1. Unequal Heating, Air Pressure and Winds

2. Atmosphere
Atmosphere: a mixture of gases that surrounds Earth: acts like a blanket
Contains oxygen
Protects from sun
Keeps heat in
Protects from meteors

3. Composition of Troposphere
Nitrogen=78%
Oxygen=21%
Other 1%=water vapor, CO2 and other

4. Weather Factors

5. Greenhouse Effect
These gases absorb the heat and act as a “blanket” to keep Earth warm.
Some greenhouse gases: water, methane, carbon dioxide.

6. Air Pressure Review Air has mass. Air takes up space. Air has density.
Air pressure is the weight of a column of air pressing down on an area.

7. Atmosphere/Pressure Pressure strongest at surface-more air above you
*as altitude (height above surface) increases, air pressure decreases
Stack of books

8. Air Pressure
As Air Pressure decreases, so does density.

9. Convection
Currents!

10. Heating and Cooling of Land and Water Mystery…Can You Help Solve It?

11. The Teacher Has Performed An Experiment and Asks That YOU Help Make Some Conclusions About the Data or Information Gathered.

12. Experiment Materials and Procedures: The Teacher Used A Thermometer, A Heat Lamp, A Cup of Sand, and A Cup of Water to Find the Temperatures of Both the Sand and The Water Over Two Hours.

13. DATA FROM THE EXPERIMENT
TEMPERATURES OF THE SAND
The First Hour It Was Heating Up & The Second Hour It Was Cooling Down
15 Minutes
30 Minutes
45 Minutes
1 Hour
68 Degrees
74 Degrees
88 Degrees
93 Degrees
76 Degrees
TEMPERATURES OF THE WATER
71 Degrees
83 Degrees
89 Degrees
87 Degrees
81 Degrees
77 Degrees
73 Degrees

14. TURN AND TALK! Answer the Questions Cooperatively.

15. CONCLUSION
Land Heats Up And Cools Down Faster Than Water! During the day, land heats faster than a body of water, so the air above the land becomes warmer. The warm air expands and creates a low-pressure system. The cooler air above the body of water blows inland and under the warm air. At night, the opposite happens.

16. Morning at the Beach
What is the temperature of the sand? Of the water?

17. Mid-Afternoon at the Beach
What is the temperature of the sand? Of the water?

18. Evening at the Beach
What is the temperature of the sand? Of the water?

19. Unequal Heating
What heats up quicker? What heats up slower? At night, which cools down quicker? Which cool down slower?

20. Unequal Heating
Land heats up and cools down quickly. Water heats up and cools down slowly.

21. Unequal Heating
Warm air rises and creates a low pressure system. Cold air sinks and creates a high pressure system.

22. Do You Remember How Convection Works?

23. Winds

24. The movement of air caused by differences in air pressure is called WIND.

25. What causes winds? Lots of difference
More of a difference in pressure = faster winds
Lots of difference

26. Have you ever flown a kite at the beach on a hot summer day?
Local Winds
Have you ever flown a kite at the beach on a hot summer day?
Even if there is no wind inland, there may be a cool breeze blowing in from the water toward the beach. This breeze is an example of local winds!

27. Local Winds Local winds are winds that blow over short distances.
They are caused by unequal heating of Earth’s surface within a small area.
4 types
sea breezes and land breezes
Mountain breeze and valley breeze

28. Why is the ocean colder than the land during the day and warmer than the land during the night?

29. Sea Breezes and Land Breezes

30. Sea Breeze (Morning)
Land heats up faster than water. Hot air over land rises (Low Pressure), cool air over water falls (High Pressure). Winds move from the water (High Pressure) to the land (Low Pressure).

31. Land Breeze (Evening)
Land cools off faster than water. Cool air over land falls (High Pressure), warm air over water rises (Low Pressure). Winds move from the land (High Pressure) to the water (Low Pressure).

32. Let’s Draw Land and Sea Breezes…

33. Let’s Draw Land and Sea Breezes…

34. Animation of Sea Breeze & Land Breeze

36. Valley Breeze (Day)
During the day the sun warms the air slopes, creating a valley breeze…
at nightfall, the air along the mountain slopes cools…

37. Mountain Breeze (Night)
This cool air moves down the slopes into the valley, producing a mountain breeze!

38. Let’s Draw Mountain and Valley Breezes

39. Global Winds
Created by unequal heating of Earth’s surface.

40. Global winds Warm air rises from the equator and sinks at the poles.
Warm air = less dense
= low pressure
Cool air = more dense
= high pressure

41. Global Winds… cont…
The movement of air between the equator and the poles produces global winds.
Coriolis effect produces patterns of air circulation called global winds.

42. GLOBAL WIND PATTERNS

43. Coriolis Effect.
As the Earth rotates, winds and currents move in a curved path, called the coriolis effect.

45. Global Wind Belts Major global wind systems:
Polar easterlies, westerlies, and trade winds.

46. Doldrums Where the trade winds meet around the equator
Very little wind because the warm air rising = low pressure

47. Horse Latitudes
High pressure areas… 300N and 300S
Very weak winds

48. Jet Streams Bands of high speed winds
Upper troposphere and lower stratosphere
Blow from west to east at speeds of km/hr.
Help airplanes save fuel and time when traveling east.

49. Atmosphere

50. Anemometer- a device used to measure wind speed
Anemometer- a device used to measure wind speed. Wind vanes measure wind direction.

51. Study Jams Video- Air Pressure and Wind http://studyjams. scholastic

52. Measuring Wind Winds are described by their direction and speed.
Wind Vane
Measuring Wind
Anemometer – The cups catch the wind, turning faster when the wind blows faster.
Winds are described by their direction and speed.
Wind direction is determined with a wind vane – points in the direction the wind is moving!
Wind speed is measured with an anemometer.
The increased cooling that a wind can cause is called the wind chill factor.