Atmosphere 2- climate change and air quality Flashcards
What type of radiation is emitted by all objects?
electromagnetic
What is the spectrum of electromagnetic radiation emitted determined by?
temperature of the object
What does a higher temp do to wavelength?
results in a shorter wavelength
What would the temp of earth be without greenhouse effect?
~-20*c
What is the greenhouse effect?
the increase in the surface temperature of the Earth as a consequence of the presence of an overlying atmosphere
What does the greenhouse effect arise as a result of?
Temperature dependence of emission spectra (Earth vs. Sun)
Differing absorption properties of Earth’s atmosphere towards Visible / IR radiation
What wavelength is most incoming solar radiation?
visible wavelength
What wavelength is most outgoing terrestrial radiation?
Far IR (infrared) wavelength
What is the absorbance of atmospheric constituents like in relation to IR?
Absorb more IR than visible light
What are some examples of greenhouse gases?
H2O
CO2
CH4
NO2
How would earth be described without the greenhouse effect?
Snowball- completely frozen
What is radiative forcing (RF)?
measure of the influence that a factor has in altering the balance of incoming and
outgoing energy in the Earth-atmosphere system
What does positive and negative radiative forcing tend to be like?
Positive- warm the surface
Negative- tends to cool surface
How is radiative forcing expressed?
W m*2
How is radiative forcing calculated?
off pre industrial levels from 1750
What is the IPCC?
Intergovernmental panel on climate change