Environmental Science - 2.1.1 - Atmospheric Energy Processes, GHGs
describe the properties of UV radiation
wavelength is shorter than visible light
carries more energy than visible light
can ionise atoms
describe the properties of infrared radiation
has longer wavelengths than visible light
carries less energy than visible light
what does UV radiation help to create
the ozone layer, where UV-C dissociates oxygen molecules allowing them to form O3
how does IR contribute to the greenhouse effect
the energy of incoming sunlight is absorbed by the earths surface and re-emitted as IR
how does IR help to trap heat
certain greenhouse gases like water vapour and carbon dioxide absorb IR and retain the heat in the atmosphere
what can UV-B do
harms organisms by damaging proteins and DNA in skin cells
what can UV-A do?
although they have less energy, these waves can cause ageing of skin and trigger indirect damage to cell DNA
how does UV contribute to insolation
insolation is the amount of UV radiation that makes contact with the earths surface
what is the anthropogenic source of carbon dioxide?
deforestation due to lack of deforestation
buring fossil fuels due to combustion of sequestered carbon
what is the anthropogenic source of methane?
livestock digestion and agricultural practices
decay of disposed organic matter
what is the anthropogenic source of nitrous oxides?
incomplete combustion of fossil fuels in car engines
what is the anthropogenic source of CFCs?
old refrigeration systems, aerosols, and air conditioning
what is the anthropogenic source of tropospheric ozone?
photochemical breakdown and subsequent reaction with oxygen
what is the relative effects per molecule of carbon dioxide
1
what is the relative effects per molecule of methane?
25
what is the relative effects per molecule of nitrous oxides
160
what is the relative effects per molecule of CFCs
25000
what is the relative effects per molecule of tropospheric ozone
2000