Atmosphere
- Created by: student111319
- Created on: 30-03-23 10:39
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The Atmosphere
- atmosphere is thin layer of gases surrounding earth, held in place by gravity
- is essential to life on earth as it provides vital life support systems e.g. protection from solar radiation
composition of the atmosphere:
- atmosphere composed of nitrogen, oxygen, carbon dioxide, rare + other gases
- nitrogen 78%, oxygen 21%, carbon dioxide 0.04%
- natural processes in state of balance which maintains tha average composition of atmopshere so it only changes over long timscales - dynamic equilibrium
- photosynthesis + aerobic repsiration important processes - balance each other out
- many processes affect atmosphere are interconnected, so one process changes it cuase changes in other - means that human actions can trigger sequence of events where human action changes one process which causes other processes to alter as direct result of first change
how the atmopshere supports life:
- gases for natural processes: atmosphere contains hydrogen, nitrogen, oxygen, carbon - are needed to make biological molecules used by living orgnaisms, they are extracted from atmosphere as N2 , O2, H2O . carbohydrates, lipids, protiens contain carbon, oxygen + hydrogen
- absorption of electromagnetic radiation from sun: biologically damaging radiation in solar winds prevented from reaching earth by upper atmospherem most ultraviolet light that passes through upper atmosphere is prevented from reaching earths surface by forms of oxygen present in atmopshere, element oxygen present in atmosphere in three froms with 1,2,3 atoms (O2, O, O3) , monatomic, diatomic + triatomic oxygen, together they form a dispersed layer in stratosphere called ozone layer, gases abosrb ultraviolet light procuding a dynamic equilibrium of chemical reactions whihc form + destroy ozone
- delaying the escape of infrared energy: incoming visible light is absorbed, converted to heat + re-emitted as infrared energy, naturally occuring atmospheric gases absorb infrared energy, convert it to heat + increase the temp of the atmosphere, raises temp of earth in two ways: warm atmosphere emits infrared energy which is abosrbed by earth surface, the warm atmosphere reduces heat loss by conduction from land + ocean
- heat distribution: most energy from sun absorbed at earth surface, is absorbed in tropical regions, warm surface heats the atmopshere above + this heat is distributed to higher latitudes by warm wind
- ocean currents: winds blowing over oceans creates currents that distribute heat by carrying warm water from tropical areas to higher latitudes e.g. north atlantic conveyor
- transport of water vapour: wind transport water vapour to areas that otherwise get no precipitation
atmospheric pressure:
- atmopsheric pressure contorls the ease which water molecules can evaporate + escape from the water surface, atmosphere pressure much lower = no liquid water on earth
- gases for human exploitation: humans extract variaty of industrially important gases from atmosphere e.g. oxygen, nitrogen
the structure of the atmopshere:
- altitude effects the composition + physical features of atmosphere resulting in series of layers, troposphere + stratosphere are affected by human activities
energy processes in the atmosphere:
- solar energy arriving at earth + energy being radiated to space in state…
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