Chapter 4 Atmospheric Energy and Global Temperatures

Vocabulary flashcards covering key concepts from the lecture notes on Atmospheric Energy and Global Temperatures.

Energy Balance

The global energy budget of the Earth–atmosphere system with inputs (shortwave solar radiation) and outputs (longwave infrared radiation), typically in a steady state with local variations.

Shortwave Radiation

Ultraviolet, visible, and near-infrared solar radiation that enters the Earth–atmosphere system.

Longwave Radiation

Thermal infrared radiation emitted by Earth and its atmosphere; energy leaving the system.

Scattering

Change in the direction of light due to interactions with particles, producing diffuse radiation.

Rayleigh Scattering

Scattering by small molecules (O2, N2) that preferentially scatters shorter wavelengths (blue/violet).

Mie Scattering

Scattering by larger particles (smoke, dust) that tends to scatter longer wavelengths.

Refraction

Bending of light as it passes between media of different optical density, changing speed and direction.

Albedo

Reflective quality of a surface (percentage of light reflected); Earth’s albedo is about 31%.

Insolation

Incoming solar radiation reaching Earth, the energy input to the system.

Potential Energy

Energy of position or composition (e.g., reservoir above a dam or petroleum).

Kinetic Energy

Energy of motion (e.g., walking; molecular vibrations; temperature is a measure of vibration).

Temperature

A measure of the average kinetic energy (molecular vibration) of a substance.

Heat

Transfer of kinetic energy between bodies due to a temperature difference; flows from higher to lower temperature.

Sensible Heat

Heat that you can feel; temperature changes; transferred by conduction and convection.

Latent Heat

Heat due to a change in state (melting, evaporation, sublimation) without a temperature change; released during freezing, condensation, deposition.

Radiation

Energy transfer by electromagnetic waves.

Conduction

Heat transfer through direct molecular contact from hotter to cooler objects.

Convection

Heat transfer by vertical mixing and circulation within a fluid.

Advection

Horizontal transport of atmospheric properties by wind.

Greenhouse Effect

Atmospheric warming where greenhouse gases absorb outgoing longwave radiation and re-radiate it back to Earth, delaying heat loss.

Real Greenhouse

A physical greenhouse that traps warm air; differs from the atmospheric greenhouse effect.

Clouds

Affects atmospheric temperature by cooling or heating depending on cover, type, altitude, and thickness.

Aerosols

Particles in the atmosphere that can cool by reflection (e.g., sulfur dioxide) or warm by absorption (e.g., black carbon).

Incoming Solar Radiation Budget

Distribution of solar energy: ~31% reflected, ~24% absorbed in the atmosphere, ~45% absorbed at the surface.

Outgoing Longwave Radiation Budget

Longwave energy emitted to space and absorbed/re-radiated by greenhouse gases, clouds, and dust back toward Earth.

Net Radiation Budget

Balance between absorbed shortwave radiation and emitted longwave radiation, plus nonradiative fluxes (latent heat, sensible heat, ground heat flux).

Nonradiative Fluxes

Latent heat (evaporation/condensation), sensible heat (conduction/convection), and ground heat flux (G).

Ground Heat Flux (G)

Heat transfer into or out of the ground by conduction (and some advection).

Urban Heat Island

Urban areas become warmer than surrounding rural areas due to land-use changes and heat-absorbing surfaces.

Latitudinal Energy Balance

Concept that tropical regions have surplus energy while polar regions have deficit, leading to a global balance (often near 36°N/S).

Absorption

Process by which radiant energy is taken up by a surface or medium.