Atmosphere

Composition of the Earth’s Atmosphere The The atmosphere is a mixture of gases is a mixture of gases

with some suspended solids and with some suspended solids and liquids.liquids.

Nitrogen is the most common gas at is the most common gas at 78% of the atmosphere.78% of the atmosphere.

Oxygen is the next most common gas is the next most common gas at 21%at 21%

Composition of the Atmosphere

Earth’s Atmosphere

Trace amounts of other gases are of other gases are found that total only found that total only 1 %: water vapor, water vapor, Carbon Dioxide, Neon, Carbon Dioxide, Neon, Methane,Ozone, Hydrogen, HeliumMethane,Ozone, Hydrogen, Helium

Other Planets’ Atmospheres

Earth’s Atmosphere

Brown SmogBrown Smog is made from nitrogen is made from nitrogen oxides and hydrocarbons. (L.A. type)oxides and hydrocarbons. (L.A. type)

Gray Smog is from burning coal or oil is from burning coal or oil and contains sulfur oxides.and contains sulfur oxides.

Ozone is a pollutant when it is near the is a pollutant when it is near the ground. It is in most smogs.ground. It is in most smogs.

Structure of the Atmosphere

There are There are fivefive main layers in the main layers in the atmosphereatmosphere..

The lowest layer is the The lowest layer is the Troposphere.. The Stratosphere and Mesosphere are the

next highest layers. The Thermosphere and then the

Exosphere are the highest layers.

Layers of the Atmosphere

Layers of the Atmosphere

A. A. The TroposphereThe Troposphere: : 1.Close to the ground1.Close to the ground 2. Contains 75% of the Earth’s gases.2. Contains 75% of the Earth’s gases. 3. Weather, clouds and smog occur at this 3. Weather, clouds and smog occur at this

level.level. It ends at 10 Km above sea level.It ends at 10 Km above sea level.

Layers of the Atmosphere

Layers Of the Atmosphere

B. The StratosphereB. The Stratosphere The The ozone layerozone layer is within the stratosphere. It is a is within the stratosphere. It is a

thin layer of thin layer of OO33 which absorbs UV radiation. which absorbs UV radiation. C. The MesosphereC. The Mesosphere is the middle layer. is the middle layer. D. The Thermosphere D. The Thermosphere contains the ionosphere.

The ionosphere is a layer of electrically charged particles. Radio waves bounce off of it.

E. The Exosphere E. The Exosphere is the highest level before space.

Atmospheric Pressure

Gases in the atmosphere have mass and Gases in the atmosphere have mass and weight. Gravity pulls on the weight. Gravity pulls on the molecules and causes pressuremolecules and causes pressure..

Pressure is force exerted on an area.Pressure is force exerted on an area. P= F/AP= F/A At sea level there are more molecules of air At sea level there are more molecules of air

above an area, so there is more pressure.above an area, so there is more pressure.

Units for Pressure

The S.I. Unit for pressure is Atmospheres The S.I. Unit for pressure is Atmospheres (Atm)(Atm)

The old unit used on T.V. is inches Hg The old unit used on T.V. is inches Hg

( Which is mercury)( Which is mercury) A metric unit is mm Hg ( millimeters)A metric unit is mm Hg ( millimeters) Another unit used is millibars (mb)Another unit used is millibars (mb)

Temperature in the Atmosphere

NAMENAME HeightHeight

(Km)(Km)

TemperatureTemperature

(Celcius)(Celcius)

ExosphereExosphere 500 Km500 Km 600-1000600-1000

ThermosphereThermosphere 200 - 500200 - 500 0-6000-600

MesosphereMesosphere 50 -15050 -150 -5 to 0-5 to 0

StratosphereStratosphere 10 - 5010 - 50 -60 to -5-60 to -5

TroposphereTroposphere 0 – 10 0 – 10 -60 to 50-60 to 50

The Ozone Layer

20 Km above sea level20 Km above sea level Ozone is 3 atoms of oxygen.Ozone is 3 atoms of oxygen. Located in the Stratosphere.Located in the Stratosphere. Ozone absorbs UV radiation from the sun.Ozone absorbs UV radiation from the sun. ODP’s = Ozone Depleting GasesODP’s = Ozone Depleting Gases CFC’s are ODP’s… ChlorofluorocarbonsCFC’s are ODP’s… Chlorofluorocarbons CFC’s break the ozone down to oxygen moleculesCFC’s break the ozone down to oxygen molecules

