Today’s Agenda… Get your clickers! Water Cycle Review Quiz Air Movement Notes

Air Movement Study Pack #10 Page 103

Today’s goals… I can explain why different areas on Earth receive different amounts of solar energy. I can describe the Coriolis effect. I can describe global winds and their affect on water. I can explain how land and water surfaces affect the wind.

Forming Wind Wind is the movement of air from an area of higher pressure to an area of lower pressure This is caused by the uneven heating of Earth’s surface

Heated Air Areas of Earth receive different amounts of radiation because the Earth is curved See Figure 15 Which areas receives the most direct sunlight? The least? Equator Poles

Heated Air At the equator air is heated and rises, forming a low pressure area As the air moves away from the equator it cools and sinks and most returns to the equator as trade winds, some flows on to the poles

The Coriolis Effect The coriolis effect makes the winds appear to be curving to the west, whether they are traveling to the equator from the North or the South This contributes to weather patterns as well as to where and when planes fly and ships sail See page 104, Figure 16 More

Doldrums The trade winds meet at the equator and move upward creating a calm area with little wind As the warm air moves upward it cools, causing rain

Prevailing Westerlies 30 – 60 degrees latitude The winds that flow toward the poles appear to curve from west to east Responsible for many of the weather movements across the US and Canada

Polar Easterlies The cool air flows away from the poles and is deflected from the east toward the west by the coriolis effect

Winds in the Upper Troposphere Jet streams are narrow belts of strong winds that blow near the top of the troposphere It helps move storms across the country Pilots also take advantage of the jet streams

Sea and Land Breezes Convection currents over areas where the land meets the sea can cause winds A sea breeze is created during the day because solar radiation warms the land more than the water

Sea and Land Breezes Warm air over the land rises, creating an area of low pressure Cool air over the water has higher pressure and flows toward the warmer, less dense air Sea breezes

Sea and Land Breezes The opposite occurs at night when land cools more rapidly than water The cool air over land moves toward the warmer air over the water (land breeze)

More about wind… BrainPop

Review Questions What causes wind? What surface winds move weather across the US? What deflects wind to the right north of the equator and to the left south of the equator? What winds do pilots take advantage of to save fuel and time? What type of wind is a movement of wind toward water?