2. Winds

3. Learning Objectives  Explain how scientists describe and explain winds.  Distinguish between local winds and global winds and identify major global wind belts.

4. Moving Objects Wind is the movement of air parallel to Earth’s surface.

5. What Causes Wind? Air expands and becomes less dense; pressure decreases Cooler, denser air flows under the warmer air

6. What Causes Wind? How do the properties of air compare from the left to the right of this windsurfer? temperature pressure density pressure temperature Word Bank: lower higher higher lower higher

7. Measuring Wind Properties Winds are described by their direction and speed. wind vane anemometer

8. Windchill Factor Windchill factor = increased cooling caused by wind WIND hot day cold day

9. Local Winds Local winds blow over short distances. sea breeze land breeze

10. Global Winds Global winds blow steadily from specific directions over long distances.

11. The Coriolis Effect The Coriolis effect is the way Earth’s rotation makes winds curve. without Coriolis effect with Coriolis effect

12. Global Wind Belts horse latitudes doldrums trade winds polar easterlies prevailing westerlies E A B D C

13. Student Worksheet Answers