Science EQ: What causes the wind to blow? Do Now: 3-4

1. ScienceEQ: What causes the wind to blow?Do Now: 3-4 LG: Explain the difference between air pressure and wind direction? Describe global wind patterns. HW: Study Global Wind notes, Review quiz correct answers. 15-3 Dir. Reading check Friday 1. Take out blue and read colored pencils/markers Today ~ papers back – make-up work?? ~ Visual Organizer: Global Winds

2. What causes winds? horizontal movement area of high to low pressure. Unequal heating of atmosphere = different temps Different temps = different air pressure High Pressure Low Pressure Low Pressure WIND WIND Earth’s Surface

3. Global Winds Winds that blow steadily from specific directions are global winds. Created by unequal heating of Earth’s surface. Warm air rises at the equator and falls at the poles.

4. Air Rises @ EquatorAir Sinks @ Poles • You know… • Warm air rises = less dense • Cool air sinks = more dense • Now understand… • Warm air = less dense = low pressure • Cool air = more dense = high pressure

5. Measuring Wind 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. Wind Vane Anemometer – The cups catch the wind, turning faster when the wind blows faster.

6. Info… via Video… 

7. Global Winds… cont… • The movement of air between the equator and the poles produces global winds. • The way that Earth’s rotation makes winds curve is called the coriolis effect. = pattern of the Global Winds

9. Global Wind Belts The five global wind belts are 1. doldrums 2. horse latitudes 3. trade winds 4. prevailing westerlies 5. polar easterlies.

10. Jet Streams Bands of high speed winds Upper troposphere and lower stratosphere Blow from west to east at speeds of 200-400 km/hr. Help airplanes save fuel and time when traveling east.

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

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

13. Horse Latitudes • High pressure areas… 300N and 300S • Very week winds

14. Wrap UP!

15. 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! Local winds are winds that blow over short distances. They are caused by unequal heating of Earth’s surface within a small area. 2 Types of local winds: sea breezes and land breezes

16. 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).

17. 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).