to many, many very tiny particles. And because their sedimentation is so small, it takes a very long time for them to settle out of the atmosphere. So nucleation sites are preferred locations for the creation of water droplets and ice particles. So when the temperature is sufficiently cold, that happens readily.

And so they are buoyed up. They maintain their altitude to some degree by the larger scale atmospheric dynamics that cause upwelling of the atmosphere, so there is a sort of a 5cm per second general upward flow. So that helps preserve the particles at those altitudes. Gary and I have a colleague who is now deceased, but he did the really pioneering studies of noctilucent clouds, really, 60 years ago. He actually did stereo viewing from the ground, but his cameras were, of course, not what we have available to us now.

And he remarkably identified the key dynamics and the altitude and other things that were proven later on. But what is really exciting about this particular cloud layer is that it is very thin in many cases.

So it acts as a really spectacular tracer for really small scale motions in the atmosphere that would seem insignificant, but are really, globally, very important.

These are very high. So commercial aircraft fly at around 11 kilometers. Our balloon mission flew on a high altitude balloon at 38 kilometers, so three times higher. And it had to look up another 50 kilometers to see the PMCs above it.

My passion is small scale waves and instabilities that transition to turbulence. What is really remarkable about the PMC layer are at very high altitudes is that I would argue that although it is very remote, it is almost certainly the very best place to study those processes on the planet.

The physics certainly excites me, too. In fact, in , they were first reported in the literature. So our idea is that these clouds are actually produced by methane, or at least indirectly caused by methane increases, which have more than doubled over the past century or century and a half.

Methane is composed of carbon and four hydrogen atoms, and this decomposes in the upper atmosphere to form water vapor, which in turn collects on meteor dust particles. And so another aspect is that, in , there were fantastic red sunsets during that time because of the Krakatoa eruption that occurred two years before that.

So Gary, do you think these clouds can be used as a measure of climate change? The formation of ice is exquisitely sensitive to temperature changes, and also, to a lesser extent, water vapor.

So both of those quantities— temperature and water vapor— are changing in the upper atmosphere as a result of climate change. So, could it get to the point where we see them more, you know, visually for the general public? They get to be so ubiquitous? In fact, they have been seen over southern Colorado. Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.

The cookie is used to store the user consent for the cookies in the category "Analytics". The cookies is used to store the user consent for the cookies in the category "Necessary". The cookie is used to store the user consent for the cookies in the category "Other. The cookie is used to store the user consent for the cookies in the category "Performance".

It does not store any personal data. Functional Functional. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. Performance Performance. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.

Analytics Analytics. Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Advertisement Advertisement. Form smoke particles Ask an adult to light a match, blow it out and quickly drop it into the jar.

The smoke particles will provide a surface for the water to condense on. Cool it Immediately place an ice-filled metal tray or hard-plastic frozen ice pack on top of the jar.

Watch the cloud appear Observe the inside of the jar carefully. A misty cloud should appear near the top of the jar. Why does this happen? The warm water vapor mixes with air and smoke particles. It rises inside the jar and then cools when it comes near the tray of ice. As the water vapor cools, it condenses into very tiny droplets on the smoke particles. When enough condensation occurs, we see it as a cloud. If you have a hard time seeing the cloud, slightly lift the metal tray or ice pack from one side of the jar and look for wisps of cloud escaping the jar.

Make it disappear Remove the metal tray or ice pack. What happens? The cloud disappears. As the cold cloud warms up, the condensed water droplets evaporate once again and turn into water vapor.