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IMPORTANT: IF YOU HAVE A HEART PACEMAKER OR ANY OTHER ELECTRONIC MEDICAL DEVICE YOU CANNOT DO THE VAN DE GRAAFF EXPERIMENT.
YOU CAN STILL DO THE REST OF THE SHOW.
Notes: L SCREEN refers to HOUSE LEFT SCREEN, etc.
“LOGO” means the DMNS Weather Central logo is on the Left and Right screens
Script / Media and NotesLOGO
Walk-in lights
Hi Everybody, my name is XXXXX
It’s not a real show, it is an imaginary show, so I’ll be asking you to use your imagination.
In this show, I hope that you’ll see how space technology is used for tracking and predicting the weather, and that you’ll learn some of the science that causes the weather.
This is a make believe TV show where people e-mail their questions to us. And to answer them, we’ll be following an imaginary summertime storm in Colorado. We’ll have field reporters to tell us what is happening outside and we’ll be doing experiments on the stage to explain the science.
You guys are the studio audience. When I say, “This is DMNS Weather Central,” you folks clap.
Are you ready?
Then, let’s go. / LOGO
Pre-show lights
Hi everybody, my name is XXXXXX and this is DMNS Weather Central. This is the show where we answer your questions about the weather. / L/R SCREENS: Opening theme and Title
Let’s start out by checking the Internet to see what questions come up.
Here’s one from JWiggins. He asks:
When I was in Colorado last June, I saw the worst thunderstorm and tornado of my life. Can you tell me where lightning and tornadoes come from?
To answer JWiggins’ question I’d like you to use your imagination.
Imagine that it’s summertime. It’s the afternoon. The weather is beginning to get cloudy.
We have field reporters all over the Denver Metro area to tell us what’s going on with our imaginary thunderstorm.
Right now, let’s check in with 9 News meteorologist, Marty Coniglio, to tell us what’s happening outside. / L/R SCREENS: Question from Internet
Hi this is 9News Meteorologist Marty Coniglio reporting for Weather Central.
I’m live right now in City Park near the Denver Museum of Nature and Science. It’s clear here right now, it’s a beautiful day. But I’m noticing some things; The wind blowing out of the east coming toward me and headed to the mountains, there is a lot of low level moisture in this wind, we can feel the humidity in the air, it’s a little bit sticky and as that’s forced up by the mountains we are seeing some clouds form.
As that air rises higher and higher into the colder parts of the atmosphere more of that moisture will condense into drops and form clouds and that releases a tremendous amount of energy. We could have some thunderstorms forming in the later part of the day. We’ll keep an eye on that back to you in the studio. / L/R SCREENS: Marty Coniglio – Outside of Museum FIELD REPORT
Marty mentioned that when the Sun heats up the ground, it causes warm, moist air to rise up. / L/R SCREENS:
Ground heats up
And when it gets cool enough, it forms a cloud. / L/R SCREENS:
Clouds form
How many of you have ever seen clouds forming over the mountains?
This is what you probably saw, and what Marty saw.
- The air hits the mountains and RISES UP.
- As it goes up, the air EXPANDS because there is less pressure up there.
- That causes the air to COOL.
Warm air hits a mountain.
- And a CLOUD FORMS.
Cloud forms over mountain
I have a CO2 cartridge here. Inside the gas is under a lot of pressure. (Go into audience to have a visitor feel the temperature of the CO2 cartridge.)
Is this CO2 cartridge really hot, really cold, or about medium? (Answer you should get is “medium.”) / L/R SCREENS: CO2 cartridge.
(As you walk back to the stage.)
I’m going to release the pressure on this canister and the CO2 will expand, just as air expands when it rises. Let’s see what happens to the temperature. / L/R SCREENS: CO2 cartridge showing expanding gas.
- Attach thermometer to cartridge, start graphing and measure temperature.
- Release pressure.
- Have audience watch temperature graph and you read out new temperature
- Again let the front row feel the cartridge and ask about temperature. (Very Cold)
- Conclusion: When a gas goes from a higher pressure to a lower pressure it expands and cools off.
L SCREEN: computer thermometer probe graph
We’ve just seen that when a gas expands quickly, it gets cold. The same thing happens outside.
- When the air rises up, it expands because there is less pressure up there.
- It gets cold.
- And a cloud forms.
OK, we know that air gets colder as you go up, but how much colder does it get? To find out, we sent museum science educator Jennifer Moss Logan out to the National Weather Service where they are about to launch a weather balloon.
Jennifer, what’s happening out there? / R SCREEN: CO2 cartridge showing expanding gas remains on screen.
L SCREEN:
Warm air hits a mountain. (same slide as before.)
This is Jennifer Moss Logan, science educator at the museum. I’m here at the National Weather Service out at Stapleton.
