Heat Transfer How heat gets from one place to another

Temperature & Heat Heat and temperature are used interchangeably but have different meanings in Earth Science Heat and temperature are used interchangeably but have different meanings in Earth Science –Temperature: is the average amount of energy in each molecule of a substance –Heat: is energy transferred from one object to another The faster atoms in air move the higher the temperature The faster atoms in air move the higher the temperature

Energy Transfer There are three ways energy is transferred There are three ways energy is transferred –Radiation –Convection –Conduction All three are used in transferring energy on the surface of the earth All three are used in transferring energy on the surface of the earth

Conduction Conduction is the transfer of heat through matter by molecular activity. Conduction is the transfer of heat through matter by molecular activity. –The concept of conduction says that something in contact with a hot substance will become hot also (heat works its way through the material)  This is best seen in solids  Impossible in Vacuums –Example: a spoon left in a hot soup, the spoon handle becomes hot

Conduction Not all substances conduct heat in the same way Not all substances conduct heat in the same way –Metals transfer heat through conduction very easily –Air is not a good conductor of heat due to it’s low density Conduction only occurs between the surface and air directly in contact with it Conduction only occurs between the surface and air directly in contact with it Conduction is the least significant transfer of heat for the atmosphere Conduction is the least significant transfer of heat for the atmosphere

Convection Convection is the transfer of heat through mass movements or circulations within a substance Convection is the transfer of heat through mass movements or circulations within a substance –The concept of Convection works by pockets of material circulating within itself  Best seen in Gasses and Liquids  Impossible in Vacuums & Solids –The heater in your car is the best example

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Convection Convection will only occur if heating of a fluid substance is uneven Convection will only occur if heating of a fluid substance is uneven Convection in the atmosphere occurs because the atmosphere is heated unevenly Convection in the atmosphere occurs because the atmosphere is heated unevenly –Hot air and liquids rise –Cold air and liquids sink

Radiation Radiation is the emission of energy in all directions in the form of light (visible and non visible) Radiation is the emission of energy in all directions in the form of light (visible and non visible) –Radiation works from the concept that when things become hot they emit energy in the form of light –Works best in vacuums –Solids, liquids & gases absorb & reflect radiation causing to not be as affective

Radiation There are 4 basic laws that affect radiation There are 4 basic laws that affect radiation –All objects with any temperature emit radiation –Hotter objects emit more radiation then cold –Objects that are good absorbers are also good emitters of radiation –Hotter objects emit higher energy maximums*

Radiation The largest source of radiation for the Earth is the Sun The largest source of radiation for the Earth is the Sun –The earth emits its own radiation but not in the same way or amount Radiation from the sun interacting with the atmosphere produces the blue colored sky Radiation from the sun interacting with the atmosphere produces the blue colored sky