1 - Energy in the Atmosphere Flashcards
Where is most of the air mass?
Troposphere consists 90% of the air mass
Stratosphere contains ozone layer
Why is dry air analysed?
Average air composition. Water causes chemical fluctuations
Forms of energy?
Kinetic, potential, heat, chemical, radiation (high wavelength, low energy)
Wien’s law
objects at different temperatures emit spectra at different wavelengths
Inverse relationship. Peak wavelength depends on temperature.
Black body
An idealised physical body which absorbs all incident radiation regardless of frequency or angle. smooth spectrum. Emit radiation in a range of wavelengths according to Planck’s curve - smooth spectrum
Stefan Boltzmann law
Total emitted energy increases with temperature
Doubling T is extreme - T4
Why does the sun radiate at a shorter wavelength?
Higher surface temperature thus more radiation and higher energy
Shortwave radiation?
Reflection, scattering, absorption, re-emission
Why are incoming and outgoing fluxes almost equal? *(check)
Due to dynamic state equilibrium. Climate responds to changes in radiation primarily through chemical weathering
Why is most absorption over tropical areas? *
Highest level of incoming radiation (direct), more clouds which can absorb radiation and no ice albedo effect
How is energy transferred laterally?
Sensible heat, latent heat and ocean currents
Why do deserts cool and heat more quickly than the ocean?
Lower heat capacity and thus faster response time
Why is there seasonal variations in co2? *
Most decomposition occurs from fall to spring (increased co2) and most photosynthesis during spring to fall. Also influenced by Milankovitch and sub Milankovitch cycles
Why is there the opposite seasonal cycle for o2? *
Inverse relationship. During summer there is low co2 but high o2 due to increased photosynthesis where o2 is a biproduct
Where does weather occur?
Troposphere
Kinetic energy
energy which a body posses by being in motion
Chemical energy
electrical energy bound in the chemical structure of a substance, and can be released via kinetic or thermal energy.
Potential energy
energy held by a body due to its position. Related to gravity
Sensible heat
amount of heat required to change the temperature of a substance without altering its phase. E.g. when the temperature of a body declines, the heat removed is the sensible heat (can be felt). I.e. changes temperature
Latent heat
energy absorbed or released by a substance during a change in state, without changing temperature. i.e. changes state
Explain diurnal variation?
At dawn the sun is low in the sky and radiation will be spread over a larger area. This area will decrease as the sun rises, thus intensity increases particularly in areas where the incident angle is lowest (equator). The length of day also influences radiation received; at the equator approximately 12 hours of sunlight is received.
Explain seasonal variations in insolation?
This is due to the changing direction of tilt of the Earth relative to the sun and the eccentricity of Earth’s orbit. Earth is closest to the sun in perihelion (January) and furthest in Aphelion (June)
How is energy balance maintained?
By net poleward transfer of heat, feeding higher latitudes and draining lower latitudes to reduce extremes.