Here on the ground the temperature is 78 degrees but to find out what it is further up the National Weather Service sends up weather balloons. These balloons go up to 100,000 feet. As they rise up they measure temperature, pressure and other related information and radio it back to us.
Oh, there it goes. As you rise up through the air the temperature gets colder and colder in fact it gets so cold that water vapor condenses into water drops and those drops form clouds that’s called the dew point.
Back to you in the studio. / L/R SCREENS: Jennifer Moss Logan – Weather Balloon FIELD REPORT
As Jennifer was just saying, when the water in the air gets cold enough, it condenses into a cloud. Let me explain.
In this picture, the ORANGE dots are air molecules and the BLUE dots are water molecules.
The BLUE dots that are all by themselves are water VAPOR, individual water molecules. This room is filled with water vapor, but it’s invisible.
When the water gets cool enough, it condenses and clumps together. Those are water DROPLETS, and that’s what you see in clouds.
So, if we wanted to make a cloud in this room, all we would have to do is make it cold enough and the water vapor in the room would condense into a cloud.
Who would like to see me make a cloud in here?
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To do that, we’re going to use liquid nitrogen, 321º BELOW ZERO Fahrenheit. So I need to put on my safety equipment.
- Pour liquid nitrogen into pan
- Pour in water
- Fan it with pie tin
Even with the updrafts, if the water droplets get too big, they can fall as rain.
That’s how you make a cloud here in the studio. But, to get the BIG picture, we need to look from space. / L/R SCREENS: Water vapor and water droplets.
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YOU MUST WEAR LIQUID NITROGEN SAFETY GEAR
In 1974, the first satellite was sent into geosynchronous orbit 23,000 miles above the equator to study Earth’s weather. That means that it always stays above the same place on Earth.
This satellite is a GOES satellite and is up there right now. It has cameras pointed down at the Earth. It sends those pictures to Silver Spring, Maryland where they are relayed to the National Center for Atmospheric Research in Boulder, which sends them to us.
This is something that no one was able to see until the space age, and now we use it every day. If you were to go 23,000 miles into space and look down, this is what you would see.
OK, let’s find out what is happening with our imaginary thunderstorm. Let’s zoom in on Colorado. / CENTER SCREEN DOWN
C SCREEN: Full Earth Visible Satellite image
L SCREEN: GOES satellite
R SCREEN: NCAR
This is a satellite loop. Denver is HERE on the map. (Yellow dot.)
Whoa. This is really interesting.
You can see that even though some of the clouds are coming in from the southwest, large storm clouds are FORMING right here over Denver.
And look how FAST they are forming. That means this could be a really big storm.
Can you see this dark shadow? That means the clouds must be REALLY TALL to be casting a shadow several miles long on the Earth.
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There is an even better way to see how tall the clouds are. Remember how Jennifer said that it gets colder the higher you go in the atmosphere? Well that means that the TALLER the clouds are, the COLDER their tops will be.
This GOES satellite has infrared cameras on it, which can read the clouds’ temperature. Let’s look. / CENTER SCREEN VIDEO: Visible cloud cover loop.
L SCREEN: GOES satellite
R SCREEN: NCAR
The BLUE areas are COLDER, and COLDER means HIGHER. So we can see exactly where the really tall clouds are, the ones that might form the biggest thunderstorms.
You see that dark blue? That is the storm cloud. Look how tall it is and how fast it’s forming.
Well, this is what it looks like from space. But we want to know what’s happening outside. So we sent David Grinspoon, atmospheric scientist here at the Museum out to give us a report.
Dave, can you tell us what’s happening out there? / CENTER SCREEN VIDEO: IR loop.
L SCREEN: GOES satellite
R SCREEN: NCAR
Hello this is David Grinspoon Atmospheric Scientist at the Museum reporting for Weather Central.
I’m out here where a very large storm is developing very quickly. I’m standing under a huge rain cloud and as you can see there are large shafts of rain behind me. There are large updrafts and large downdrafts within the cloud. Those updrafts and downdrafts separate the charges in the cloud, the electrical charges, and that makes lightning.
Each one of these lightning strikes carries over 100 million volts of electricity and can heat the air to 50,000 degrees Fahrenheit. You know, that means it’s really not so safe out here so I think I better get inside.
Now back to you in the studio. / L/R SCREENS: David Grinspoon – Lightning FIELD REPORT
CENTER SCREEN UP
OK, Dave, you better get inside where it’s safe.
It’s not safe to be outside when there’s lightning. We wanted to find out why, so we came up with a way to make SAFE LIGHTNING here in the studio. Would you like to see it?
We’re going to be making lightning with this Van de Graaff generator. Not only will you see the lightning right here, but it sends out electromagnetic pulses in every direction.
Because of that, IF YOU HAVE A HEART PACEMAKER OR OTHER ELECTRONIC MEDICAL DEVICE, YOU NEED TO STAND BEHIND THOSE FIRST TWO COLUMNS.
