 I think we're at two o'clock and as soon as Mark is all set to go he'll give us a thumbs up and we'll get started. Just a quick check. Can everyone hear me out there? If you can hear me and you're on camera give me a thumbs up. Awesome. Well let's go ahead and get started. My name is Mark Mueller. I work at the National Center for Atmospheric Research which is in Boulder Colorado and I'm gonna be coming to you from my home today probably into yours and we are going to work on an activity today together and I'm also going to be working with my colleague Tim and he's in his home so you'll be hearing a lot of talk between Mark and Tim and then a little later on we're also going to talk to a scientist that works with us at NCAR named Jeff. So we've already seen that we've got folks coming in from Boulder and Lewisville and that's so we're all in the same neighborhood. Thanks for saying hello everyone. We're excited to have you here today and we're going to get started with our activity so we're going to be exploring how air behaves when it changes temperature and then how that connects to the way clouds form. So first thing I want you to do is I want you to grab your bottle and I want you to notice your bottle should not have anything in it or in terms of nothing seems to pour out of it but is there anything in your bottle and you'll notice my bottle doesn't have a cap on it I can poke my finger in there so is there anything in there since nothing's pouring out of my bottle is our bottles just empty what do you think? Add your thoughts to chat. Yes, empty. We are sure that it's empty. Mine looks kind of empty too and you know but there's one thing in here that we don't think about often because it's invisible. It's air. There's air in my bottle. Did you see anything in there? Well no but it actually is full of air and air is made up of these tiny molecules. So these tiny molecules have gone inside my bottle and they're so small we can't see them but they take up space and they are inside of there. So what we're going to do today is we're going to find out how the air molecules behave inside of this bottle when we change their temperature from hot to cold. So first things first we've got our bottle it's empty or is it full of air right? We've got a little dish of soap ready to go I got a little rag if I make a mess. I've got my cold water which is icy cold so I'm going to put that down in my cold tank and I've got my hot water which I took out of a tea kettle and I'm going to pour that in on this side and why I do that I want you to know that I have a really big difference in temperature so I'm going to measure them for you. On one side here I have 39 degrees and on the other side I have 157 degrees so a big difference in temperature so get your hot and cold sides ready they may already be. I just got to pour all my hot water in here because I need all of it to warm up my bottle. There we go. All right so let's do this together you're going to do this with me. So grab your bottle and give it a soap hat which what I mean by that is stick it in the soap and pull it out of the soap and on top of the bottle you will see a little film of soap. That's now become the cap until I popped it. I accidentally touched it with my finger you might do this too you might have to go back to your soap dish often and start over by just dipping it into a little bit of soap until you see soap on top of your bottle. Okay so now there's a little bit of soap on top of my bottle and it's kind of making a very gentle small bubble. Do you got that? Okay so before the bubble breaks let's take the bottle and just on its bottom part put it in the hot side put it in the hot water ready go whoa what's going on my bubble popped yours might have popped too and it's going to be often that it pops maybe so I'm going to start over and try again you might need to try again as well go ahead and re-dip that bottle in the soap and put it back in the hot water it doesn't do anything. Well mine's doing something it's making a ginormous bubble and sometimes it gets so big it pops yeah so it says wow oh my goodness so see wow mine popped again so let's keep let's keep practicing that hot side for a couple more tries and so we can get those bubbles to rise and expand our bubbles are taking the air inside they're warming up the air molecules with the heat and they're expanding inside of the bubble so that's why the bubble's getting bigger. Then there was a question did you add air to that bottle? I did not add air by myself personally I let the air in this room press into the bottle because believe it or not we have a lot of air pressure pressing against our body right now it's around 13 and a half pounds per square inch at this level height on the earth so it's around 15 pounds per square inch at sea level so the air in this room naturally pushed into this bottle and I trapped it by adding the soap to the top and then that's why the air when warm pushes the soap in an expansive way. So just to be cleared I think it might not be perfectly clear what did make that bubble expand? Yeah what's making this bubble expand is not my hands it's not me squeezing the bottle because I'm not it's the hot heat that went in here that came from my tea kettle it warmed up the air inside of this bottle so much that the air molecules inside of there even though they're invisible started to spread out and expand and that's why I had a bubble until just a second ago it got so big it popped so I got to start over again. So what I'd like everybody to do out there is now to try to make a warm bubble but don't let it pop so I'm gonna let mine rise a little bit but I'm not gonna let it go quite so far this time and when it gets up about that high for about you know as big as your thumb go ahead and now take the bottle pull it out carefully and push it into the cold water. Where does the bubble go? It might have popped too so you might have to confirm what happened and start over give it some fresh soap give it some fresh expansion and then put it into the cold tub and see why in the world your bubble seems to go away. Where does your bubble go? Oh into the bottle it looks like we've discovered. Great so I've noticed that too let's keep track let's practice one more time let's go from hot expanding to cold and on this side we're going through contraction the molecules are actually huddling together getting tighter and closer together and contracting down inside of the bottle in fact I can point with my finger that my bubble has gone down one of them went down to this far there's a line inside of my bottle and I can see where the bubble stopped it went down all the way to where my finger is are you guys getting some of the same observations out there? Looks like we have a lot of experiments going on out there and a yes it looks like Boulder has a bubble going down down on the cold side