day 42 investigation 8 part 2 what causes wind. convection chamber review conclusion warm,...
TRANSCRIPT
Day 42
Investigation 8 part 2
What Causes Wind
Convection Chamber Review
Conclusion
Warm, less-dense air rose; Cooler, denser air sank
Creates a convection cell
Air sinks because it is denser
Air warmed by candle rose to the top because it is less dense
Air is cooled at the top of the chamber because of the ice
Review Convection Cell on EarthWhere on Earth’s surface could a convection cell develop?
Where Earth’s surface is warm
•Desert
•Tropical ocean
What happens to air pressure
If warm air less dense and rises, what effect do you think that has on air pressure on the ground?
1. As air warms, it expands.
2. Air rises
3. There is less air pushing down
4. Air pressure decreases
What happens to air pressureIf cool air denser and sinks, what effect do you think that has on air pressure on the ground?
1. As air cools, it contracts.
2. Air sinks
3. There is more air pushing down
4. Air pressure increases
Wind
• How can air move sideways across the surface of the Earth?
Wind?
• How is wind made?–Differential heating of Earth’s surface–Energy transfer (radiation, conduction, convection)–Air pressure–Density
• Cause wind?
Wind Concepts
• Differential heating and cooling affects energy transfer to and from the atmosphere
• Warm air expands and is less dense
• Cool air contracts and is denser
• Rising warm air and sinking cool air produce convection currents
Wind Concepts (part 2)
• Dense air produces high-pressure areas, less-dense air produces low-pressure areas
• Differences in atmospheric pressure causes air to move
• Air moving across Earth’s surface is wind
Differential heating and cooling off affects energy transfer to and from the atmosphere
Warm air expands and becomes less dense
Cool air contracts and becomes denser
Rising warm air and sinking cool air produce convection currents
High pressure area
Low pressure area
Wind Concepts
Differences in atmosphere pressure causes air to move
Air moving across Earth’s surface is wind
Multimedia
• Watch the different types of local winds.
• On pages 48 and 49 of the student lab book draw an illustration of the local winds after previewing the multimedia.
• Local weather conditions influence local winds
Which absorbs and releases solar energy faster, landmasses or water?
Energy transfer to and from the air in the atmosphere:1. Conduction (air molecules make contact with land
and water surfaces)
2. Reradiation of energy from the surface
• What happens to air when it is heated?
Air expands and
becomes less dense
What happens to air pressure over the land when air warms and expands? Pressure decreases, local
low pressure forms
Wind
• The horizontal movement of air from an area of high pressure to an area of lower pressure
Naming Local Winds• Local winds are
named based on the direction they come from
• A North wind is blowing from the North to the South
Sea Breeze
• Occurs during the day.
• The flow of air from an ocean or lake to the land.
Land Breeze
• Occurs at night
• The flow of air from land to a body of water.
Valley Breeze
Occurs during the day when air over the mountains heats and rises
The flow of air from the valley up through the mountain
Mountain Breeze
Occurs at night when air cools high in the mountains and sinks into valleys
Labels and Arrows
Visualization Exercise 8.3
Resources, P. 54
Color, Labels, and Arrows
Visualization Exercise 8.4
Images: CD-Rom
Arrows, Color and Real vs Diagram
Visualization Exercise 8.5
Resources, P. 58
Reading
• Starting on page 53 of your resource book read “Where the Wild Winds Blow”.
• Answer the “Think Questions” on page 55.