The AtmosphereThe Atmosphere

BIGBIG Idea: Idea:

• The composition, structure, The composition, structure, and properties of Earth’s and properties of Earth’s atmosphere form the basis atmosphere form the basis of Earth’s weather and of Earth’s weather and climate.climate.

Who studies Who studies atmospheric atmospheric conditions?conditions?

•Meteorologists…Meteorologists…that’s that’s who!who!

•How would you describe How would you describe the difference between the difference between WEATHERWEATHER and and CLIMATECLIMATE??

I. Characteristics I. Characteristics of the of the

AtmosphereAtmosphere

• WeatherWeather = = day-to-day day-to-day changes inchanges in atmospheric atmospheric conditions.conditions.

•These conditions include:These conditions include:

•TemperatureTemperature

•Air movementsAir movements

•Moisture contentMoisture content

• ClimateClimate = = general general weather conditions weather conditions averaged over averaged over manymany (about 30) years(about 30) years

A. Composition of the A. Composition of the AtmosphereAtmosphere

• 78% Nitrogen78% Nitrogen• 21% Oxygen21% Oxygen• 0.9% Argon0.9% Argon• 0.1% Other0.1% Other

• OzoneOzone – protects us – protects us

from harmful UV from harmful UV (ultraviolet) rays(ultraviolet) rays

Damaged by CFCs Damaged by CFCs

(poisons in ACs(poisons in ACs

and refrigerators)and refrigerators)

Ozzy Ozone

• Have you Have you noticed the noticed the weather weather today?today?

• How would How would you you describe it?describe it?

B. Properties of the B. Properties of the AtmosphereAtmosphere

1)1)TemperatureTemperature

2)2)Air PressureAir Pressure

3)3)HumidityHumidity

1. Temperature1. Temperature

• measure of the measure of the average kinetic average kinetic energy of particles in a energy of particles in a materialmaterial

• more energy = moving faster more energy = moving faster = higher temperature= higher temperature

• measured with a thermometermeasured with a thermometer

2. Atmospheric (Air) 2. Atmospheric (Air) PressurePressure

•the ratio of the force of the the ratio of the force of the air to the area of the air to the area of the surface on which it pressessurface on which it presses

•the weight of the the weight of the atmosphere pressing down atmosphere pressing down on Earth’s surfaceon Earth’s surface

BAROMETERBAROMETER

• an instrument that an instrument that measures atmospheric measures atmospheric pressurepressure

a.a. Mercurial BarometerMercurial Barometer

b. Aneroid Barometerb. Aneroid Barometer

• Aneroid = ‘without liquid’ Aneroid = ‘without liquid’

3. Humidity3. Humidity

•the amount of water the amount of water vapor in the atmosphere vapor in the atmosphere at a given location on at a given location on Earth’s surfaceEarth’s surface

C. Layers of the C. Layers of the AtmosphereAtmosphere

- Based on Based on temperature temperature differences, scientists differences, scientists identify identify fourfour layers of layers of Earth’s atmosphereEarth’s atmosphere

- Each layer is separated Each layer is separated by a “pause”by a “pause”

•Visualizing the Layers of theVisualizing the Layers of the Atmosphere Atmosphere

1. Troposphere: 1. Troposphere: all all weather occurs hereweather occurs here

• Layer closest to Earth’s Layer closest to Earth’s surfacesurface

2. Stratosphere: 2. Stratosphere: where where most of the ozone ismost of the ozone is

3. Mesosphere: 3. Mesosphere: coldest coldest layer (-90°C )layer (-90°C )

4. Thermosphere: 4. Thermosphere: hottest hottest layer (over 2000°C); layer (over 2000°C); nitrogen and oxygen nitrogen and oxygen atoms absorb solar atoms absorb solar energyenergy

• Components of the AtmosphereComponents of the Atmosphere - Quiz - Quiz

II. Solar EnergyII. Solar Energy

A. Radiation:A. Radiation: all all forms of forms of energy that energy that travel through travel through space as space as waveswaves

What happens to solar What happens to solar energy that reaches energy that reaches

Earth’s surface?Earth’s surface?

1.1.reflected (sent in a reflected (sent in a new direction), ornew direction), or

2.2.absorbedabsorbed

•Why does Why does the inside of the inside of a closed a closed parked car parked car heat up, heat up, while the while the windows windows stay cool?stay cool?