yeah contracting on the cold side expanding on the hot side and if you're careful and don't let the bubble break you could actually go back and forth and make the bubble go up and down kind of like an elevator well from what I can see in the chat and what I've heard from Tim so far it sounds like it looks like you saw what I saw during this activity is that when I put my bottle into the hot water the bubble grew above the bottle and when I put my bottle into the cold water the bubble went down the mouth of the bottle I bet you're wondering what made the bubbles do this well remember there's tiny little air molecules inside of there and those tiny air molecules can actually change according to their temperature so the hot water heats up the air molecules they get warmer they spread out and expand that's why the bubble grows when the molecules expand inside your bottle they take up more space and this makes the bubble grow bigger on the hot side now when you put your bottle on the cold side the bubble moves down into the neck of the bottle and this is because cold water cooled the air inside the bottle and as the air gets colder those molecules huddled together and go down this is a word in science we call a contraction these colder water these colder air molecules need less space so that's why they can go down into a smaller part of the bottle they sink down into the bottle and that's why the bubble behaves that way so let's put our bottles down for a second you can continue playing with this at home everybody try this again but everybody put your bottle down for one second and I'd like to see if you can show me with your body with your arms and with your legs by standing up or standing up big or getting small we're gonna practice what just happened in our bottle so when the air got warmer show me with your body what happened to your bubble so when you did the hot side what did your bubble do did it expand and get bigger and bigger and bigger and bigger mine got really big maybe not that big but it got pretty big now let's pretend we got into the cold side and now we're in the cold water show me with your hands what happened to your bubble oh yeah it's contracting and taking up less space and going down the neck of your bottle I can't talk it's in my neck okay so you can see this is what we just acted out is exactly what the air molecules do inside this bottle it's the same air that's going in my mouth into my lungs and keeping me alive but it can change the way weather works too so now I'd like to introduce you to a scientist he's gonna talk about this activity and connect it to weather his name is Jeff hi there everybody I'm going to explain to you kind of how this same idea works in the real world now well while we were looking at a bottle filled with soap and hot and cold water that's really what's going on outside in our on our atmosphere today so what it's very similar to the the Sun coming in and heating up the surface of the earth and as the Sun comes up and gets the middle of the day and sends its radiation down to the earth it warms the earth up very nicely and that allows water in this lake and the hot air on the planet to rise on up so this red arrow is is the warm air rising just like the air rose in the bottle that you had earlier and so as this warm air starts to expand and and rise on up into the atmosphere it gets higher up in the atmosphere where it's colder and it turns into a cloud now as more warm air with with warmth and moisture keeps going up and cooling down and creating water droplets that make this cloud eventually there's so much water in this cloud that it can't hold it up anymore and so now we have all this water droplets up in these clouds that get so heavy that they're going to come down they're going to come down as either rain or snow or hail and so then that water comes back down to the surface of the earth and that's kind of what we call our water cycle and so this process that we're looking at it of air being colder and contracting and being warmer and expanding is really responsible for this part of getting the water from the ground up into the clouds and back down again and it's also why we have mountain and valley winds and the same reason why we have winds along the coasts ocean sea breezes it's all based on the same concept that as warm as the air warms it expands and rises up into the atmosphere and that creates all these clouds and gives us our sea breezes and so it's really a very basic concept of how the atmosphere works and sometimes we have these cool lightnings lightning bolts out of these thunderstorms as well that's that's one of my favorite things about weather is seeing the severe weather and the tornadoes and lightning bolts like this it's all very exciting these are probably my favorite types of clouds I'd be happy to ask answer any questions that you might be able to ask of me today and doesn't have to be about this topic it could be about anything about whether thanks for helping us understand how this whole works in the atmosphere and like Jeff said he's a meteorologist and he's ready to take your questions about what you've done or you can even ask him a little bit about his own work what he does as a scientist and Jeff we did have a question about water in the freezer expanding because it's cold and air expanding is are they the same or is that does Eric water expand in their freezer for is it different is it the same as air do water behave the same process and water is kind of magical in that way most substances contract when they're cold water is one of the few things that expands when it freezes and also water is very magical in a number of ways it also is not it's densest when it's frozen so that's why ice floats on the top of liquid water which is unusual compared to all the other materials we have on earth everything else when it gets frozen sinks to the bottom but if water behave that way we wouldn't have any fish because the lakes will all freeze from the bottom up so we're thankful the fish are very thankful that water is kind of the special substance that kind of behaves differently than all the other substances on earth and so water does expand when it gets cold but it's one of the few if not the only substance that does that on this planet and we did thank you we do have another question about forecasters how do weather forecasters use information to predict weather what's that look like when they they take measurements and use it to get to predict the weather that's a great question thanks for asking that now in relationship to what we were doing today when we see areas of the country that we know are gonna get a lot of sunshine and kind of heat up the surface we can forecast they're probably gonna be seeing some sort of cloud development over that area because that warm air is gonna want to rise and then cool down and make clouds and so