Atmosphere and Winds E4.p2X-A,F, I. CHARACTERISTICS OF THE ATMOSPHERE

Atmosphere and Winds

E4.p2X-A,F, I

CHARACTERISTICS OF THE ATMOSPHERE

Composition of the Atmosphere• Atmosphere-mixture of gases around the Earth– 78% Nitrogen-(released from decay/eruptions)– 21% Oxygen– 1% Other- (Carbon Dioxide, Argon)

• Can also contain liquid and solids– Water vapor– Dirt, smoke, ash, etc Nitrogen

OxygenOther

Pressure

• Air Pressure- measure of force which air molecules push on a surface

• Changes throughout the atmosphere

• Atmosphere is held around the planet by gravity

• Gravity pulls at the air molecules, giving them greater weight the closer they are to the Earth

• Altitude- height of an object above Earth’s surface– As altitude increases, pressure decreases

Layers of the Atmosphere

• Troposhere-– Lowest layer– 90% of atmosphere’s mass

• Stratosphere-– Second lowest layer– Extremely cold, moisture-less, – Contains the Ozone Layer

Layer cont...• Mesosphere-– Second highest layer– Coldest layer ( -93 degree Celsius)– Contains large wind storm

• Thermosphere-– Uppermost layer – Highest temps due to spread of particles

A Fifth Layer?• Ionosphere-– Upper Meso and Lower Thermospheres– Absorbs gamma and X-rays– Reflects radio waves and radiant energy in colors

Assignment Day 1• 1.What is the connection between altitude and

pressure?

• 2. What is the relationship between gravity and pressure?

• 3. Define- atmosphere, air pressure, altitude

• 4. Draw a Diagram of the Layers of the Atmosphere– Include: troposphere, stratosphere, mesosphere,

ionosphere, and thermosphere

HEATING THE ATMOSPHERE

Do Now

• What does this pie chart represent?

• Gases of the Atmosphere!– 78% N– 21% O– 1% other

Series1

• Temperature- amount of energy in a given space

• Please Draw

Energy in the Atmosphere

• What are the three ways thermal energy is transferred?

• Convection• Conduction• Radiation

Radiation• How Earth receives Sun’s energy• Sun’s Radiation:

50%

25%

20%

5%

Absorbed by Earth's Surface

Reflected by Clouds

Absorbed by Ozone and Gases

Reflected by Earth's Surface

Greenhouse Effect• Greenhouse Effect- atmosphere traps thermal

energy

Atmosphere!Sun’s Radiation

• Greenhouse Gases- Gases that raise the temp of the atmosphere– Ex: Carbon dioxide

• Global Warming- rise in avg global temps

• Radiation Balance- balance between incoming energy from the sun and outgoing energy into space– Planting trees helps maintain balance

Assignment Day 2• 1. What are the three types of thermal energy

transfer?• 2. Which type of thermal energy transfer is how

the Earth get’s energy from the sun?• 3. Which type of thermal energy transfer causes

winds? (Think of the circular motion)• 4. Please draw and label the greenhouse effect.• 5. Why does the planting of trees help with

radiation balance?

PRESSURE AND WINDS

Wind

• Which type of thermal energy transfer is the cause of wind?

• CONVECTION/CONVECTION CURRENTS!

• Wind- moving air– Wind and wind movements are causes by

differences in air pressure

Why Air Moves• Greater pressure, faster wind movement – Pressure caused by uneven heating of Earth

• High Pressure– Polar air is cold and dense– Cold, sinking air creates high pressure area

• Low Pressure– Equator air is warm and less dense– Rises and creates low pressure area

• Pressure difference causes air movement• Air generally moves from high to low pressure• Please Draw

Pressure Belts

• Low Pressure Belts-– Equator– 60 degrees N and S

• High Pressure Belts-– 30 degrees N and S– N and S Poles

Cause for Pressure Belts

• Pressure Belts AKA Convection Cells

• High Pressure– Warm air from Equator moves towards Poles– At about 30 degrees, air begins to cool and sinks

• Low Pressure– Cold air from Poles moves towards Equator– At about 60 degrees, air begins to warm and rises

Coriolis Effect• Coriolis Effect- Curving motion of objects and

wind due to Earth’s rotation• Winds don’t blow directly North or South– Affected by rotation

Types of Winds

• Trade Winds– Between equator and 30 degree both hemis

• Westerlies– Between 30-60 degrees in both hemis– Flow to the west, opposite of trade winds

• Easterlies– Between 60degrees and poles in both hemis– Cold, sinking air flows to the east

Types of Winds (cont)• Doldrums– low pressure at Equator where trade winds meet

• Horse Latitudes– 30 degree area of high pressure

• Jet Streams– Narrow belts of high speed winds (up to 500mph)

• Local Winds– Move short distances in any direction

Assignment Day 3

• 1. How does the Coriolis Effect affect winds?• 2. Where are the Doldrums and the Horse

Latitudes located at?• 3. What factor(s) cause wind?• 4. What is the difference between high

pressure and low pressure areas?• 5. What is the other name for the Pressure

Belts? Explain why this makes sense.