Convention Currents Lab
In this lab, we learned about the principle of convection, and how it helps atmospheric circulation and ocean currents.
Materials: 1 clear plastic box, 1 pipette and 10 styrofoam cups.
Materials: 1 clear plastic box, 1 pipette and 10 styrofoam cups.
Pre-Lab Questions
1. Match the term below with its definition.
Conduction- the transfer of heat by touching
Convection- the transfer of heat in a fluid (air or water) that rises due to the density differences
Radiation- the transfer of heat by infrared waves
2. If one beaker contains 100 ml of cold water, and another contains 100 ml of hot water, which beaker contains more molecules? Explain.
The beaker of cold water has more molecules because cold water has more density.
3. Which water, hot or cold, would have the higher mass? Which would have the higher density? (Hint: Remember, density = mass per unit volume; d = g/cm3)
The cold water would have the highest mass.
4. As you open a refrigerator door, what happens to the air inside?
C- The cold air escapes from the bottom, sinking toward the floor.
5. As you lift the lid from a pot of soup, do the gases that escape rise from the pot, or sink around its base? Why?
The gases rise from the pot.
6. If you swim to the bottom of a pool and place a cork on the bottom, will the cork stay in place? Why or why not? Explain.
The cork will stay depending on the density of the pool.
7. Both air and water are fluids. What will happen to an area within a fluid that becomes warmer than the surrounding fluid?
It will rise, and we will have an area of low density.
8. Atmospheric pressure is the pressure exerted on earth by the force of gravity pulling the air towards the earth's surface. Where air is rising from the surface, will the atmospheric pressure be increased or decreased?
The atmospheric pressure will be decreased.
Conduction- the transfer of heat by touching
Convection- the transfer of heat in a fluid (air or water) that rises due to the density differences
Radiation- the transfer of heat by infrared waves
2. If one beaker contains 100 ml of cold water, and another contains 100 ml of hot water, which beaker contains more molecules? Explain.
The beaker of cold water has more molecules because cold water has more density.
3. Which water, hot or cold, would have the higher mass? Which would have the higher density? (Hint: Remember, density = mass per unit volume; d = g/cm3)
The cold water would have the highest mass.
4. As you open a refrigerator door, what happens to the air inside?
C- The cold air escapes from the bottom, sinking toward the floor.
5. As you lift the lid from a pot of soup, do the gases that escape rise from the pot, or sink around its base? Why?
The gases rise from the pot.
6. If you swim to the bottom of a pool and place a cork on the bottom, will the cork stay in place? Why or why not? Explain.
The cork will stay depending on the density of the pool.
7. Both air and water are fluids. What will happen to an area within a fluid that becomes warmer than the surrounding fluid?
It will rise, and we will have an area of low density.
8. Atmospheric pressure is the pressure exerted on earth by the force of gravity pulling the air towards the earth's surface. Where air is rising from the surface, will the atmospheric pressure be increased or decreased?
The atmospheric pressure will be decreased.
Setup A
For this setup, we filled the plastic container with water and placed it on top of 8 styrofoam cups, each being stacked by two. Then, we placed 3 spots of red food coloring on the bottom, being careful while inserting the pipette and taking it out. After we placed the food coloring, we placed a water of hot water under the middle spot. This caused the middle spot to rise up and have low pressure. The area of high pressure was on the outside of the left and right areas. After we were finished, we dumped out the water and began Setup B.
Setup B
We repeated filling up the structure from Setup A, but this time, we put 2 cups of hot water under the left and right food dyes. The left and right areas then became areas of low pressure, whereas the areas of high pressure were near the middle spot.
Setup C
Rather than having three drops of food coloring, we only put two. Along with this, we also got a blue ice cube to put on the opposite side of the drops of food coloring. We set two cups of hot water underneath the red food coloring and they became areas of low pressure. However, there was an area of high pressure near the ice cube.
1. During the lab, what effect did the cups of hot water have on the density of the water directly above them?
It made the water less dense.
2. What happened as a result of this change?
The red dye would slowly begin to rise.
3. A house has a glass "sun space" attached to its south side, which is just a space all around the house, next to the outside wall that holds air. Vents allow air to flow from the house into the sun space, and vice versa. Describe the direction air flow as the air in the sun space is warmed by the Sun.
The hot air would go up, and the cold air would seep out.
4. You may have noticed convection cells in a pot of boiling macaroni. Describe the direction of water flow in the pot. The hottest part of the burner is beneath the center of the pot.
The water flow will go up and around.
