A mixture of gases that surround a planet or moon

1. oxygen we need to breathe
2. protects from the sun's rays

what makes up the atmosphere?

1. nitrogen 78%
2. oxygen 21%
3. carbon dioxide + other gases 1%

altitude increases=air pressure decrease

1. strongest at earth's surface
2. wind + weather move high to low pressure
3. air has mass

tool used to measure air pressure

1. low air pressure=mercury in colum drops
2. high air pressure=mercury in colum increases

1. thermosphere
2. mesosphere
3. stratosphere

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4. troposphere

edge of atmosphere (end layer)

1. high temperatures without feeling hot
2. particles are excited from the sun's rays but do not bounce off eachother and give off heat

the middle layer

1. coldest layer

Home of the ozone layer

1. air is very thin
2. contained by the ozone layer
3. ozone layer- protects life on earth by absorbing harmful UV radiation

Layer where we live

1. Lowest layer (next to earth's surface)
2. most dense layer
3. temperature decreases as altitude increases

ionosphere

Home of the Auroras

1. ions- electrically charged particles
2. gas particles of the thermosphere become electrically charged and radiate energy as shimmering lights called auroras

radiation,conduction, and convection

1. radiation- energy transfered by waves
2. conduction- radiation transfered by contact
3. convection- energy transfered by circulation

transfer of electromagnetic waves

1. electromagnetic waves- are streams of light energy that travel in wave patterns
2. earth recieves radiation energy from the sun

transfer of heat energy through a material

1. heat energy foes from warm to cold areas
2. air molecules come into direct contact with the warm earth and heat energy is transfered to the atmosphere

the transfer of thermal energy by the circulation of a liquid or gas

1. as air is heated it becomes less dense and rises
2. cold air is more dense so it sinks
3. convection current- circular movement of air caused by the cycle of warm air rising and cold air sinking
4. as cold air sinks it pushes warm air up

the process by which gases in the atmosphere such as water vapor and carbon dioxide absorb thermal heat energy and radiate back to earth

1. gases act like glass wall for a green house that allow sunlight to enter but stop heat from escaping
2. 70% of radiation that enters earth's atmosphere is absorbed by the clouds and earth's surface

Average temp. of earth has increased in past 100 years

1. green house gases- absorb heat and energy in atmosphere
2. example- carbon dioxide, methane, Nitrous oxide
3. human activity such as fossil fuels and deforestation increase these gases
4. the rise in global temperature changes climate patterns and how plants and animals survive

the movement of air caused by differences in air pressure

1. remember- air moves from high to low pressure
2. the greater the air pressure the faster the wind moves
3. air circulates because temperature differences in wind cause pressure differences in atmosphere
4. air moves between the poles and the equator because of the pressure and temp. difference