Mad Crowd Sourcing Climate Science Experiments for Kids
Eli is looking for some climate science experiments that you can do with kids, K-12 roughly although also maybe first year of university. One quick one he came up with is have them record the temperature and altitude shown on the monitors on the seat in front of you when you get bored with the movie. Since many people fly with their kids (or dad or mom can be given an assignment), this might be an interesting way to teach the lapse rate.
If there was a high enough hill in the neighborhood, standing kids at different levels with calibrated thermometers and cell phones (assuming there was a nearby tower) might also be a way of doing this.
Also, such things as plotting ozone levels as a function of time of day an winds in urban areas might be something that could work.
These are but simple getting started ideas. Eli appeals to the madness of crowds of bunnies for other suggestions. Given the low budgets of most schools, yes, you cannot afford an IR spectrometer, but you might be able to handle a Spencer box or an IR thermometer level of expense and pretty much everyschool has a Weather Bug these days.
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Here's an idea:
Put an IR heat lamp over a bucket of water to demonstrate that IR from GHGs cannot heat the oceans.
Heat up a pot with a potato in water and a pot with a potato but no water, to show that water absorbs some of the heat. Note: this is hard on the pot without water.
Try Kitchen Chemistry by Lister and Blumenthan.
Put a wide pot of water containing a thermometer on a stove with its lid off and set the heat v. low so that after some time the water comes to an equilibrium temperature (say 50 oC) where heat loss from the surface balances heat from below.
Now put a lid (needs a hole for the thermometer) on the pan and get the kids to record the temperature as a function of time. Draw a graph.
This illustrates:
(i) the concept of dynamic equilibria
(ii) the change in an equilbrium temperature as a result of a forcing
(iii) the time-dependence of requilibrium to a new dynamic equilibrium under the influence of a forcing.
(iv) the concept of "heat in the pipeline" (for Dr. Lindzen-style kids, the realization that the earth doesn't reequilibrate instantaneously under the influence of a forcing)
Anon@3:53
Google skin effect.
SkS has d a piece here http://www.skepticalscience.com/Shorter_Wells.html in which they mention
Bengali ice-making, as described by Sir Robert Barker, 1775. I think this makes a great demo of radiative exchange between the surface and the upper atmosphere. May work a treat where you live.
I recall the physicist Brian Cox on a BBC program estimating the heat flux from the sun with a bucket of water and a thermometer in the desert.
The following site is rather disorganized. But the links lead to many ideas for those willing to burrow them out.
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http://www.climatechangeeducation.org/
The experiment to demonstrate the (essentially insulating) effect of IR heating of the very thin ocean surface layer(skin) has actually been done, but it's probably not something a kid could do in the kitchen on a Sunday afternoon.
As Einstein said, "Subtle is the Lord, but malicious He is not."
Real Climate had a good description of the skin effect experiment
Why greenhouse gases heat the ocean
"some have insisted that there is a paradox here – how can a forcing driven by longwave absorption and emission impact the ocean below since the infrared radiation does not penetrate more than a few micrometers into the ocean? Resolution of this conundrum is to be found in the recognition that the skin layer temperature gradient not only exists as a result of the ocean-atmosphere temperature difference, but also helps to control the ocean-atmosphere heat flux. (The ‘skin layer‘ is the very thin – up to 1 mm – layer at the top of ocean that is in direct contact with the atmosphere). Reducing the size of the temperature gradient through the skin layer reduces the flux. Thus, if the absorption of the infrared emission from atmospheric greenhouse gases reduces the gradient through the skin layer, the flow of heat from the ocean beneath will be reduced, leaving more of the heat introduced into the bulk of the upper oceanic layer by the absorption of sunlight to remain there to increase water temperature. Experimental evidence for this mechanism can be seen in at-sea measurements of the ocean skin and bulk temperatures."
~@:>
For the young ones seeing what happens to the outside of a glass filled with ice water gives an easy transition to how clouds form.
