1. Weather Wind May 21, 2008

2. Wind A wind is the horizontal movement of air from an area of high pressure to an area of low pressure. All winds are caused by differences in air pressure. What causes most differences in air pressure? –Unequal heating of the atmosphere

3. Measuring Wind Winds are described by their direction and speed. The name of a wind tells you where the wind is coming from. For example, a sound wind blows from the south toward the north. A north wind blows to the south. Speed is measured with an anemometer. An anemometer has cups mounted on spokes that spin on an axle. The force of the wind turns the axle. A speedometer attached to the axle shows the wind speed.

4. Wind-Chill Factor Wind-chill factor is increased cooling caused by wind. Felt due to the wind blowing over skin removes body heat. –What type(s) of heat transfer takes place? Conduction and convection

5. Local Winds Local winds are winds that blow over short distances. Local winds are caused by __________. –Difference in pressure caused by ________ –Unequal heating of Earth’s surface within a small area.

6. Sea Breeze During the day land heats up faster than water. This causes lower pressure over land Wind moves air from over the water (high pressure) to over the land (low pressure)

7. Land Breeze At night the situation reverses. Land cools more quickly than water creating a high pressure Air flows from over land to over water

8. Monsoons Sea and land breezes over a large region that change direction with the seasons are called monsoons.

9. Global Winds Global winds are effected by the combination of two causes: –Global convection currents –Coriolis effect

10. Closure What is wind? What causes wind? How is wind measured? Describe how a sea/land breeze is formed. What is the difference between a sea/land breeze and a monsoon? What are global winds and how are they formed?

11. Homework Wind – Assignment Weather Quiz Friday Weather Test Tuesday