Chapter Chapter 1515The The

AtmospherAtmospheree

You breathe out of which layer?

The air we breathe and The air we breathe and all the weather we see all the weather we see is contained in the is contained in the lowest 1% of the lowest 1% of the Earth’s atmosphere.Earth’s atmosphere.

The air we breathe and The air we breathe and all the weather we see all the weather we see is contained in the is contained in the lowest 1% of the lowest 1% of the Earth’s atmosphere.Earth’s atmosphere.

Take a deep breath

What is air made out of?What is air made out of?

Is air strong? Is it matter?Is air strong? Is it matter?

Why is our atmosphere Why is our atmosphere important? Why doesn’t it float important? Why doesn’t it float

awayaway

Chapter 15 Big IdeaChapter 15 Big Idea

Our atmosphere is Our atmosphere is critical to all life on critical to all life on Earth. Human actions Earth. Human actions have a great impact on have a great impact on our atmosphere.our atmosphere.

Section: Earth’s AtmosphereSection: Earth’s Atmosphere Describe the properties of the Describe the properties of the

atmosphere.atmosphere. Identify the main layers of the Identify the main layers of the

atmosphere.atmosphere. Explain how heat is transferred Explain how heat is transferred

in the atmospherein the atmosphere

What is the Atmosphere?What is the Atmosphere?

The The atmosphere atmosphere is a thin is a thin layer of layer of gases gases surroundinsurrounding our g our planetplanet

Why is the ATMOSPHERE Why is the ATMOSPHERE important?important?

Earth’s atmosphere makes life on Earth possible.

1. Protects us from sun’s rays.2. Provides vital gases like

oxygen, nitrogen and carbon dioxide.

3. Keeps temperature comfortable

4. Allows water to circulate around planet.

5. Protects us from meteoroids.

The Air Around YouWeatherWeather

Weather is the state of the atmosphere at any one moment.

What is it made of?What is it made of?

Earth’s Atmosphere Earth’s Atmosphere is made of:is made of:

1.1. 78 % Nitrogen78 % Nitrogen

2.2. 21% Oxygen21% Oxygen

3.3. 1% a bunch of 1% a bunch of others (Argon, others (Argon, Carbon Dioxide, Carbon Dioxide, Water Vapor…)Water Vapor…)

Water in the AirWater in the Air

Relative HumidityRelative HumidityAmount of water vapor in the airChanges constantlyWarm Air = More MoistureCondensation = Clouds

Air PressureAir Pressure

The force of a The force of a column of air column of air pushing down pushing down on an areaon an area

Where is air Where is air pressure greater, pressure greater, sea level or top of sea level or top of a mountain?a mountain?

As altitude increases air pressure decreases…quickly

BarometersBarometers

An An instrument instrument used to used to measure measure air air pressure.pressure.

Changing air pressure is a great indicator of weather changes.

Air pressureAir pressure

Differences in air Differences in air pressure is going pressure is going to help us to help us understand:understand:

1.1. WindWind

2.2. Cloud formationCloud formation

3.3. TornadoesTornadoes

4.4. Almost all Almost all weatherweather

Four Main Layers of Four Main Layers of AtmosphereAtmosphere

The four main layers The four main layers of our atmosphere of our atmosphere are classified are classified according to according to changes in changes in temperature.temperature.

TroposphereTroposphere StratosphereStratosphere MesosphereMesosphere ThermosphereThermosphere

The TroposphereThe Troposphere

The Troposphere:The Troposphere: Inner most layerInner most layer

(0 to 12km)(0 to 12km) Where all Where all

weather occursweather occurs The temperature The temperature

decreases decreases to -60 to -60 degrees at top.degrees at top.

The TroposphereThe Troposphere

Clouds, rain, Clouds, rain, snow and all snow and all precipitation precipitation occur here.occur here.

Air Pressure and Air Pressure and Temperature Temperature drop quickly in drop quickly in troposphere.troposphere.

StratosphereStratosphereLayer above Layer above

troposphere where troposphere where atmosphere atmosphere warms slightlywarms slightly

Ozone layer located Ozone layer located there blocks out there blocks out harmful UV Raysharmful UV Rays

MesosphereMesosphere ““Middle Layer”Middle Layer”

Temperatures Temperatures reach -90 degrees reach -90 degrees CelsiusCelsius

Where Where meteoroids burn meteoroids burn up in up in atmosphereatmosphere

ThermosphereThermosphere “Thermo” means heat Air is only 0.0001 % as

dense as sea level Air slowly blends into

outer space Hottest layer of

atmosphere because energy from the sun strikes it first

Heat Transfer in the Heat Transfer in the TroposphereTroposphere

1) Radiation: The transfer of energy through space, such as heat from the sun to Earth’s atmosphere

2) Conduction: The transfer of heat directly between two objects that are in contact

Heat Transfer in the Heat Transfer in the TroposphereTroposphere

3) Convection: The transfer of heat by the movement of currents within a fluid (liquid or gas)

Heat Transfer in the Heat Transfer in the TroposphereTroposphere

Air Masses And Fronts

The Air Outside Today, Was Somewhere Else Yesterday

What IS An Air Mass?What IS An Air Mass?An Air Mass is a An Air Mass is a

huge body of huge body of air with similar air with similar temperature, temperature, humidity and humidity and pressure.pressure.

They sometimes They sometimes spread over spread over hundreds of square hundreds of square miles. miles.