I think you would need a pretty big hill to check lapse rate but if the school is close to a NWS office you might get someone out to talk about upper air readings. You could then have students plot the information. A ton of information can be obtained from a skew-t.
A handyman could build a tank with a drum and crank. Fill the tank with water, turn the crank to simulate the earth spinning, drop in some food coloring and a long wave pattern may appear.
Take a few observations at night and compare the change on cloudy and clear nights. You will be able to see the GHE. Though different than the GHE of CO2.
"Real Climate had a good description of the skin effect experiment"
Heh, looking at the graph at Real Climate and extrapolating, doubled CO2 @ 4W/m2 "should" cause a mere 0.1C warming of the ocean skin, not 3C predicted by the IPCC. So much for CAGW.
What is causing the molecule thick cooling of the ocean surface? Evaporation. While the vapor pressure of the air is low enough water molecules will evaporate into the air without any need for external application of heat. Indeed this will even happen when it is cold – as in ‘lake effect snow’. The evaporation raises the water content of the air immediately above the water surface and, as moist air is lighter than dry air (the molecular weight of H2O is significantly less than either N2 or O2), the humid surface air will rise to be replaced by drier air). As the water molecules leave they take their energy – the latent heat of vaporization- with them. So the latent heat of vaporization comes from the water without radiative transfer. All externally applied IR will do is excite the molecules on the water surface that are close to escape energy and allow them to escape (i.e. become water vapor) earlier. Thus application of a low amount of IR at the right frequency can cool the surface layer of molecules as the surface molecules with the most energy /motion receive just enough extra energy to leave the surface and become vapor molecules, leaving behind those without sufficient energy to escape – the cooler molecules.
This means that any IR energy will have an unmeasurable effect on the temperature of the water (energy of the molecules below the surface) as the excited molecules leave taking more energy with them than has been applied.
Anon@2:12
Sigh. Once again, you are lost. The ocean warms because IR decreases the thermal gradient across the skin layer, thus decreasing heat loss from the bulk, not the surface. Crack a fricking book.
Once again, you are lost.
1) As explained above, downwelling IR at most causes evaporative cooling of the ocean skin, which increases heat loss by the bulk.
2) Even if believes the dicey paper on Real Climate, there is a mere decreased thermal gradient of 0.1C. Homework assignment for you Dilbert: explain how a decreased skin gradient of 0.1C causes 3C warming of the bulk.
Here's an idea:
Put an IR heat lamp over a bucket of water to demonstrate that IR from GHGs cannot heat the oceans.
17/5/12 3:53 PM
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Konrad at Tallbloke's did this experiment in his kitchen but came up negative on a heating effect.
Problems with his setup may be:
1. The ocean air 70% humidity reduces the supposed evaporative cooling effect. The experiment needs to incorporate that.
2. The water surface is well mixed by wave action. The experiment needs to incorporate water circulation.
3. The evaporated water containing the latent heat is in contact with a cold water surface so it will condense releasing that energy back into the water. The experiment needs to incorporate that possibly by recirculating the air.
These simple experiments are often not as simple as you might think, which is why climate skeptics find it easy to stop thinking when they get the answer they want.
I want to encourage them to do more experiments and maybe some humiliation from school kids might motivate them to do a better job.
Anon@5:16,
First, who is saying you get 3 degrees of warming? Over what time period?
And no, it isn't evaporative cooling. You have the physics wrong. Crack a frickin' book!
Dilbert, so sorry you're having trouble keeping up and are unable to do your homework or show your work
1) The IPCC claims the Earth, i.e. land + SSTs, will warm (midprojection) 3C per doubling of CO2 levels.
2) As stated in the Real Climate piece, the IPCC also claims a doubling of CO2 causes 4W/m2 forcing
3) Per the graph on Real Climate, a 4W/m2 change in forcing allegedly results in a mere 0.1C decrease in ocean skin temperature gradient.
