1. Winds

2. What is Wind? The horizontal movement of air from High pressure to Low pressure. H  L Air moving up or down (vertical) is called a current

4. X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Cooler Air Warmer Air Molecules move faster and are farther apart. Molecules are close together and move slowly. Pressure is caused by the characteristics of the air Less Dense More Dense

5. Warm Air Rises Cool Air Sinks Warm Air Rising Cool Air Sinking Warm Air Rising

6. Convection Currents Warm Air Rising Cool Air Sinking

7. High Pressure Ok, High Pressure is 1.Dense (heavy) 2.Cool 3.Creates Clear Skies

8. Low Pressure Ok, Low Pressure is 1.Less Dense (heavy) 2.Warmer 3.Brings Lousy Weather

9. High Pressure = Happy Weather H Low Pressure = Lousy Weather L

10. In a high pressure area, air will (rise, sink) because the air is (less, more) dense. This is because the air is (cold, warm) and (rises, sinks). Therefore, clouds CANNOT form.

11. In a low pressure area, air will (rise, sink) because the air is (less, more) dense. This is because the air is (cold, warm) and (rises, sinks). Therefore, clouds are LIKELY to form.

12. There Are Two Kinds of Winds: Global and Local Global Winds are Winds that blow over long distances around the Earth. Local Winds are winds that blow a short distance.

13. Global Winds

14. Thus, radiation is more intense near the equator compared to the poles. For this reason, it’s warmer near the equator than at the poles. North Pole South Pole Why Do Different Parts of the Earth Have Different Temperatures? Equator

15. Global Thermal Temperatures

16. Air Rises at the Equator Air at the Equator is warm. Warm air rises. The Equator is a Low Pressure area.

17. What Happens to Rising Air at the Equator? At the Equator, air rises; As the air moves upward, it cools, The air begins to turn to move downward. Cold air sinks at the 30 o zone.

18. Winds blow from High Pressure to Low Pressure

19. Let’s Label Low Pressure 0 ° High Pressure 30 ° N High Pressure 30 ° S Low Pressure 60 ° N Low Pressure 60 ° S High Pressure 90 °N High Pressure 90 ° S

20. Why Don’t The Winds Blow in Straight Lines? Cold air from both the South Pole and North Pole blows towards the 60 o zone But the air doesn’t flow in a straight line

21. Coriolis Effect Since the earth rotates, winds do not blow directly from north to south or south to north. Winds curve They curve because the earth rotates or spins on its axis. The Coriolis Effect is the curving of winds due to the earth’s rotation.

22. The ball is going straight, but it looks like it is curving.

23. Local Winds Winds that blow short distances and in any direction (depending on pressure) Remember, winds always blow from areas of high pressure to low pressure.