Selecting Questions From the DQB
Answering Questions as Groups
Sharing Out Questions in a Scientists Circle
With so much that we figured out about storm formation, we worked in groups to update our models to explain how it hails sometimes and not others! We also worked to answer questions on our Driving Question Board! Curious about how we do this? Check out the three videos below!
We've got so much to celebrate! Way to go 8th grade! I wonder how we'll extend all our "figuring-out" into our next unit on Climate!
Figuring out how water got into the air alongside the effects of when it cooled down left us wondering how something with weight could stay suspended in the air and not fall. So we turned to figuring out how differences between the updraft forces and gravity could affect what happens to droplets!
We feel that we're in a really good place understanding how storms, including those that produce hail are formed. Next steps: Update our models to include everything we've figured out and summarized in our Gotta-Have-It Checklists!
Now that we had an understanding of how water could end up in the air through evaporation, we were seeing the effects of what happens when you cool it down. Not only did water droplets begin to appear in a closed system, but the droplets got bigger and bigger as they were attracted to each other!
We're seeing changes but can't quite see them as they're so small. We turned to some magnetic marbles to really see what happens with water molecules are they cool down and warm up!
Both these investigations have allowed us to predict what we'd see both high up in the atmosphere when there's high humidity and low towards the ground.
So if there's humidity in the air, and it's cooling off and condensing to make clouds on CCNs, then why don't droplets fall all the time? Like why do some clouds grow taller and others stay suspended in the air?
So if we know that there needs to be high humidity when hail storms happen, how does water get into the air in the first place? We know that air is a mixture of many gases, including water vapor, so we agreed to figure out how the air gets more water vapor, or humidity in it!
We pulled out some humidity probes, and measured the humidity inside and outside our classroom, and yes, Mrs. Brinza brought in some humidifiers as CO air is typically very dry! We also invested in seeing how different environments around the Earth impact humidity levels, as water in the ground seems to play a huge role in ending up in the air above it.
We saw huge differences in humidity readings across various surfaces, and felt a need to show how the air could become so humid. We worked towards how the air can get water in it!
We're trying desperately to put ideas together here.
1. We know how the ground cover warms up the air via conduction.
2. We know that energy transfers between particles in the ground (earth materials and water) to get water to evaporate and make the air more humid.
3. We know that different ground covers absorb different amounts of sunlight, changing the rate of evaporation, and as a result, the amount of humidity in the air.
All this is getting us thinking...what should we investigate next knowing that the higher up you go, the colder it gets. So if air has a lot of humidity in it, how does this impact what happens in terms of hail formation? Check out some 8th graders' ideas..
Maybe investigate the energy transfer higher up? See how clouds form (b/c don't they form because of humidity in the air)? Good stuff here!
We agreed upon what air does as we saw what a heated balloon did in our classroom. As the heat affected the density of the air inside the balloon, the balloon/air rose, and as it transferred energy to the air around it, it became less dense and sank. This pattern repeats itself and is dependent upon the amount of energy that's absorbed by the ground cover.
We feel we've nailed down what's happening with the air. But the incoming clouds before a hail storm got us thinking about those specific clouds. We did some noticing with some images and a video Mrs. Brinza found, and annotated what's going on with the clouds as they form!
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We absolutely see the up-out-down movement of hailstorm clouds. And we know that it's warmer on days when it hails. This totally makes sense because if hailstorm clouds are as high as our research tells us, they need a lot of energy to get up as high as they do! But air isn't the only thing we need to consider. There's also high humidity when hail happens. Next steps: figuring out more about humidity!
Itf air heats up differently above different surfaces, how does this affect how air behaves? We worked through an opportunity to capture air in a bottle, and submerse it in water of different temperatures to see how the air behaved--the soap on top of the bubble was really insightful!
Really pinpointing where the balloon had more energy in the system vs. less, we officially defined density--how if the mass stayed the same, but if the volume of the molecules got bigger, the density would have to have become less. This is when we saw the balloon rise.
But if the mass stayed the same and the molecules took up less volume, then the density would have increased, and the balloon would have sunk. We also nailed down where the energy was transferring from and where it was going!
So how does this relate to our hail storm phenomenon? We reminded ourselves that the air is warm when hail happens, and yet there's a temperature change before and after the hail arrives. We're curious how if this rising and falling air causes wind (which we also saw) and how this relates to cloud movement (since we saw those, too)! We also know that hail is frozen water, and the humidity was high before the hail storm.
Next steps: Clouds, humidity and wind!
After sharing all our our groups' data we saw some interesting patterns. Areas that reflected less light were warmer than areas that reflected more. With some thoughtful conversation, we concluded that if an area was reflecting a lot of light, this meant it would be absorbing very little. This also meant the opposite...that if an area reflected small amounts of light, more light would have to be absorbed. And since air touches the ground, the ground could transfer energy to the air above it, warming it up.
We worked towards consensus on this idea, and here's our consensus model (a reading on conduction helped)!
All these cities' data gave us insight into the present conditions when hail forms. But what's stumping us is how it could be so warm (like warmer than the freezing point of water) and frozen water falls from the sky. So with some modeling, it's obvious that it's colder up in the air...but we wanted data to prove this.
We agreed with the following claim students were making: The higher up in the atmosphere, the colder it gets. But we were also wondering how it could be colder up in the air as you're getting closer to the sun. We are recognizing lots of things as we consider this: the air gets "thinner" up the higher you go (whatever that means) and the closer you get to the center of the earth, the denser the particles of substances are (i.e. land is denser than water, as water sits on top of it). We're also considering how sunlight plays a role in heating things up and how energy transfers between substances closer and farther apart.
We ventured outside to collect both temperature and light data, focusing on various surfaces and the air right above them. Could we collect data on the air right near the ground and then above it?
After comparing various groups' data, we are seeing the following patterns for most groups (assuming there was some error on our end with our thermometers):
1. The air is colder the higher up you go.
2. The air is warmer closer to the ground, no matter what surface we tested.
3. Darker things like asphalt reflect less light that brighter things like snow.
This is getting us thinking...
If darker things reflect less light, this must mean they absorb more light than lighter things. As a result, they have more energy in them, which means they can transfer this energy to the air above them. So does this mean that different surfaces can affect the air temperature above them? So many new things to consider, especially as we are seeing warm temperatures present when hail happens!
Hail occurs when:
We also saw that hail storms seem to be relatively small in size and are similarly shaped (usually like a line). We left class thinking how all these factors that cause hail are actually working together. But our biggest concern is if the air is warm, how it is that hail forms and stays solid as it falls? Seems kinda crazy how that happens repeatedly!
Many students are suggesting it's because the air up higher is colder, and the wind plays a role. Next steps: figuring out about the air wayyyyyyyyyyyyyyyyyy up high!
After looking at our initial models, our class consensus models, and our related phenomena lists, we sat in another scientist's circle to develop our DQB! SO many great questions we have to figure out!
After hearing our classmates' questions, we came up with investigation ideas or data we needed to be able to answer our questions. It looks like students really need to get their hands on data--real data!