6.9B verify through investigations that thermal energy moves in a predictable pattern from warmer to cooler 6.5B recognize that a limited number of elements comprise the largest portion of oceans and atmosphere8.10A recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents

• How do they work?

• Due to the background color of this ppt, the notes you need to take are in yellow!

• Surrounding the Earth is a gases envelope, the atmosphere

A. It is mainly composed of a few limited elements:

• Nitrogen ~78%

• Oxygen ~21%

• Argon, Carbon, Neon, Helium, Hydrogen, & Krypton ~1%

B. Is a complex and dynamical, physical and chemical system.

• Dynamical: the processes of evaporation, condensation, precipitation

• Physical: the transfer of heat from the Sun to the Earth’s surface

• Chemical: the transformation and production of gases, such as ozone through chemical reactions of atmospheric gases.

• While the atmosphere extends hundreds of kilometers, more than half of its mass is about 6 km above the surface, in the troposphere

• If more than half of the mass is located in the troposphere, does this mean that air has weight?

Yes!

• Think back to when we learned about the Sun heating the Earth.

• Do the sun’s rays hit the Earth evenly?

• The atmosphere to be heated differently

• The land and water to be heated differently

• All 3 of these things: solid (land), liquid (water) and gas (air) have different densities andtherefore hold and pass along heat differently!

The more dense an object is, the more tightly packed the atoms are. Less dense objects have fewer molecules in the same amount of space.

Can density “change”?

Yes!

As things such as air heat up, the molecules start to move and need more space. This movement of the molecules increases the volume and therefore less matter is contained in the same space.

This is why hot air rises!

•Wind patterns are caused by air’s properties:•Cool air sinks•Warm air rises•Density changes as the temperature changes!

•Forms convection currents

• Wind is the movement of air as a result of different air pressure• The greater the pressure difference, the stronger the wind

• The air around you has weight, and it presses against everything it touches.

• That pressure is called atmospheric pressure, or air pressure.

• It is the force exerted on a surface by the air above it as gravity pulls it to Earth.

• pressure = force/area

• Wind (air) always moves from high pressure to low pressure (this key, underline it!!!)

• Air moves because of an imbalance in the forces acting on the air molecules.

• Wind is the atmosphere's way of trying to bring the interaction of these forces into a balance; an equilibrium.

• However, the factors that cause the imbalance are constantly changing so the balance is never achieved, so the air molecules move, which is wind.

• Watch the wind move today!

• http://hint.fm/wind/

Latitude is on the left and Longitude is on the right

A. Wind travels in “Pressure belts”, which are low or high pressure areas which lie parallel to latitudes.

• On the earth's surface, there are seven pressure belts. They are the Equatorial Low, the two Sub-tropical Highs, the two Sub-polar Lows, and the two Polar Highs.

• There is a pattern of alternate high and low pressure belts

• This is due to the spherical shape of the earth—different parts of the earth are heated unequally.

• The winds also do not flow in straight lines, but curve around the Earth.

Coriolis Animation

• 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

The Coriolis Effect

• Local winds- generally move short distances and can blow from any direction.

Air Cools Down

Cold

Air S

inks

Wind Blows Toward Coast

Warm Air Rises

Wa

rm A

ir R

ise

s

Cold Air Sinks

Air Cools Down

Wind Blows Away from the Coast

•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.

•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.

•Global winds- are part of a pattern of air flow that moves across the Earth.•Winds carry heat north from Earth’s equator•Winds carry colder air south toward the equator.

• Coriolis and other factors combine to produce a pattern of wind belts around the earth

• Major wind belts:• Trade winds• Westerlies • Easterlies

• The names of the types of winds on the next few slides are in red.

• Then draw the direction of the winds, using arrows

•Called trade winds because early sailors used the winds to sail from Europe to America•Blow at 30o latitude to the equator.•Label the equator, and the trade winds.•The wind movement arrows are done for you for this one

•Between 30o and 60o

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•Label the westerlies and draw arrows on your globe

•Between the poles and 60o 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•Label on your globe!

•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.

• Sailors noticed the stillness of the rising (and not blowing) air near the equator and gave the region the depressing name "doldrums."

•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

• This area 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.)

• So wind moves around on Earth, especially due to the uneven heating received from the Sun

• How does this really effect Earth, besides WIND?

• Climates!

•Most rainforests are near the equator because this is where the air is rising (because it is heated), creating clouds and rain.

Most deserts are at 30o

N and S Latitude because the air is sinking, loosing the

moisture, drying it out.

• Winds animation (explains rainfall and biomes too)

• http://www.kevinflint.org/ppt/chap5/Animations/global_circ_anim.html