In the meantime, let’s see what causes lightning. / L/R SCREENS: Van de Graaff generator
How many of you have ever gotten a shock by walking on a rug? That’s static electricity.
How many of you have ever rubbed a balloon on your sleeve and stuck it to a wall? That’s also static electricity.
Well clouds make static electricity, too.
Inside the cloud, water, hail, and snow are all rubbing past each other building up static electricity.
Usually the positive charges go to the top of the cloud and the negative to the bottom. / L/R SCREENS: Cloud with Charge Separation
The negative charge in the cloud starts traveling down towards the ground. This is called the STEPPED LEADER.
Since opposite charges attract, the negative charge at the bottom of the cloud attracts a positive charge in the ground directly below it. That’s called the POSITIVE SHADOW. / L/R SCREENS: Lightning Sequence – Stepped Leader and Positive Shadow
As the stepped leader gets closer to the ground, the positive charge is attracted towards it. Since it is easier for electricity to travel through the tree than through the air, the positive charge moves up the tree. / L/R SCREENS: Lightning Sequence – Positive Charges going up tree
As the stepped leader gets very close to the ground the positive charge begins to climb up to meet it. This is called an UPWARD STREAMER.
They are forming a path of low resistance through the atmosphere. / L/R SCREENS: Lightning Sequence – Stepped Leader and Upward Streamer almost touching
When the stepped leader meets with the upward streamer, the positive charges rush up to neutralize the charge in the clouds. That’s the LIGHTNING STRIKE that you see.
The whole process takes less than 1/100 of a second.
What you don’t see is the Electromagnetic Pulse that goes out in all directions. That’s that I want to show you with the Van de Graaff generator. / L/R SCREENS: Lightning Sequence – Lightning Strike
- When I turn on the motor, the rubber band inside here will start moving.
- That will build up negative charges on the dome, just like in the clouds.
- This wand will become positively charged, just like the ground.
- And you’ll see the lightning here.
Can you see the lightning?
Now multiply it by 1000. That’s how strong real lightning is – 100 million volts! You can see why even at a distance, lightning can be a dangerous thing. / L/R SCREENS: Van de Graaff Generator
LIGHTS GET DARK
So, remember, even if you see lightning at a distance you should GET INSIDE A HOUSE.
If you cannot get inside a house, then get into a CAR.
What you DON’T want to do is to stay outside.
So, shout it out. Where should you go if you see lightning?
OK. We’re nice and dry inside the studio. But, Marty Coniglio is still outside checking on the storm. Let’s find out what’s happening out there.
Marty, can you hear me? / L/R SCREENS: Lightning Sequence – Positive charges in kid
Hey, it’s Marty Coniglio again.
We’re getting kind of worried here. The hail just started and some of these hail stones are as big as golf balls. Now these large hailstones mean this storm has huge updrafts of wind. If they’re strong enough to hold these big hailstones aloft they could be strong enough to cause a tornado.
I’m going to get in the truck and get out of this but we’ll keep the camera rolling so you know what’s happening. / L/R SCREENS: Marty Coniglio – Hail Storm FIELD REPORT
Marty said that large hail means strong updrafts. Here’s why:
Remember I said that there were updrafts holding the clouds up. The updrafts hold the water droplets up until they are big enough to fall as rain.
Let’s zoom in. / L/R SCREENS: Cloud with updrafts and hail
If you have strong updrafts, they can push the droplets high in the clouds long enough so that ice can form around them. You get hail. The stronger the updrafts, the longer the droplets stay up, and the bigger the hailstones.
That’s why Marty said that large hailstones mean strong updrafts, which could cause tornadoes.
Here we have, from the Museum’s collection, a replica of one of the largest hailstones ever reported.
Imagine how strong an updraft must have been to hold something this heavy up in the clouds! When the updrafts are THAT strong, we could be in for severe weather. / L/R SCREENS: Cloud with updrafts and hail – close-up
We wanted to find out what happens when you get updrafts like these, so we came up with an experiment.
- Inside this box we have a hotplate, heating up the air.
- To get warm, moist air, let’s add some water. (Put pan and water into tornado box.) In a minute, it will begin to boil.
- When the warm air rises it goes out the top of the box. More air needs to rush in to take its place. We’ve cut slots here, here, here, and here to let the air come in.
- (Sometimes, because it is so dry, I may need to add a little more water. (Spray bottle (optional))).
Let me know when you can see what is in there.
Yes, it’s a tornado, and it forms because the air is rising out of the box and air rushes in from the four sides to fill . . . / LOGO
LIGHTS GET DARK
(((Alert Sound))) The National Weather Service has issued a Tornado Warning for parts of Adams And Denver Counties. (((Alert Sound))) We Repeat. The National Weather Service has issued a Tornado Warning for parts of Adams And Denver Counties.
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