Weather Stations: Winds
Adapted from Toasty Wind, JetStream — Online School for Weather, National Weather Service.
Children use a toaster to generate wind and compare the appliance's heat source to Jupiter's own hot interior. They discover that convection drives wind on Jupiter and on Earth.
What's the Point?
- Jupiter's weather is generated by a strong convection of gases from Jupiter's hot interior to cold upper atmosphere. Only part of its heat is from the Sun's light; the majority comes from deep within.
- The Juno mission will help us better understand Jupiter's turbulent atmosphere by measuring temperatures at different depths.
The following materials are for this Weather Stations activity set.
Three sets are recommended for a station.
- Optional: Wide tape or cord cover
- 1 kite, constructed from
- 1 (12") dowel
- 1 (3.5x3.5") piece of aluminum foil (not "heavy duty")
- 1 paperclip
- Winds Seen from Space
For each child:
- His/her My Trip to Jupiter Journal or just the relevant "Weather Stations: Winds" page
- 1 pencil or pen
Facilitator's Note: Instead of the toaster, you may wish to use an electric candle lamp as your heat source. Have two lamps on hand. Use one to allow the children to predict whether the lamp creates wind or not (see the discussion in step 2 of the activity below). Bring out a second lamp, on which you have mounted a revolving lamp shade, to demonstrate how the movement of warmed air spins the shade (in place of step 3). Lamp and shade kits may be purchased from retailers such as Spin Shades Corp.
- Construct a "kite" by first partially stretching out the paperclip.
- Hook the looped end of the paperclip onto one end of the dowel; it will be a tight fit!
- Puncture the aluminum foil with the straightened end of the paper clip to suspend it. The “kite” should be able to move freely to catch “wind” flowing from different angles up from the toaster.
- Set out copies of Winds Seen from Space.
- Provide an appropriate space where at least one toaster can be safely plugged into the wall. It may be necessary to tape down the cord or install a cord cover to prevent tripping.
- Arrange for an adult or older child to facilitate this station. The toaster used in this activity poses a fire hazard and the appliance will get hot. In addition, the aluminum foil is conductive, but plastic alternatives may melt and paper alternatives pose a fire hazard. Modify this station to serve as a demonstration, if desired. Please use proper caution!
1. Assess what the children know about winds on Earth.
- Do you often feel wind? Does the speed and direction of the wind change from day to day?
- What creates the winds on Earth? The children may have a variety of ideas, including mechanical sources, like fans or moving in a car, and natural sources, like falling rain dragging air along. Allow the children to offer and confront possible erroneous ideas, such as that cold temperatures, the Moon, trees, or clouds cause wind.
2. Explain that the children will model the natural source for winds on Earth using a toaster. They will use aluminum foil "kites" to detect the wind. Turn the toaster on so that it has time to heat up.
- Can a toaster create wind? Accept all answers.
Have the children write their predictions in their journals.
3. Invite the children to hold the dowel and suspend the"kite" over (10-15 inches) the top of the toaster. Take care to keep the "kite" from falling into the toaster! Ask the children to note the results in their journals.
- What happened? The "kite" started fluttering.
- What made the "kite" move? Air, warmed by the toaster, rose and pushed against it.
Explain that wind is simply air molecules in motion. The glowing coils in the toaster produced infrared radiation, heating the toaster. The heated metal then warmed the air in the toaster, making the air less dense and causing it to rise — creating wind.
Facilitator's Note: Jupiter's clouds shroud a very turbulent place. The immense pressure of the planet's bulk crushed the interior as it formed (and possibly because Jupiter continues to contract) and the resulting heat is still leaking from the planet. Jupiter is far from the Sun, so this internal heat plays a major role in its weather. (Jupiter radiates twice as much infrared energy as it receives from the Sun!) Its core temperature may be about 43,000ºF (24,000ºC) — hotter than the surface of the Sun.
This heat source is not unlike the toaster in this activity. Atmospheric gases boil up from the warm bottom layers to the cooler upper layers; temperatures are –261°F (–163°C) at the top of the atmosphere. This convection of the atmosphere creates powerful winds.
Earth's highest surface wind speed ever officially recorded is 231 miles (372 kilometers) per hour, while the strongest winds on Jupiter reach 330 miles (530 kilometers) per hour.
4. Apply the small-scale toaster model to the much larger scales of the Earth and Jupiter. Discuss how is wind is formed on these planets.
- What is the heat source on the Earth? The Sun's light.
- How does the Sun cause wind? The Sun's light heats Earth's surface, and that heat is passed to air touching the ground. The warm air becomes less dense and rises. As cold air moves in to replace the rising air, we feel wind.
- What is the term for this flow of warm air rising and cold air sinking? Convection.
- Unlike our toaster, the planets are in motion. How are they moving and what does that motion do to the gases in their atmospheres? The planets are spinning. This spins the atmosphere as well.
- Jupiter spins once every 10 hours (compared to Earth's 24–hour day). What does this mean for its atmosphere? Jupiter's rapid rotation creates super–strong winds, called jet streams, which give the planet its banded appearance.
Explain that Jupiter is far from the Sun, and it does not receive nearly as much sunlight as Earth. Jupiter is so large, though, that it has heat leftover from its formation (and possibly as it continues to fall in on itself). Spacecraft instruments can detect a signal of this heat — infrared energy — and measure that Jupiter emits twice as much infrared energy as it receives from the Sun.
5. Ask the children to compare the winds seen on Jupiter and Earth on the Winds Seen from Space poster.
- How many jet streams does Jupiter have? Five.
- Does Earth have any jet streams? Yes, two.
- How are they different? Jupiter's winds are much faster and the bands flow in alternating directions.
Facilitator's Note: Jupiter spins on its axis once every 10 hours. The rapidly spinning planet generates five jet streams in each hemisphere that produce Jupiter's unique banded appearance. Earth has only about four dynamic jet streams, two — sometimes three — in each hemisphere, which all travel from west to east.
Summarize that convection creates stormy weather on both Jupiter and Earth. The Juno mission will measure the temperature of Jupiter's atmosphere at different depths to better understand the heat that drives the winds.
- What kind of instrument do you think Juno could carry to do this? Thermometer.
Remind the children that since the Juno spacecraft will not enter Jupiter's atmosphere, it will take Jupiter's temperature from orbit and "see" more deeply than any instrument has before. Scientists want to better understand the atmosphere's temperature at different levels, how it has such strong winds deep inside, and how the gases are whipped into the bands we see across Jupiter's exterior.
Allow the children time to note their conclusions in their journals.