Questions of the Day Describe how wind is created. What happens to air pressure as I hike up a mountain? What instrument measures air pressure?

Global and Local Winds

Wind is the movement of air caused by differences in air pressure Air Movement Wind is the movement of air caused by differences in air pressure The greater the difference, the faster the wind moves

Differences in air pressure are caused by the uneven heating of Earth Uneven heating produces pressure belts which occur every 30° latitude

As warm air rises at the equator and moves toward the poles, it cools Pressure Belts As warm air rises at the equator and moves toward the poles, it cools As it cools, some of the air sinks around 30° north and south of the equator

At the poles, cold air sinks and moves towards the equator Pressure Belts At the poles, cold air sinks and moves towards the equator Around 60° north and south, the air begins to heat up and rise

Coriolis Effect Because the Earth rotates, and consists of a mixture of land and sea, the Coriolis Effect exists The Coriolis Effect is the movement of particles (such as air) to the right in the Northern Hemisphere How about the South? They move to the left

Coriolis Effect

Coriolis Effect • Coriolis Effect – Rotation of the Earth causes moving air and water to change directions • Northern Hemisphere winds curve to the right • Southern Hemisphere winds curve to the left. http://www.youtube.com/watch?v=mcPs_OdQOYU

These are polar easterlies, prevailing westerlies, and trade winds Global Winds The combination of pressure belts and the Coriolis Effect cause global winds These are polar easterlies, prevailing westerlies, and trade winds

30 60 90 Warm Moist Air Rises

30 60 90 Warm Moist Air Rises Cool Dry Air Sinks

90 30 60 Cold Moist Air Rises Cool Dry Air Sinks Warm Moist Air Rises 60 90 Warm Moist Air Rises Cool Dry Air Sinks Cold Moist Air Rises Cold Moist Air Rises

90 30 60 Cold Moist Air Rises Cool Dry Air Sinks Warm Moist Air Rises 60 90 Warm Moist Air Rises Cool Dry Air Sinks Very Cold Air Sinks Cold Moist Air Rises Cold Moist Air Rises Very Cold Air Sinks

L H 90 30 60 Cold Moist Air Rises Cool Dry Air Sinks 60 90 Warm Moist Air Rises Cool Dry Air Sinks Very Cold Air Sinks Cold Moist Air Rises Cold Moist Air Rises Very Cold Air Sinks

Wind Moves from HIGH to LOW 30 60 90 Wind Moves from HIGH to LOW

Objects are deflected to the RIGHT in the Northern Hemisphere 30 60 90

Wind belts that extend from the poles to 60° latitude Polar Easterlies Wind belts that extend from the poles to 60° latitude Formed from cold sinking air moving from the poles creating cold temperatures

Prevailing Westerlies Wind belts found between 30° and 60° latitude Flow towards the poles from west to east carrying moist air over the United States

Winds that blow from 30° almost to the equator Trade Winds Winds that blow from 30° almost to the equator Called the trade winds because of their use by early sailors

Doldrums Located along the equator where no winds blow because the warm rising air creates and area of low pressure

Most deserts on the Earth are located here because of the dry air Horse Latitudes Occur at about 30° north and south of the equator where the winds are very weak Most deserts on the Earth are located here because of the dry air

Separates warm air from cold air Jet Stream The jet streams are narrow belts of high speed winds that blow in the upper troposphere and lower stratosphere Separates warm air from cold air

Jet Streams Jet Streams form at latitudes where wind systems come together High speed westerly winds form high above the surface

What brings certain weather phenomenon? El Nino La Nina occurs when the surface temperature rises above the normal water temperature in the Equatorial Pacific Ocean creating more humidity in the atmosphere Known to increase number of hurricanes Occur more frequently (every 3-7 years) occurs when the surface temperature falls below the normal water temperature in the Equatorial Pacific Ocean creating a more dry atmosphere Known to create drought conditions

Generally move short distances and can blow in any direction Local Winds Generally move short distances and can blow in any direction Caused by geographic features that produce temperature differences

Local Winds • Cover short distances • Blow from any direction • 2 Types of Local Winds – Sea Breezes- from sea to land – Land Breezes – from land to sea

Air moves from the ocean to the land creating a sea breeze Sea Breezes High pressure is created over the ocean during the day and low pressure over land due to uneven heating Air moves from the ocean to the land creating a sea breeze

Land Breezes Low pressure occurs over the ocean during the night and high pressure over land due to the uneven heating of earth This causes wind to move from the land to the ocean creating a land breeze

What’s the difference?

Question 1 What causes winds?

Answer Winds are caused by the uneven heating of Earth’s surface, which causes pressure differences

What are the three types of global winds? Question 2 What are the three types of global winds?

Answer Polar Easterlies Westerlies Trade Winds

What is the difference between a land breeze and a sea breeze? Question 3 What is the difference between a land breeze and a sea breeze?

Answer Sea breezes occur during the day when the land is warmer than water and a land breeze occurs at night when the water is warmer than land

Global Wind Patterns Flipbook Cut out the outline map. Set aside. Fold 2 sheets of paper long ways in half Cut both pieces in half long ways along the fold lines. Keep three strips of paper. Stack the papers on top of each other.

Global Wind Patterns Flipbook Shift the papers over so that there is approximately one cm between each one At the middle of the stack fold the papers under so that each tab is about a cm across Staple Glue outline map on front tab

Global Wind Patterns Flipbook Fill in an label the global wind patterns using the following colors. Use the same colors when writing the name of the wind on the tabs Doldrums-red Tradewinds-orange Horse latitudes-yellow Westerlies-green Polar easterlies-blue

Global Wind Patterns Flipbook Draw arrows using black to indicate the directions of the winds movement due to the Coriolis Effect On the tabs above each item (above the terms) give a detailed description of the concept