Earth’s Atmosphere. Composition of Earth’s Atmosphere Atmosphere surrounding Earth is a mixture of solids, liquids, and gases. Nitrogen is the most common.

Earth’s AtmosphereEarth’s Atmosphere

Composition of Earth’s Composition of Earth’s AtmosphereAtmosphere• Atmosphere surrounding Earth is a Atmosphere surrounding Earth is a

mixture of solids, liquids, and gases.mixture of solids, liquids, and gases.• Nitrogen is the most common gas at 78%.Nitrogen is the most common gas at 78%.• Oxygen makes up 21 %Oxygen makes up 21 %• Water vapor can range from 0-4%.Water vapor can range from 0-4%.

– Meaning if water vapor is high then the Meaning if water vapor is high then the percentage of the other gases are slightly percentage of the other gases are slightly lower.lower.

– Dust and ice are two common solids found in Dust and ice are two common solids found in the atmosphere.the atmosphere.

– Common liquids in the atmosphere is water.Common liquids in the atmosphere is water.– Water is the only substance that exists as a Water is the only substance that exists as a

solid, liquid, and gas in Earth’s atmosphere.solid, liquid, and gas in Earth’s atmosphere.

SmogSmog

• Is a mixture of compounds that Is a mixture of compounds that include sulfur, nitrogen, and oxygen.include sulfur, nitrogen, and oxygen.

• The burning of coal, gasoline, and The burning of coal, gasoline, and other fossil fuels will produce sulfur other fossil fuels will produce sulfur and nitrogen.and nitrogen.

• Type of pollution.Type of pollution.• Smoke-like haze that hangs over Smoke-like haze that hangs over

cities and towns. cities and towns.

Structure of the AtmosphereStructure of the Atmosphere

• Five main layer. Five main layer. Each with unique Each with unique characteristics.characteristics.– TroposphereTroposphere– StratosphereStratosphere– MesosphereMesosphere– ThermosphereThermosphere– ExosphereExosphere

TroposphereTroposphere

• Layer we live in.Layer we live in.

• Closest to the groundClosest to the ground

• Contains 75% of all Contains 75% of all atmosphere gases, atmosphere gases, as well as dust, ice, as well as dust, ice, and liquid.and liquid.

• Layer where Layer where weather, clouds, and weather, clouds, and smog occur.smog occur.

StratosphereStratosphere

• Lies above the Lies above the troposphere.troposphere.

• Ozone layer exists.Ozone layer exists.

Other LayersOther Layers

• Beyond the stratosphere are the mesosphere, Beyond the stratosphere are the mesosphere, thermosphere, and exosphere.thermosphere, and exosphere.

• One important layer in the thermosphere is the One important layer in the thermosphere is the ionosphere.ionosphere.

• Ionosphere is a layer of electrically charged Ionosphere is a layer of electrically charged particles.particles.

• They can interfere with radio waves.They can interfere with radio waves.• Exosphere uppermost part of Earth’s Atmosphere.Exosphere uppermost part of Earth’s Atmosphere.• There is NO clear boundary between the There is NO clear boundary between the

atmosphere and space.atmosphere and space.

Atmospheric Pressure and Atmospheric Pressure and TemperatureTemperature• Coldest layer of air is Mesosphere and the Coldest layer of air is Mesosphere and the

warmest layer is the troposphere.warmest layer is the troposphere.• In general, atmospheric pressure is In general, atmospheric pressure is

greatest near Earth’s surface and greatest near Earth’s surface and decreases as you move out toward space.decreases as you move out toward space.

• Atmospheric pressure is caused by atoms Atmospheric pressure is caused by atoms and molecules of gas are pushed together and molecules of gas are pushed together because of weight of the atmosphere because of weight of the atmosphere above them.above them.

• Cold air is more dense than warm air, Cold air is more dense than warm air, therefore, has higher pressure.therefore, has higher pressure.

Ozone LayerOzone Layer

• 30km above your head.30km above your head.• Can’t feel, smell, or Can’t feel, smell, or

observe it.observe it.• Is a shield between you Is a shield between you

and harmful energy and harmful energy coming from the sun.coming from the sun.

• A compound whose A compound whose molecules are composed of molecules are composed of three oxygen atoms three oxygen atoms bonded together.bonded together.

• Located in the Located in the stratosphere.stratosphere.

• Absorbs most of the Absorbs most of the ultraviolet radiation.ultraviolet radiation.

• Ultraviolet radiation comes Ultraviolet radiation comes from the sun and causes from the sun and causes sunburn.sunburn.

• Radiation causes cancer Radiation causes cancer and other health problems.and other health problems.

• Ozone layer is Ozone layer is disappearing, there is a disappearing, there is a large hole over Antarctica large hole over Antarctica and a small hole over the and a small hole over the North Pole.North Pole.

• Chlorofluorocarbon Chlorofluorocarbon molecules destroy ozone molecules destroy ozone molecules.molecules.

• They are found in They are found in refrigerants, aerosol refrigerants, aerosol sprays, and foam products.sprays, and foam products.