17
What is wind? Wind is the horizontal movement of air from an area of high pressure to an area of lower pressure.

What is wind?

Embed Size (px)

DESCRIPTION

What is wind?. Wind is the horizontal movement of air from an area of high pressure to an area of lower pressure. Because air is fluid, it can move easily from place to place. Differences in air pressure cause the air to move. - PowerPoint PPT Presentation

Citation preview

Page 1: What is wind?

What is wind?

Wind is the horizontal movement of air from an area of high pressure to an area of lower pressure.

Page 2: What is wind?

Because air is fluid, it can move easily from place to place. Differences in air pressure cause the air to move.

These differences in air pressure are caused by the unequal heating of the atmosphere.

Page 3: What is wind?

Convection currents form when an area of Earth’s surface is heated by the sun’s rays.

How would this effect winds?

Page 4: What is wind?

Air expands over heated surfaces and becomes less dense, causing its air pressure to decrease.

In a nearby area that is not heated as much, the air is cooler, denser and has higher air pressure.

Page 5: What is wind?

The cool, dense air with higher pressure flows underneath the warm, less dense air forcing the warm air to rise.

Winds are described by their direction and speed.

Wind vanes determine wind direction. The name of the wind indicates where it’s coming from.

Page 6: What is wind?

Wind speed is measured with an anemometer.

Page 7: What is wind?

The increased cooling a wind can cause is called the wind-chill factor.

If the temperature outside is 20 degrees Fahrenheit with a wind speed of 30 miles per hour, the wind-chill makes it feel like 1 degree.

Page 8: What is wind?

Challenge Make an anemometer.MATERIALS: 5 3-ounce Paper Cups 2 Straight Plastic Soda Straws 1 Straight Pin or Push Pin 1 Sharp Pencil With An Eraser Safety Scissors Paper Hole Punch Small Stapler Ruler

Page 9: What is wind?

Local WindsLocal winds blow over short distances.

They are caused by the unequal heating of Earth’s surface within a small area.

Local winds only form when large-scale winds are weak.

Page 10: What is wind?

Sea BreezeOccurs along the shore of a large body of water.

More energy is needed to warm up this water than an equal area of land.

This results in air over land becoming warmer than the air over water.

Page 11: What is wind?

Global WindsGlobal winds blow steadily from specific

directions over long distances.

They are created by the unequal heating of Earth’s surface and occur over a large area.

How does the sun’s rays strike Earth?

Page 12: What is wind?

Where is the temperature the warmest? The lowest?

Page 13: What is wind?

Temperature differences between the equator and the poles produce giant convection currents in the atmosphere.

Warm air, with less density and pressure, rises at the equator and cold air, higher pressure, sinks at the poles.

Page 14: What is wind?

This pressure difference causes winds to blow from the poles toward the equator at Earth’s surface.

However, air flows away from the equator toward the poles higher up in the atmosphere

Page 15: What is wind?

The Coriolis EffectThe way Earth rotates causes the

winds to curve.

Because of the Coriolis effect, global winds in the Northern Hemisphere gradually turn toward the right.

Page 16: What is wind?
Page 17: What is wind?

http://www.phschool.com

Course ContentWeb Codescfp 4023

Click STARTRead the Introduction