GEOG 303

Heat

Sensible heat is a measure of kinetic energy of molecules.

Radiation

The flow of electromagnetic energy that travels in waves.

Wavelength Spectra

Includes visible light, X-ray, UV light, Gamma rays, Infrared, Microwaves, and Radio.

Electromagnetic Radiation (EMR)

Energy that can be transferred, similar to ocean waves.

Wavelength and Frequency

Wavelength is inversely related to frequency; small waves have high frequency.

Planck’s Law

Energy at a specific wavelength is dependent on temperature.

Black Body

An object that absorbs all radiation and emits maximum radiation for its temperature.

Stefan-Boltzmann Law

There is a direct relationship between an object's temperature and the radiation it emits.

Emissivity

A coefficient that identifies the proportion of radiation received that is emitted.

Wien’s Law

The wavelength at which maximum energy emission occurs is 2897 µm K.

Shortwave Radiation

Originates from the sun and includes Gamma rays, X-rays, UV radiation, and visible light.

Longwave Radiation

Originates from the Earth as thermal infrared (heat).

Absorption

Energy is transferred to the material.

Reflection

Energy bounces off and back out of the material.

Transmission

Energy passes through the material.

Conservation of Energy

The sum of absorbed, reflected, and transmitted energy equals 1.

Scattering

Depends on wavelengths of EMR, particle size, and distance traveled through the atmosphere.

Rayleigh Scattering

Shorter wavelengths are scattered by smaller particles, causing the sky to appear blue.

Mie Scattering

Occurs when EMR wavelength is similar to particle size, influenced by aerosols.

Non-selective Scattering

Larger particles scatter EMR, leading to cloudy or dark days.

Diffuse Radiation

Radiation that can be direct or diffuse due to scattering.

Greenhouse Effect

Trapping of Earth's surface heat by the atmosphere, allowing visible light to pass through while absorbing infrared radiation.

Greenhouse Gases

Include water vapor, carbon dioxide, methane, ozone, and nitrous oxide.

Methane Emissions

Methane's direct effect is about 60 times stronger than carbon dioxide over 20 years.

Forcing

An external or internal driver causing climate change.

Feedback

A response to climate forcing that amplifies or buffers the initial change.

Water Vapor

Short residence time in the atmosphere; acts as a feedback.

Local Energy Balances

Energy from solar radiation is converted to thermal or latent heat.

Kinetic Energy

Energy of movement, calculated as E = ½ m • v².

Potential Energy

Energy associated with gravity or chemistry, calculated as E = mgh.

Internal Energy

Total energy within a system.

Heat Transfer

The transfer of energy from one object to another, occurring through conduction and convection.

Conduction

Energy transfer through direct contact, occurring in the laminar layer.

Convection

Energy transfer due to fluid movement, occurring more rapidly with greater temperature differences.

Sensible Heat

Energy transfer measurable with a thermometer.

Specific Heat

The amount of heat required to raise the temperature of 1 kg of a substance by 1 K.

Latent Heat

Heat associated with a phase change, not measurable with a thermometer.

Inverse Square Law

An object twice the distance from a light source receives a quarter of the illumination.

Angle of the Sun

Determines the seasonality of a region; equatorial regions receive more direct sunlight.