2. Atmosphere and weather The sun is our main source of heat. The heat travels to us through space in the form of
radiation. This radiation is absorbed by clouds, atmospheric gases and the Earth's
The
con
cold
surface. Some parts of the Earth receive more of this radiation than others. The main
Wednesday, April 12, 2023 4:27 PM reason for this is the curvature of the Earth. This curvature means that, at higher the
latitudes, the radiation from the sun is spread over a much larger surface area, while the fact
same amount of energy is much more concentrated near the equator. The radiation of a
An energy budget refers to the amount of energy Global scale = macro-scale also travels through a greater depth of atmosphere nearer the poles, in comparison to rad
entering a system, the amount leaving the system Local scale = micro-scale the equator so more radiation is lost to scattering and absorption by gases and particles Ear
and the transfer of energy within the system.
in the atmosphere.
Night-time energy budget No insolation and reflected solar radiation
Higher temperatu
1. Long-wave Earth radiation emits shorter wa
2. Latent heat transfer (condensation)
3. Absorbed energy returned to Earth (sub-surface supply)
4. Sensible heat transfer
Daytime energy budget Blackbody radiation
Assumes a horizontal surface with grass-covered soil
Blackbody radiation
Energy available at the surface = incoming solar radiation - temperature, and th
(reflected solar radiation + surface absorption + sensible heat
transfer + long-wave radiation + latent heat transfers) A perfect black body
[1] Incoming (shortwave) solar radiation/insolation is the main energy input. it and emits, at any
□ Affected by latitude, season and cloud cover (the less cloud cover there is, bodies do not really
1. Incoming (shortwave) solar radiation (insolation)
and/or the higher the cloud, the more radiation reaches the Earth's surface). and the sun) as blac
2. Reflected solar radiation
3. Surface absorption
4. Sensible heat transfer [2] Reflected solar radiation Wien's displacemen
□ Albedo = the proportion of energy that is reflected back to the atmosphere. radiation is inversely
5. Long-wave radiation ▪ Varies with colour (light materials are more reflective than dark materials).
6. Latent heat (evaporation and condensation)
▪ Grass has an average albedo of 20-30%, meaning that it reflects back about
20-30% of the radiation it receives. [3] Surface and sub
Energy can be lost by absorption, scattering and reflection: □ Clouds contain water droplets or ice crystals which reflect insolation. □ Energy
the nat
▪
1. Absorption - certain wavelengths of shortwave
radiation can be absorbed by gases in the atmosphere ▪
(ozone, water vapour, CO2), clouds, dust and haze. Both incoming solar radiation and reflected solar radiation are shortwave radiation. □ Heat tr
surface
radiation. This radiation is absorbed by clouds, atmospheric gases and the Earth's
The
con
cold
surface. Some parts of the Earth receive more of this radiation than others. The main
Wednesday, April 12, 2023 4:27 PM reason for this is the curvature of the Earth. This curvature means that, at higher the
latitudes, the radiation from the sun is spread over a much larger surface area, while the fact
same amount of energy is much more concentrated near the equator. The radiation of a
An energy budget refers to the amount of energy Global scale = macro-scale also travels through a greater depth of atmosphere nearer the poles, in comparison to rad
entering a system, the amount leaving the system Local scale = micro-scale the equator so more radiation is lost to scattering and absorption by gases and particles Ear
and the transfer of energy within the system.
in the atmosphere.
Night-time energy budget No insolation and reflected solar radiation
Higher temperatu
1. Long-wave Earth radiation emits shorter wa
2. Latent heat transfer (condensation)
3. Absorbed energy returned to Earth (sub-surface supply)
4. Sensible heat transfer
Daytime energy budget Blackbody radiation
Assumes a horizontal surface with grass-covered soil
Blackbody radiation
Energy available at the surface = incoming solar radiation - temperature, and th
(reflected solar radiation + surface absorption + sensible heat
transfer + long-wave radiation + latent heat transfers) A perfect black body
[1] Incoming (shortwave) solar radiation/insolation is the main energy input. it and emits, at any
□ Affected by latitude, season and cloud cover (the less cloud cover there is, bodies do not really
1. Incoming (shortwave) solar radiation (insolation)
and/or the higher the cloud, the more radiation reaches the Earth's surface). and the sun) as blac
2. Reflected solar radiation
3. Surface absorption
4. Sensible heat transfer [2] Reflected solar radiation Wien's displacemen
□ Albedo = the proportion of energy that is reflected back to the atmosphere. radiation is inversely
5. Long-wave radiation ▪ Varies with colour (light materials are more reflective than dark materials).
6. Latent heat (evaporation and condensation)
▪ Grass has an average albedo of 20-30%, meaning that it reflects back about
20-30% of the radiation it receives. [3] Surface and sub
Energy can be lost by absorption, scattering and reflection: □ Clouds contain water droplets or ice crystals which reflect insolation. □ Energy
the nat
▪
1. Absorption - certain wavelengths of shortwave
radiation can be absorbed by gases in the atmosphere ▪
(ozone, water vapour, CO2), clouds, dust and haze. Both incoming solar radiation and reflected solar radiation are shortwave radiation. □ Heat tr
surface