Energy from the Sun

Radiation Radiation is the transfer of energy by is the transfer of energy by electromagnetic waves. EM waveselectromagnetic waves. EM waves

30% of the radiation from the sun is 30% of the radiation from the sun is reflectedreflected off of the Earth. off of the Earth.

50% of the radiation is 50% of the radiation is absorbed absorbed by Earth’s by Earth’s surface.surface.

Clouds and the atmosphere Clouds and the atmosphere absorbabsorb 20 % . 20 % .

Energy Transfer in the Atmosphere Conduction Conduction – the transfer of energy when – the transfer of energy when

molecules bump into one another.molecules bump into one another. Air near the heated surface of the Earth is Air near the heated surface of the Earth is

heated by conduction.heated by conduction.

Energy Transfer…

Convection Convection -- the transfer of heat by the flow of materials.

Heated air is less dense and rises, cold air sinks. This flow of air is called a convection currentconvection current.

The Water Cycle

The The HydrosphereHydrosphere = All of the water on the = All of the water on the Earth’s surface.Earth’s surface.

97% of water is salt water, only 3% is fresh.97% of water is salt water, only 3% is fresh. 67% of the fresh water is frozen at the polar 67% of the fresh water is frozen at the polar

ice-caps , which are 2 miles thick in some ice-caps , which are 2 miles thick in some places.places.

The Water Cycle

The Water Cycle

Water Water evaporatesevaporates and becomes a gas. and becomes a gas. The evaporated water rises in the The evaporated water rises in the

atmosphere.atmosphere. As the water rises, it cools.As the water rises, it cools. As the gaseous water cool, it As the gaseous water cool, it condensescondenses to to

form a liquid…clouds.form a liquid…clouds. PrecipitationPrecipitation is next; the water falls as rain, is next; the water falls as rain,

snow, sleet, or hail.snow, sleet, or hail.

Water Cycle

Water is recycled constantly.Water is recycled constantly. Water is purified through the water Water is purified through the water

cycle.cycle.

Movement of Air

Wind Wind is caused by the uneven heating of the is caused by the uneven heating of the Earth’s surface and atmosphere.Earth’s surface and atmosphere.

Areas of Areas of temperature differencetemperature difference create areas create areas of of pressure differencepressure difference..

Wind is the movement of air from areas of Wind is the movement of air from areas of high pressure to areas of low pressure.high pressure to areas of low pressure.

Movement of Air

The Coriolis EffectThe Coriolis Effect = the rotation of the = the rotation of the Earth shifts the wind to the right and north. Earth shifts the wind to the right and north.

The Jet streams = high altitude, strong The Jet streams = high altitude, strong winds. The flow west to east in the U.S.winds. The flow west to east in the U.S.

The Jet stream has a major effect on The Jet stream has a major effect on weather.weather.

Movement of Air

Movement of Air

Sea BreezesSea Breezes – created during the day – created during the day because solar radiation warms the land because solar radiation warms the land more than the water. It comes in from the more than the water. It comes in from the sea.sea.

Movement of Air

Land BreezesLand Breezes – created at night, cold air – created at night, cold air over the land forces up the warmer air over over the land forces up the warmer air over the sea. The wind goes out to sea.the sea. The wind goes out to sea.

Monsoon windsMonsoon winds are seasonal winds that are seasonal winds that occur in tropical areas. ( This creates a wet, occur in tropical areas. ( This creates a wet, very rainy season.)very rainy season.)

Tools of Meteorology

Anemometer Anemometer

BarometerBarometer PsychrometerPsychrometer Rain GaugeRain Gauge

UV MeterUV Meter Weather SatelliteWeather Satellite Weather BalloonWeather Balloon