4) How dense does one have to be to not understand that a 0.1C decrease in skin temperature gradient can at the very very most result in a 0.1C temperature increase of the bulk?
5) How dense does one have to be to not understand that 333 W/m2 of alleged IR backradiation concentrated within a few Angstroms of the ocean skin can lead to anything but evaporation?
6) Are you claiming that latent heat of evaporation does not cause cooling? Absurd
Anon@6:55, Boy, you really are stupid. The 3 degree per doubling is the amount the surface must warm on average to restore thermal equilibrium. It has nothing to do with the skin effect warming the oceans.
Dude, it's not about an absolute change in temperature. It's about a decreased thermal gradient leading to slower outflow of energy. Again, crack a frickin' book, moron!
Dilbert, you're dumber than a doornail...
1) According to you at 7:15PM, global warming has nothing to do with "the skin effect warming the oceans" while simultaneously claiming at 4:47PM above "The ocean warms because IR decreases the thermal gradient across the skin layer"
2) Address my questions #4-6 above. Show your work. Obviously you cannot, ergo you are the moron.
"Here's an idea:
Put an IR heat lamp over a bucket of water to demonstrate that IR from GHGs cannot heat the oceans."
Hmmm.
I've done fieldwork in large, shallow saltwater lakes, and in slow estuarine deltas. In the morning it can be darned cold from the surface to the bottom, but by mid afternoon on a summer's day the surface is easily five degrees celcius or more warmer.
If it's not infrared radiation that's responsible, I'm curious to know what is.
Anon@8:01,
As you are incapable of reading for content and unable or unwilling to crack a book, I see you are ineducable. And as you have made your stupidity manifest to all, you can do no further damage. Enjoy your ignorance, clownshoe.
By the way, just to do the math and show what a moron Anon is:
First, the skin depth is up to 1 mm thick, so a 1 square meter area weighs on the order of a kg. It takes 4184 J just to raise the temperature of a kg of water 1 degree C--that means that the skin depth would have to be stable for on the order of 1 second just for it to warm 1 degree!
To evaporate the water would require the skin layer to be stable for over 2 hours!!! Alternatively, the skin depth would have to be 128 angstroms thick. Since we are talking about 15 micron light, this is simply flat absurd!
What a fricking moron.
"If it's not infrared radiation that's responsible, I'm curious to know what is."
My, my, could it be UV [which penetrates water 300 m] from that huge fireball in the sky? BTW IR from GHGs is constant 24/7.
"To evaporate the water would require the skin layer to be stable for over 2 hours!!!"
Wow Dilbert - did you learn science from comic books? You CAGW believers are waaay dumber than I could possibly imagine. It is very well known that the skin layer is ~0.3C cooler due to evaporative surface cooling. Read this paper in nature instead of comics:
http://www.nature.com/nature/journal/v358/n6389/abs/358738a0.html
It is very well known that the skin layer is ~0.3C cooler due to evaporative surface cooling. Read this paper in nature instead of comics:
Eh, no. Ray is right, the value of 0.3C is the gradient across the skin. Not the temperature itself. And if you had actually read the article you link to, you would know that it has nothing to do with evaporative cooling -- you just made that up.
I disagree with Ray in that your problem isn't solvable by cracking a book. You need to learn to read first.
The attempts by some to connect the skin temperature issues with the amount of warming caused by doubling CO2 are fundamentally ill-conceived. To some extent the skin layer in the ocean may affect the rate of air-sea heat exchange, but this is not what primarily determines the surface temperature. That's primarily determined by the top-of-atmosphere energy balance. For those who have learned to read, the issue is fully discussed in Chapter 6 of Principles of Planetary Climate (see the section on the Surface Budget Fallacy).
One experiment that has crossed my mind is to measure sky temperature with an IR thermometer as a function of elevation and azimuth and to record cloud cover at the same time. Then correlate with absolute humidity via a temperature and relative humidity measurement.
This could all be done with arduino micro controllers and sensors and some decent signal processing.
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