Chapter 6 Earth’s Atmosphere

Importance of the Atmosphere Atmosphere: thin layer of air that forms a protective covering around the planet Balances heat absorbed (from sun) and heat released (into space) Protects us from sun’s harmful rays

What is the atmosphere made up of? Mixture of gases, liquids and solids Extends from earth’s surface to outer space Gases in the atmosphere 78% : Nitrogen 21% : Oxygen 1% : other gases 0.93%: Argon 0.03%: Carbon Dioxide Vapor, ozone, helium, methane, krypton, xenon

Atmosphere continued Solids in the atmosphere: dust, salt, pollen Liquids in the atmosphere Small liquid droplets from clouds, volcanic eruptions Mount Pinatubo--- Phillipines

Layers of the atmosphere

Layers of the Atmosphere 5 layers, each with own unique properties Lower layers Troposphere Stratosphere Upper layers Mesosphere, Thermosphere Exosphere

Troposphere Lowest layer Extends up to 10 km Temperature decreases as you go up Where all weather occurs Most of total mass of atmosphere is located here (ocean, mountains, people, animals, plants etc)

Stratosphere Layer above troposphere 10-50km Temperature increases as you go up Contains Ozone (O3) Ozone (O3) : gas that absorbs sun’s harmful rays (solar radiation)

Mesosphere Layer above stratosphere 50-85km Temperature decreases as you go up Find meteors here Most meteors that enter the atmosphere burn up here

Thermosphere Layer above the mesosphere 85km-500km Temperature increases as you go up (heated by radiation from the sun) Thickest layer, known for its high temperatures Air is very thin (molecules very spread apart) Contains layer-ionosphere (radio waves) and exosphere

Exosphere Highest layer of the atmosphere (before space) 500 km-1,000km, upper boundary 10,000 km (6,200 miles) Very thin air (molecules extremely far apart) Satellites Space shuttle orbits

Glossary Words Atmosphere Troposphere Stratosphere Mesosphere Thermosphere Exosphere Ionosphere Water cycle

Energy Transfer in the Atmosphere Light energy VS Heat Energy

Energy from the Sun Sun provides most energy on Earth Drives ocean and wind currents Allows plants to grow and produce food provides nutrition to animals Sun’s energy can be… - reflected back into space by clouds, atmosphere and Earth’s surface (35%) - Absorbed by the atmosphere or Earth’s surface (65%)

Heat Heat- flow from high temperature to low temperature 1) Energy from the sun reaches Earth’s surface 2) Heat transferred by radiation, conduction, convection (distributes the Sun’s heat throughout the atmosphere)

Radiation Energy transferred in the form of rays or waves Sun reaches Earth in the form of radiant energy Feel the Sun’s heat and warmth

Conduction Transfer of energy that occurs when molecules bump into one another (direct contact) Earth’s surface conducts energy directly to the atmosphere - As air moves over warm land or water, molecules in air are heated by conduction

Convection Transfer of heat by the flow of material Circulates heat throughout the atmosphere Cool air sinks, Warm air rises Convection current

The Water Cycle Hydrosphere: describes all water on Earth Constant cycling of water within the atmosphere and hydrosphere- determines weather patterns and climate types Water moves from Earth Atmosphere Earth Evaporation Condensation Precipitation

The Water Cycle 1) Sun- liquid (lakes, streams, oceans) gas (EVAPORATION) 2) Water vapor cools changes back to a liquid- clouds form (CONDENSATION) 3) Clouds grow in droplet size and fall to Earth (PRECIPITATION) 4) RUNOFF precipitation to groundwater back to ocean

Questions from Water Cycle Model and Study Cards What do you see happening? What did the ice do to the water that went into the air? What happened to the water in the air after it cooled? Where did the drops of water (rain) go? How was the water in our model heated? What heats water in the real oceans and lakes? What did our lamp represent?

Atmospheric Pressure Pressure= Force/Area (force exerted on a surface divided by the total area over which the force is exerted) Atmospheric Pressure Air (makes up the atmosphere around Earth) around you presses on you with tremendous force

Variations in Atmospheric Pressure Atmospheric pressure changes with altitude As altitude increases- pressure decreases Fewer air particles are found in a given volume As altitude decreases  pressure increases More air particles are found in a given volume

Fluids in her body exert a pressure that BALANCES atmospheric pressure Balanced Pressure Why don’t we feel air pressure? Pressure exerted outward by fluids of your body balances the pressure exerted by the atmosphere on the surface of your body Fluids in her body exert a pressure that BALANCES atmospheric pressure

Pascal Experiment with a balloon (pg 120) Designed an experiment in which he filled a balloon only partially with air. He then had the balloon carried to the top of a mountain. As he predicted, the balloon expanded while being carried up the mountain. The amount of air inside the balloon stayed the same, while the air pressure pushing in on it from the outside decreased. The particles of air inside the balloon were able to spread out further

Air movement Uneven heating of Earth’s surface causes some areas to be warmer than others. Due to Earth’s curve Equator receives more radiation (direct) than North or South poles

Heated Air Convection currents Equator: hotter air from suns radiation—less dense (rise)---LOW PRESSURE Poles: colder air---more dense (sink)---HIGH PRESSURE

The Coriolis Effect Rotation of the Earth causes moving air and water to appear to turn to the RIGHT north of the equator (northern hemisphere) LEFT south of the equator (southern hemisphere) Coriolis Effect + uneven heating of Earths surface  Distinct wind patterns which influence weather

Global Winds Doldrums : Trade Winds: Westerlies: Easterlies: near the equator (low pressure area) Windless, rainy zone Trade Winds: air extending to 30°N & S steady winds Westerlies: 30 °– 60° N&S moves opposite trade wind, responsible for much movement of weather in N. Hemisphere Easterlies: Found near the poles north pole-move southwest, south pole- northwest

Jet Streams Narrow belts of strong winds that blow near the top of the troposphere (~8mi high) The polar jet stream forms at the boundary of cold, dry polar air to the north and warmer, more moist air to the south.

Local Wind Systems SEA BREEZE LAND BREEZE Smaller wind systems affect local weather Sea and Land Breezes Convection currents over areas where land meets the seawinds SEA BREEZE LAND BREEZE During the day (solar radiation warms the land more than water) During the night, (land cools more rapidly than water) Warm air rises over land, Cool air sinks and moves from water towards land Warm air rises over water, cool air sinks and moves from land toward the water

Sea Breeze (Day)

Land Breeze (Night)

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