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  • I'm on a bike ride in my neighborhood right now and I'm seeing some pretty beautiful clouds.

  • These are cumulus cloudswhen you're outside on a bright, sunny day, you might

  • see hundreds of them. Like all clouds, they're formed when water vapor in our atmosphere

  • sticks to tiny particles of dust and salt and pollution floating around in the skycalled

  • aerosols. When the vapor hits an aerosol, it transforms into water droplets or ice crystals.

  • And when enough of those come together, they form clouds. Every cloud is packed with

  • informationand knowing a bit about them can help you tell the difference

  • between a cloud that'll disappear in a few minutes...and one that could ruin your picnic.

  • To really know what's going on in a cloud, you have to go right inside it.

  • That's what atmospheric scientists do!

  • I use satellite data, aircraft data, and even sometimes weather balloon data to understand

  • these processes associated with clouds and precipitations.

  • That's Dr. Mayra Oyola, she's an atmospheric scientist who works at NASA's jet propulsion

  • lab. She's also very good at identifying cloudslike those cumulus ones.

  • Cumulus meansheapin Latin, and you can kind of see whythey look like big heaps of

  • cotton. I saw a bunch when I was on a bike ride in August.

  • These clouds are normally present when we have fair weather or good weather. So it's

  • a good day to go outside and play. Cumulus are one of the 10 most common cloud types,

  • which scientists started defining all the way back in 1802: There's also Stratus,

  • which meanslayer.” They cover the sky like a blanket.

  • They vary in color. So you can see some that are whiter but they can be grayishthey

  • are normally associated with what we call fair weather. Our friend Anna in Michigan

  • saw some of those: “The weather today is nice and warm.” Cirrus, which means

  • curl, look like wisps of hair high in the sky. My coworker Agnes found these above Lake

  • Michigan in Chicago.

  • Cirrus clouds, because they're so high, they're very cold. They're mostly ice, very tiny particles

  • of ice, and they're short-lived. And there's Nimbus, which means rain.

  • They're normally seen during a thunderstorm, along thunder and lightning.

  • These four basic cloud shapescombined with how high they are in the skycreate

  • the most common clouds. Like this cirrostratus cloudswhich exist

  • above 7,000 meters.

  • They're kind of like thin sheets that spread across the sky. These clouds are interesting

  • because they tend to be useful to do weather forecasting in the sense that they can tell

  • you if there's precipitation or snow storm coming within 12 to 24 hours.

  • Altostratus and altocumulus clouds hover a bit lower, between 2,000 and 7,000 meters.

  • They often form a sheetlike these fluffy altocumulus ones Vox producer Laura saw in

  • Maine. If you see them in the morning, this is a tip for weather forecasting. What it

  • means is that you need to be prepared because they're normally produce ahead of thunderstorms.

  • Altostratus are less puffy, and more like one big blanket.

  • They normally thicken into being more type of rain bearing clouds like nimbostratus.

  • If you see a low, dark gray blanket of clouds, you're probably looking at nimbostratus

  • and it's probably already raining, like it was in my backyard the other day.

  • Really coming down out here.

  • Rain often comes from cumulonimbus clouds, toothey tower from close to the ground

  • to really high in the sky.

  • They're not gonna be your classical white puffy clouds. They're probably gonna be darker

  • and grayish. So they're very distinct and very easy to identify.

  • When you look at this chart, it seems pretty simple to tell the difference between these clouds.

  • But in reality, it can get a little tricky. For examplelook at this photo my friend

  • Jess took while canoeing.

  • These are definitely cumulus and cirrus clouds. We know that cumulus are associated with fair

  • weatherHowever, in this particular case, I can probably tell that there was a storm

  • before the picture was taken.

  • For the most part, storms tend to expand all over the atmosphere. So you have impacts of

  • the storm really high up in cirrus clouds, tend to be really high up in the atmosphere.

  • During sunrise or sunset, it's pretty common to see a colorful mix of clouds in the sky.

  • It's very specific in the sunset because you obviously have a very sharp change in temperature

  • going on at the time.

  • Those 10 clouds we just talked about make up nearly all the clouds in the world.

  • But what about the ones that don't fit on this chart?

  • Like here, on top of Mount Fuji in Japan.

  • Mountain ranges and other high obstructions disrupt the normal flow of air.

  • As air moves over the mountains, sinking air warms and rising air coolswhich creates

  • these lenticular clouds. They look like fluffy UFOs.

  • Extreme weather can bring unusual clouds all over the world. Imagine you're sitting outside

  • and you start to see these bumpy, baggy clouds roll in: They're called mammatus clouds

  • and they usually come along with thunder, lightning, and rain.

  • They're mostly composed of ice. And so basically the ice falls, and you have this pouches extending

  • sometimes hundreds of miles in any direction

  • Ice crystals help create these weird clouds toocalled Fallstreak holes. Scientists

  • think they're created when ice crystals in a cloud form really quickly, and either

  • evaporate or sink to the ground.

  • So they leave this big hole around the center of the cloud.

  • Some clouds don't even come from nature:

  • These are called contrailswhich just meanscondensation trails.”

  • They're made of water vapor from a plane's exhaust, and mimic nature's wispy cirrus

  • cloudsmeaning they are high up, and disappear really quickly.

  • Because clouds are above us we tend not to give them a second thought, but they are super

  • important because they not only regulate temperature on the planet, but they're also the primary

  • drivers of rain and precipitation, which we need to live.

  • For us cloud observers on the groundit takes practice to identify clouds.

  • A good tip is to have a cloud chart. With a cloud chart it's very easy to at least distinguish

  • the clouds are at the bottom. And the clouds that you normally tend to see at the top of

  • the clouds are on the middle layers are probably the most tricky ones

  • There are lots of communities out there for cloud watcherslike the Cloud Appreciation

  • Society, which accepts submissions of clouds from all over the world and adds them to photo

  • galleries online. If you're ever stumped by a cloud, it might help to

  • look at it from above: The National Oceanic and Atmospheric Administration has a near-real-time

  • satellite view of clouds that you can access online. When you combine all these tools together, you can start making

  • predictions about your day, just based on the clouds above you.

  • I think those clouds mean that it will be nice for the next couple of hours. Those big,

  • white, wispy clouds up there mean that it is going to be nice.

  • The cloud chart we made for this video was super helpful when I was first learning to identify

  • clouds, especially when it came to telling the difference between the basic ones, like

  • cirrus, stratus, and cumulus. To download and print out your own cloud chart, like the

  • one we showed in this video, get permission from your guardian or parent to go to the

  • link belowor have them do it for you. Happy cloud hunting!

I'm on a bike ride in my neighborhood right now and I'm seeing some pretty beautiful clouds.

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How to be a cloud detective

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    林宜悉 posted on 2020/09/04
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