Energy Transfer from Sun

Energy Transfer from SunEnergy Transfer from Sun

Electromagnetic energyElectromagnetic energy is a is a type of energy that is type of energy that is radiated by the sun in the radiated by the sun in the form of transverse waves form of transverse waves vibrating at right angles to vibrating at right angles to the direction of movementthe direction of movement

Radiation occurs in different forms identified by their wavelengths

WHAT HAPPENS TO ELECTROMAGNETIC ENERGY (RADIATION) ONCE IT REACHES EARTH?

Radiation is reflected – bounced back at the same angle they arrived

Radiation is scattered – reflected in various directions

Radiation is refracted - bent

Radiation is transmitted – pass through the material

Radiation is absorbed (taken in as heat energy)

Radiation Radiation

ConductionConduction

ConvectionConvection

Once energy is absorbed within the Once energy is absorbed within the Earth-Atmosphere systemEarth-Atmosphere system HEAT can be transported be 3 HEAT can be transported be 3 methodsmethods

Radiant Energy examples:

1. Sun warms face

2. Apparent heat of the fire

CONDUCTION – MOLECULES TRANSFER CONDUCTION – MOLECULES TRANSFER KINETIC ENERGY (KE) THROUGH KINETIC ENERGY (KE) THROUGH VIBRATIONS OR COLLISIONSVIBRATIONS OR COLLISIONS

SOLIDS BEST FOR CONDUCTION

MOLECULES CLOSE TOGETHER

CONVECTION OCCURS IN THE ATMOSPHERE

CONDUCTION HEATS ONLY THE LOWEST ATMOSPHERE TOUCHING EARTH’S SURFACE (UP TO ABOUT 6 FT.) CONVECTION CAUSES AIR TO RISE DUE TO DENSITY DIFFERENCES

EARTH ABSORBS SHORTWAVE RADIATIONEARTH ABSORBS SHORTWAVE RADIATION

EARTH EMITS LONGWAVE RADIATIONEARTH EMITS LONGWAVE RADIATION – – TERRESRIAL INFRARED RADIATIONTERRESRIAL INFRARED RADIATION

TROPOSPHERE IS MAINLY HEATED BY TROPOSPHERE IS MAINLY HEATED BY RERADIATED TERRESTRIAL INFRARED RERADIATED TERRESTRIAL INFRARED RADIATION FROM EARTH RADIATION FROM EARTH

“ “GREENHOUSE GREENHOUSE EFFECT”EFFECT”

GREENHOUSE GASESGREENHOUSE GASES

CARBON DIOXIDE AND METHANE

THE BURNING OF FOSSIL FUELS

Life on Earth due to Greenhouse Life on Earth due to Greenhouse EffectEffect

Earth is the “Goldilocks Planet” – just right – Earth is the “Goldilocks Planet” – just right – average temperature is 59average temperature is 59°° F (w/o GE our average F (w/o GE our average temperature would be -3temperature would be -3° F)° F)

Mars’ average temperature is -67° F (1/5 of our Mars’ average temperature is -67° F (1/5 of our atmosphere)atmosphere)

Venus’ average temperature due to GE is Venus’ average temperature due to GE is 855855° F ° F

Mercury’s temperature 333° FMercury’s temperature 333° F

RADIATION BALANCERADIATION BALANCE

DYNAMIC EQUILIBRIUMDYNAMIC EQUILIBRIUM

INPUT = OUTPUTINPUT = OUTPUT

Is global warming changing the balance???????

¾ OF THE ENERGY ABSORBED BY ¾ OF THE ENERGY ABSORBED BY EARTH EVAPORATES WATER FROM EARTH EVAPORATES WATER FROM

THE OCEANSTHE OCEANSEVAPORATION EVAPORATION 540 CALORIES/GRAM GAINED540 CALORIES/GRAM GAINEDThe gram of water absorbed 540 calories of latent The gram of water absorbed 540 calories of latent heat as it changed to vapor (heat as it changed to vapor (require addition of energyrequire addition of energy)) COOLING EFFECTCOOLING EFFECT

CONDENSATIONCONDENSATION 540 CALORIES/GRAM RELEASED540 CALORIES/GRAM RELEASEDThe gram of water released 540 calories of latent The gram of water released 540 calories of latent heat as it changed to liquid (heat as it changed to liquid (give off energygive off energy)) WARMING EFFECTWARMING EFFECT