Types of Air MassesThere are 4 main There are 4 main

types of air types of air masses:masses:

1) Polar1) Polar

2) Tropical2) Tropical

3) Maritime3) Maritime

4) Continental4) Continental

Each has unique Each has unique weather weather associated with it.associated with it.

4 Major Air Masses of 4 Major Air Masses of North AmericaNorth America

1. Maritime Tropical: Warm, Moist Air2. Maritime Polar: Cold, Moist Air3. Continental Tropical: Warm, Dry

Air4. Continental Polar: Cold, Dry Air

Where do they originate?

What Are Fronts?Fronts are areas Fronts are areas

where 2 or where 2 or more air more air masses collide. masses collide.

Air with different Air with different temperature, temperature, humidity and humidity and pressure DO pressure DO NOT MIX WELL.NOT MIX WELL.

Types of FrontsThere are four

types of front:1) Cold Front2) Warm Front3) Stationary

Front4) Occluded

Front

Cold FrontsCold Fronts occur Cold Fronts occur

where cold air where cold air runs into slowly runs into slowly moving warm air.moving warm air.

Cold air being Cold air being more dense more dense pushes warm air pushes warm air up. Warm moist up. Warm moist rising air can rising air can cause clouds and cause clouds and storms.storms.

Cold FrontsCold Fronts

Warm FrontsWarm FrontsWarm Fronts

occur where a warm air mass collides with a slower moving cold air mass.

Because warm air is less dense, it rides above the cold air.

Warm FrontsWarm Fronts

move more slowly than cold fronts so weather changes occur more slowly.

In winter they often bring snow.

Warm FrontsWarm Fronts

Section: Pollution of The Section: Pollution of The AtmosphereAtmosphere

What are the main sources of air pollution?

Describe how smog forms Explain what a temperature inversion is

and how it can make are pollution worse.

TERMS: primary and secondary air pollution, catalytic converter, ZEVs, smog, temperature inversion

What Causes Air Pollution?

Air pollution is Air pollution is harmful harmful substances in the substances in the airair

To plants, animals To plants, animals and other organismsand other organisms

Impact ecosystem Impact ecosystem functionsfunctions

WHAT SHOULD BE IN WHAT SHOULD BE IN THE AIR?THE AIR?

Some Natural Most Human Made

Can you think of other human made AND natural sources of air pollution?

Primary vs. Secondary

Primary pollutant: put directly in the air

(soot from smoke)

Secondary forms when primary pollutant react with other pollutants

(Smog)

Primary vs. Secondary

Primary vs. Secondary

Sources of Air PollutionMain Sources of Air

Pollution Burning fossil fuels

in cars and at power plants (coal, oil and natural gas)

Urban areas vehicles and industry

Mobile vs. Stationary Sources

What can you learn from this graph?

Human Made vs. Natural

History of Air Pollution Not a new problem Why do you think world air-quality

today is a bigger problem?

History of Air Pollution Not a “new” problem,

but scale has changed during industrial revol.

London “smog” killed 2,000 in 1880, 1,000 in 1911 and between 4,000 and 12,000 in 1952

1948 Donora PA 6,000 sick

1963 NYC 300 killed

Today’s U.S. Air Quality

http://airnow.gov/U.S. Government Web Site With Up To Minute Air Quality

Data From Monitors Across the country

http://www.epa.gov/air/data/geosel.html

U.S. EPA Air Quality Data: Tons of data regarding air quality across the U.S.

http://www.epa.gov/airtrends/EPA report on air trends in U.S.

Smog(Smoky – Fog) Smog(Smoky – Fog) Smog Secondary Pollutant Secondary Pollutant

in many urban areasin many urban areas Forms from Forms from

chemical reaction chemical reaction Vehicle exhaustVehicle exhaust Needs sunlight and Needs sunlight and

warm temperatureswarm temperatures OZONEOZONE

Smog

Huge Problem in cities …WHY?

Smog Levels Are Influenced By:Local climateTopographyPopulation DensityAmount of industryTransportation

Smog: Why care?Smog Impacts:Breathing ProblemsCoughing, Eye IrritationAggravates asthma, heart problemsSpeeds up aging of lung tissueDamage plantsReduce Visibility

Smog and Temperature Inversion

Normally as you go up in the troposphere what happens to temperature?

Temperature Inversion occurs when a warmer layer forms above a cooler layer

Traps air near ground

Temperature Inversion

Helena Montana

Clean Air Act

U.S. Law Passed Congress in 1963 and strengthened 1990Has been huge success

Since the Clean Air Act Since the Clean Air Act was first enacted in was first enacted in 1963, emissions of the 1963, emissions of the worst pollutants in the worst pollutants in the U.S. have decreased U.S. have decreased by 57%.by 57%.

Since the Clean Air Act Since the Clean Air Act was first enacted in was first enacted in 1963, emissions of the 1963, emissions of the worst pollutants in the worst pollutants in the U.S. have decreased U.S. have decreased by 57%.by 57%.

Clean Air Act

Cars today are about 95% cleaner running

Zero-Emission Vehicles (ZEV)

Have no tailpipe emissions

Chevy Volt 2010: will travel 30 miles on a battery before gas engine kicks in

Nissan Leaf travels about 100 miles before needing to be charged again

http://www.youtube.com/watch?v=f48x9baSuF0

Clean Air Act

Requires industries to clean up smokestack emissionsRequires Scrubbers

Scrubbers

Section Review

What are the main sources of air pollution?

Describe how smog forms Explain what a temperature

inversion is and how it can make are pollution worse.

TERMS: primary and secondary air pollution, catalytic converter, ZEVs, smog, temperature inversion

What will be the future?