5. Which situation would result in a decrease in atmospheric pressure at the earth's surface.? Identify the correct answer.
A- air gets hot and begins to rise
6. Go back to the three diagrams you constructed in your lab. label the sops in teach diagram that became areas of lower pressure.
Setup A: In the middle red dye.
Setup B: In the left dye and right dye.
Setup C: In the middle and right dye.
7. Above which area would the air become hotter in the afternoon? Identify the correct answer.
A- a parking lot with lots of blacktop pavement.
8. Above which area would you find the lowest air pressure?
A- the parking lot.
9. Based on this arrangement, would you expect a breeze to blow toward the parking lot, or away from it? Why?
A breeze would blow toward the parking lot.
10. From your knowledge of onshore and offshore breezes, explain why the wind would blow in from the sea toward the land during the afternoon.
The low pressure from the ground would go towards the sea, whereas the high pressure would go towards the land.
11. A "monsoon effect" may happen in the summer as air over a continent becomes much warmer than air over the ocean. Fill in the blanks in the following statements:
A: As air over the continent becomes hotter, it will begin to rise.
B: This causes lower pressure over the continent.
C: The flow of air will be toward the center of the continent.
12. Think globally now. Which region in our atmosphere is heated most intensely by the sun? Identify the correct answer.
C- the equatorial region.
13. As air near the equator rises, does this become an area of higher or lower pressure?
This area becomes an area of lower pressure.
14. What moves in to replace the rising air?
Cooler air moves in to replace the rising air.
15. Number the following stages of atmospheric circulation (1-4) in the order in which they are most likely to occur.
16. If hotter air rises, why is air that is closer to the Earth's surface warmer than the air high above it?
Conduction and the layers of the surface cause it to be warmer.
17. Wind is considered to be a form of "solar energy". Explain why.
Since the sun warms up the earth, this causes the earth to heat up the wind. An area of low pressure develops, and cold air begins to rise. Then, wind comes in.
It made the water less dense.
2. What happened as a result of this change?
The red dye would slowly begin to rise.
3. A house has a glass "sun space" attached to its south side, which is just a space all around the house, next to the outside wall that holds air. Vents allow air to flow from the house into the sun space, and vice versa. Describe the direction air flow as the air in the sun space is warmed by the Sun.
The hot air would go up, and the cold air would seep out.
4. You may have noticed convection cells in a pot of boiling macaroni. Describe the direction of water flow in the pot. The hottest part of the burner is beneath the center of the pot.
The water flow will go up and around.
5. Which situation would result in a decrease in atmospheric pressure at the earth's surface.? Identify the correct answer.
A- air gets hot and begins to rise
6. Go back to the three diagrams you constructed in your lab. label the sops in teach diagram that became areas of lower pressure.
Setup A: In the middle red dye.
Setup B: In the left dye and right dye.
Setup C: In the middle and right dye.
7. Above which area would the air become hotter in the afternoon? Identify the correct answer.
A- a parking lot with lots of blacktop pavement.
8. Above which area would you find the lowest air pressure?
A- the parking lot.
9. Based on this arrangement, would you expect a breeze to blow toward the parking lot, or away from it? Why?
A breeze would blow toward the parking lot.
10. From your knowledge of onshore and offshore breezes, explain why the wind would blow in from the sea toward the land during the afternoon.
The low pressure from the ground would go towards the sea, whereas the high pressure would go towards the land.
11. A "monsoon effect" may happen in the summer as air over a continent becomes much warmer than air over the ocean. Fill in the blanks in the following statements:
A: As air over the continent becomes hotter, it will begin to rise.
B: This causes lower pressure over the continent.
C: The flow of air will be toward the center of the continent.
12. Think globally now. Which region in our atmosphere is heated most intensely by the sun? Identify the correct answer.
C- the equatorial region.
13. As air near the equator rises, does this become an area of higher or lower pressure?
This area becomes an area of lower pressure.
14. What moves in to replace the rising air?
Cooler air moves in to replace the rising air.
15. Number the following stages of atmospheric circulation (1-4) in the order in which they are most likely to occur.
- Uneven heating
- Area of low pressure develops
- Convection (air rises)
- Wind (movement of air)
16. If hotter air rises, why is air that is closer to the Earth's surface warmer than the air high above it?
Conduction and the layers of the surface cause it to be warmer.
17. Wind is considered to be a form of "solar energy". Explain why.
Since the sun warms up the earth, this causes the earth to heat up the wind. An area of low pressure develops, and cold air begins to rise. Then, wind comes in.