GEO MID term - Energy Transfer and Solar Radiation

Absorption

Some objects absorb electromagnetic waves

Different materials have different absorptive capabilities

An object that is a good radiator is also a good absorber, and vice versa

Mineral materials are generally good absorbers

Snow and ice are poor absorbers (Water surfaces vary)

Dark-colored surfaces are much more efficient absorbers of radiation

than light-colored surfaces

Adiabatic Heating and Cooling

No net heat transfer

Increasing pressure adiabatically

heats air masses

Falling pressures allow air to

expand and cool

Heat Transfer Modes

Conduction - process of heat

transfer from molecule to

molecule (requires contact)

Convection - movement of a fluid

in response to heat

Advection - movement of material

dissolved or suspended in the

fluid

Reflection

Ability of an object to repel electromagnetic waves that strike it

Insolation is deflected back to space at the same angle and initial

wavelength with which it arrived

A good absorber is a poor reflector

Albedo - overall reflectivity of an object or surface; higher albedos

reflect more radiation

Shortwave versus Longwave Radiation

Shortwave radiation is of solar

origin

Longwave radiation is of terrestrial

(Earth) origin

Earth’s radiation budget -

relationship between shortwave

and longwave radiation

Transmission

Solar radiation passing through a

medium (surface or object)

Mediums vary considerably in

their capacity to transmit

electromagnetic waves

The transmission ability of a

medium generally depends on the

wavelength of radiation

Visible Light

Wavelengths between 0.4 and 0.7

micrometers

Approximately 47 percent of total

solar energy arrives at Earth as visible light