1. Winds (7.6)

2. Wind Notes Chapter 7.6
Winds are caused by differences in air pressure. They move from high pressure areas to low pressure areas.
The sun causes different air pressure therefore the ultimate source of energy that powers the wind.
What creates wind?

3. L H What creates Wind? Cold Air Warm Air High Pressure Low Pressure
More Dense Less Dense
The molecules like to move to a less crowded area. Their movement causes wind.
What creates Wind? L H

4. L Measuring Wind Wind Speed
Wind Direction
Wind speed is measured using an anemometer.
Is measured using a wind vane or wind sock. L

5. Measuring Wind
The name of the wind tells you where the wind is coming from. North wind comes from the North. N E W S L H
Location A
Location B
West wind blows from the west to the east.
Name: West wind Wind direction: East

6. L H H L East Wind Blows West North Wind Blows South Location B
Location A
Location A H N E W S
North Wind
Blows South L
Location B

7. What is the name of Each wind What Direction is the wind blowing?
Northwest Wind
Southeast
West Wind
East A. B. A. B.
Northeast Wind
Southwest
South Wind
North A. B.

8. What type of air pressure creates rain?
Low air pressure creates rain because all the water in the air rises and then cools creating rain clouds.

10. Local Winds
Local winds are winds that blow over short distances and are caused by unequal heating of Earth’s surface within a small area.
Ex: Sea breeze, land breeze,

11. Sea Breeze

12. Land Breeze

13. Mountain-Valley Breezes

14. Compressional Heating Winds (Santa Ana Winds, Chinooks, Foehn Winds)

15. Santa Ana Winds San Diego, October 2003

16. Global Winds
Winds that blow steadily from specific directions over long distances.
caused by unequal heating of Earth’s surface.

18. Coriolis Effect
The effect of Earth’s rotation on the direction of winds and currents.
Due to the spinning of the earth wind blows to the east and west instead of North and South.

19. Polar Easterlies Polar Easterlies
Wind belts that extend from the poles to 60° latitude
Formed from cold sinking air moving from the poles creating cold temperatures
Polar Easterlies
Strong polar winds due to low friction

20. Westerlies Westerlies Wind belts found between 30° and 60° latitude
Flow towards the poles from west to east carrying moist air over the Unites States
Westerlies

21. Trade Winds Trade Winds Winds that blow from 30° almost to the equator
Called the trade winds because of their use by early sailors
Trade Winds

22. Some of the air moves back towards the equator as it sinks...
Tradewinds:
Where do you think they got their name?
Who were these winds important to?

23. Doldrums
Located along the equator where no winds blow because the warm rising air creates and area of low pressure
Doldrums

24. There was an area that sailors avoided with their lives...
THE DOLDRUMS... is the area around the equator where the wind completely dies out... which meant death as soon as the fresh water ran out.

25. Horse Latitudes Horse Latitudes Horse Latitudes
Occur at about 30° north and south of the equator where the winds are very weak
Most deserts on the Earth are located here because of the dry air
Horse Latitudes
Horse Latitudes

26. Jet Stream
The jet streams are narrow belts of high speed winds that blow in the upper troposphere and lower stratosphere
Separates warm air from cold air
West to east

28. Isobaric Chart Showing the difference in air pressure for the United States.

29. High Pressure, Low Pressure combined with Local and Global winds is what creates weather.
Wind video 15 min

30. Question 1
What causes winds?

31. Answer
Winds are caused by the uneven heating of Earth’s surface, which causes pressure differences

32. What are the three types of global winds?
Question 2
What are the three types of global winds?

33. Answer
Polar Easterlies
Westerlies
Trade Winds

34. What is the difference between a land breeze and a sea breeze?
Question 3
What is the difference between a land breeze and a sea breeze?

35. Answer
Sea breezes occur during the day when the land is warmer than water and a land breeze occurs at night when the water is warmer than land

39. High Pressure, Low Pressure combined with Local and Global winds is what creates weather.
Wind video 15 min