The Atmosphere

Atmosphere Made up of mostly nitrogen and oxygen Protects us from the Sun “atmo” means air/vapor Also contains dust, volcanic ash, sea salt, dirt, smoke, and other pollutants

Air Pressure Force of all the air pushing down Decreases with altitude (height)

Temperature Composition of the atmosphere effects temperature Temperatures drop, raise, drop, and raise again the higher up you go (each layer acts differently)

Troposphere most dense and most pressure Closest to Earth’s surface Is where the weather happens Has clouds, water vapor, pollution Gases mix due to varying temp’s “tropo” means turn/change

Stratosphere Gases here are layered and do not mix Air is thin with little moisture Ozone layer is here - absorbs the ultraviolet radiation from the sun (making life on earth possible) “strato” means layered

Mesosphere “Meso” means middle Coldest layer

Thermosphere Uppermost layer High temp’s but feels cold Mostly made of O+, N+, and He+ ions

Conduction the transfer of heat through direct contact occurs when hot air molecules contacts Earth’s surface Example: touching hot item

Convection transfer of heat in currents of a liquid or a gas hot liquids and gases move up, cool move down Examples: heat rising off hot street, boiling water

Radiation transfer of heat through invisible waves Comes from the Sun or something hot Responsible for the weather cycle Example: face is warmed with sunlight on it

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Greenhouse Effect The warming of Earth because the atmosphere holds heat like a blanket; (carbon dioxide and water vapor hold heat)

Global Warming increase in global temperature due to an increase in greenhouse gases (carbon dioxide)