B. Greenhouse Effect:B. Greenhouse Effect: atmosphere traps (long) atmosphere traps (long) infrared raysinfrared rays

• The Sun’s energyThe Sun’s energyis trapped is trapped inside.inside.

•What are the What are the ‘‘greenhouse gasesgreenhouse gases’ that ’ that trap heat within our trap heat within our atmosphere?atmosphere?

1.1.Water vaporWater vapor

2.2.Carbon dioxideCarbon dioxide produced by humansproduced by humans burning of fossil fuels burning of fossil fuels

(oil, gas, coal)(oil, gas, coal)

C. Heat Energy TransferC. Heat Energy Transfer

1.1. Convection: transfer of Convection: transfer of heat energy in heat energy in gases or gases or liquidsliquids due to density due to density differences.differences.

2. Conduction: transfer of 2. Conduction: transfer of heat energy through matter heat energy through matter from particle to particle; from particle to particle; most effective in most effective in solidssolids. .

3. Radiation: waves that 3. Radiation: waves that directly transport energy directly transport energy through through spacespace; brings ; brings HEATHEAT to our to our planet. planet.

III. WindsIII. Winds

• Created by uneven heat Created by uneven heat distribution at Earth’s surfacedistribution at Earth’s surface– The amount of energy The amount of energy reaching any given point on reaching any given point on Earth’s surface is controlled Earth’s surface is controlled by the by the angleangle of sunlight of sunlight striking the surfacestriking the surface

•What causes the What causes the amount of energy to amount of energy to vary?vary?

Hint: …Hint: …

•Our tilt, and the seasons!Our tilt, and the seasons!•Where on Earth will you Where on Earth will you receive receive moremore of the sun’s of the sun’s energy per unit area?energy per unit area?

•Where will you receive Where will you receive lessless??

• The Coriolis Effect: Earth’s The Coriolis Effect: Earth’s rotation causes winds to rotation causes winds to deflect (curve) to the right in deflect (curve) to the right in the Northern Hemisphere and the Northern Hemisphere and to the left in the Southern to the left in the Southern Hemisphere. Hemisphere.

• Same with waterSame with water

A. Global WindsA. Global Winds

Winds are named according to the direction FROM which they flow!

1. 1. Trade WindsTrade Winds – winds in both – winds in both hemispheres flowing hemispheres flowing towardstowards the equatorthe equator

between 30° (N and S) and 0° between 30° (N and S) and 0° latitudelatitude

a.a. DoldrumsDoldrums – weak and – weak and unpredictable air mix, 5° N and unpredictable air mix, 5° N and S of the equatorS of the equator

*winds *winds CONVERGECONVERGE here to form an here to form an area of area of LOWLOW pressure pressure

b.b. Horse Latitudes Horse Latitudes – very weak air – very weak air movement 30°- 35° N and Smovement 30°- 35° N and S

2. 2. WesterliesWesterlies – between 30° and – between 30° and 60° N and S. 60° N and S.

3. 3. Polar EasterliesPolar Easterlies – weak winds – weak winds at 60° N and S that flow away at 60° N and S that flow away from the poles.from the poles.

TICKET ITEM!!TICKET ITEM!!

•Why does warm air rise Why does warm air rise from the equator, and from the equator, and cold air sink at the cold air sink at the poles?poles?

4. Jet Stream4. Jet Stream – bands of high- – bands of high- speed high-altitude speed high-altitude westerly winds.westerly winds.

B. Local Winds / B. Local Winds / BreezesBreezes

1. Sea Breeze1. Sea Breeze – in the – in the daytimedaytime, , winds from cooler water replace winds from cooler water replace warm rising land airwarm rising land air

2. Land Breeze2. Land Breeze – at – at nightnight, winds , winds from cooler land replace warm from cooler land replace warm air over the waterair over the water

3. Valley Breeze3. Valley Breeze – in the day – in the day warm air rises UP the valleywarm air rises UP the valley

4. Mountain Breeze4. Mountain Breeze – at night, – at night, cool air sinks DOWN the cool air sinks DOWN the mountainmountain

What causes weather?What causes weather?

•uneven heating by the uneven heating by the Sun due to Earth’s axis Sun due to Earth’s axis tilt tilt

•energy transfer energy transfer between Earth’s surface between Earth’s surface and the atmosphereand the atmosphere