that is something that we look at in our forecasts there are a lot of other variables that we look at doing our forecasting as well like how close are we to water and moisture sources because water is a very important part about weather there really isn't any weather without water so that's also very important but to expand the principle that we saw today when we know where there's areas of a lot of sunshine we can expect a lot of air parcels to warm and expand and rise and create clouds and so that is definitely a part of our forecasting process it looks like we're still having some fun out there and doing some exploring yeah my fellow science enthusiasts out there yay can you tell us something that you really enjoy about your job sure I love working at the National Center for Atmospheric Research my fieldwork was on the Greenland ice sheet and I was able to install automated weather stations all along the Greenland ice sheet and that's still bringing back data today so we can see how the ice sheets are changing another part that I really enjoy about my job is that we deliver real-time data to universities and research institutions all across the planet and then 3D visualization tools so that people can look at the weather in real-time and make better forecasts and do better science and so it's really great to be able to help science serve society and and reach out to the community and share our science to everybody wow that's really wonderful I'm glad that you offer this for what researchers all over the world is that yeah yeah all across the planet it's not just the United States and we serve the entire country the entire globe yeah well guess what we have a question about the Greenland ice sheet what is an ice sheet and can you walk on top of that wow those are really fun questions and so the ice sheet is a sheet of ice and it's been there for hundreds of thousands of years now when I was putting towers on the ice sheet I was walking on ice that was over two miles thick over 10,000 feet thick and so yeah it's been there for a long time it's gonna be there for a long time as well but it is starting to change it is starting to melt and so that's kind of a an interesting place where we're looking at the changes of our climate because the ice at the poles is changing rather dramatically but when we were on the ice sheet it was like being on another planet there weren't any animals at all because there's no food for the animals we didn't even see birds and so there was literally no animals or plants on top of the Greenland ice sheet we're about two two and a half miles above the planet just separated by ice and there's a it's like a landscape you can't imagine it's all you can see is white and in the sky and so it's it's a very interesting place to be but it's a very important place for us right now to study climate and climate change and and when you say climate or weather what's a good way to remember the difference between climate and weather I love this phrase the saying they often use and that is climate is what you expect and weather is what you get so climate is kind of the average weather that you get over that time period for about 30 years is how we average a climate time and so that's kind of over the time over the past 30 years we would expect April 8th like today to have a certain temperature and a certain amount of moisture and so that's kind of the average over time but we can get dramatically different types of weather on that day even though the climate indicates that we should be either warm or cold and so climate is the average expected temperature or precipitation rain that you would get over time whereas weather is just what you get and it can be very variable over time and so climate is what you expect and weather is what you get well you have to know a lot about science it looks like we have another question does it always get windy before it's snow someone observed that it's windier outside right now hmm yeah and oftentimes it does because when we get snow coming in it kind of indicates a change of the weather and so that's one piece of air that's on top of us leaving and another piece of air that might be colder and snowy are coming into us and so very often before snowstorms come we do get some wind and that's what we call a front a warm or cold front and those are often associated with wind I do think we're going to see some snow Sunday maybe as much as six inches of snow wow we'll see a change in the weather so yeah look forward to some more wind on Saturday we call these transition days when you go from warm and sunny and then some cold and snow is coming in there's gonna be like one day between those two events and those are often very windy days and we call those transition days between the warm and the cold weather really good question all right well I think we can go ahead and turn it back to Mark now to finish us up for this session thanks to thank you Jeff well Anna and Lisa thank you for joining us today we hope you enjoyed our activity if you'd like to learn more about weather the atmosphere the sun or earth system science you can visit our websites they're free and open and they have a ton of resources for you to learn at home Tim's going to put up in the chat those links so that you can go out to them and find more to do once we're offline we also have that on our Facebook page as well if you'd like to follow us there that'll give you additional virtual programming days and times this is our website here and you can see that it's got elementary middle how to be a scientist and even videos on all the topics that I just suggested about the earth so if you use that URL in your chat or that link it should take you to this page and from there you can literally go to many many more places to learn we want to thank you for your time and let's make sure we have no last second questions I think we're doing good awesome oh and someone doesn't want to know if we've recorded if there's a recording of this session guess what this session was recorded today so we don't know where we'll be able to make this available but please check back with at our website for the opportunity to see it again or you can just join us it maybe you can join us again for our next session again looking on the website to find out when we'll be doing this again I'm gonna I'm jumping in real quick this is Tiffany and I'm entering my email address so for particularly for the person who didn't or who wasn't set up you can email me and I'll get the video to you before we we do have to figure out how we're gonna post it or where we're gonna post it but I'm happy to connect with you over email and we can figure it out there you go great well again thanks everyone if you have all the information you need have a great day and we hope to see you again soon bye bye now we cover everyone did I'm gonna stop the recording