IN THE TABLE OF CONTENTS AND ON THE NEXT CLEAN PAGE, TITLE IT: WIND NOTES WIND!

IN THE TABLE OF CONTENTS AND ON THE NEXT CLEAN PAGE, TITLE IT: WIND NOTES WIND!

Wind 8.10A recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents

Wind The Earth is in a constant battle to equalize its temperature. It never succeeds, because our planet is hotter in some places than in others.

Uneven heating causes The atmosphere to be heated differently The land and water to be heated differently

Wind Patterns Earth s air is always on the move Cool air sinks Warm air rises Forms convection currents

Convection Currents

Convection Currents in North America

What is air pressure? Air pressure is the force per unit of area exerted on the Earth s surface by the weight of the air above the surface.

Wind Wind is the movement of air as a result of different air pressure The greater the pressure difference, the stronger the wind Caused by unequal heating of the Earth

Pressure Belts Pressure belts are low or high pressure areas which lie parallel to latitudes.

Checkpoint! Latitude is on the left and Longitude is on the right

ASSOCIATED PRESSURE BELTS Rising air at the equator causes the equatorial belt of low pressure Descending air at about 30ºN and 30ºS causes the sub-tropical belt of high pressure Rising air at about 60ºN and 60ºS causes a midlatitude belt of low pressure Descending air at the poles causes the polar high pressure areas Polar high pressure Mid latitude low pressure Sub-tropical high pressure Equatorial low pressure Sub-tropical high pressure Mid latitude low pressure Polar high pressure

ASSOCIATED SURFACE WIND PATTERNS Winds always blow from high pressure to low pressure. They are deflected because of the Coriolis Force which come about because of the rotation of the earth. Winds in Northern Hemisphere are deflected to the right. Winds in the southern hemisphere are deflected to the left. These wind belts shift seasonally. Polar high pressure Mid latitude low pressure Sub-tropical high pressure Equatorial low pressure Sub-tropical high pressure Mid latitude low pressure Polar high pressure

Coriolis effect Global winds do not blow in straight lines The earth rotates as wind blows, making it seem as if the winds are curving Called the Coriolis effect Coriolis Animation Coriolis Effect Winds and the Coriolis Effect

Kinds of Winds Local winds- generally move short distances and can blow from any direction. Global winds- are part of a pattern of air flow that moves across the Earth.

Local Winds Land breezes and sea breezes occur because of the differences in heating of the land and water These differences create a (small) convection current

Warm Air Rises Cold Air Sinks Air Cools Down Warm Air Rises Wind Blows Toward Coast Air Cools Down Cold Air Sinks Wind Blows Away from the Coast Sea Breeze During the day, the land heats up more quickly than the sea. Above the land, warm air rises and the wind blows toward the coast. Land Breeze At night, the land cools down quickly while the sea stays warm. Above the sea, warm air rises and the wind blows away from the coast.

Day vs. Night 85 o 50 o 65 o 63 o Sea Breeze happens during the day when the land heats up more than the ocean Land Breeze happens during the night when the land cools off more than the ocean

Global Wind Patterns Winds carry heat north from Earth s equator Winds carry colder air south toward the equator.

Global Winds Coriolis and other factors combine to produce a pattern of wind belts around the earth Major wind belts: Trade winds Westerlies Easterlies

Trade Winds Blow at 30* latitude to the equator. (early sailors used the winds to sail from Europe to America) When cold air sinks, produces high pressure High pressure wants to move to an area of low pressure--the equator!! These winds that are blowing toward the equator are deflected west because of the Coriolis effect

Westerlies Between 30* and 60* latitude. Flows towards the poles. Helped ships return to Europe. Blows from west to east-- WESTERLIES Winds are turned toward the east by Coriolis effect

Easterlies Between the poles and 60* latitude. Cold air near poles sinks and flows back toward lower latitudes Coriolis shifts these winds to west Wind goes from East to west--easterlies

Columbus and Global Scale Winds Columbus was an expert sailor with a extraordinary knowledge of the global winds. He did not attempt to sail into the middle of the westerly winds, but rather turned south and used the Easterly Trade Winds to drive his ships across the Ocean. On the return voyage, he headed north and then used the westerlies to propel his ships back to Europe, stopping at the Azores on the way for much needed repairs.

Doldrums Near equator, between 0-30 degrees latitude (usually between 5 north and 5 south of the equator) Rising air, low pressure Cool air moves into area, warmed rapidly, and rises Warms so fast, air doesn t really move (no breeze) before it rises again.

Why are they named this? Sailors noticed the stillness of the rising (and not blowing) air near the equator and gave the region the depressing name "doldrums."

Doldrums All in a hot and copper sky, The bloody Sun, at noon, Right up above the mast did stand, No bigger than the Moon. Day after day, day after day, We stuck, nor breath nor motion; As idle as a painted ship Upon a painted ocean. - The Ancient Mariner

Horse Latitudes Between about 30 to 35 north and 30 to 35 south Weak winds Forms a belt of calm air Contributes to deserts in this area Latitude and Precipitation

Again, the name? This region of subsiding dry air and high pressure results in weak winds. Tradition states that sailors gave the region of the subtropical high the name "horse latitudes" because ships relying on wind power stalled; fearful of running out of food and water, sailors threw their horses and cattle overboard to save on provisions. (It's a puzzle why sailors would not have eaten the animals instead of throwing them overboard.)

Prevailing Wind Patterns

Global Wind Pattern 32 Global Wind Patterns

Rainforests of the World Most rainforests are near the equator because this is where the air is rising, creating clouds and rain.

Deserts of the World Most deserts are at 30 o N and S Latitude because the air is sinking, drying it out.

Map to color you need red and blue pencils

Imitate this information On your page, draw the arrows direction and location (where they are) Label the latitude lines as shown Do this with a regular pencil

Now let s add color!

Color your arrows!