I'm on a bike ride in my neighborhood right now and I'm seeing some pretty beautiful clouds.
These are cumulus clouds — when 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 sky — called
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
information — and 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 clouds — like those cumulus ones.
Cumulus means “heap” in Latin, and you can kind of see why — they 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 means “layer.” They cover the sky like a blanket.
They vary in color. So you can see some that are whiter but they can be grayish – they
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 shapes — combined with how high they are in the sky — create
the most common clouds. Like this cirrostratus clouds — which 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 sheet — like 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, too — they 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 example — look at this photo my friend
Jess took while canoeing.
These are definitely cumulus and cirrus clouds. We know that cumulus are associated with fair
weather – However, 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 cools — which 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 too — called 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 contrails — which just means “condensation trails.”
They’re made of water vapor from a plane’s exhaust, and mimic nature’s wispy cirrus
clouds — meaning 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 ground — it 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 watchers — like 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 below – or have them do it for you. Happy cloud hunting!