The Atmosphere Flashcards
What is the composition of the atmosphere?
Nitrogen - 78%
Oxygen - 21%
Carbon dioxide - 0.04%
Rare gases (combined) - 1%
Ozone - 0.000007%
Why are there daily fluctuations in CO2 concentrations?
0-7 — respiration, no photosynthesis.
7-12 — photosynthesis > respiration.
12-16 — photosynthesis = respiration.
16-24 — respiration > photosynthesis.
How do gases for natural processes support life?
Atmosphere contains carbon, nitrogen, oxygen and hydrogen.
These are needed to make biological molecules for living organisms.
How does the absorption of electromagnetic radiation from the Sun support life?
Biologically damaging radiation in the ‘solar wind’ is prevented from reaching Earth by the upper atmosphere.
O, O2 and O3 work together to form a dispersed layer in the stratosphere called the ozone layer.
These gases absorb UV light, producing a dynamic equilibrium of chemical reactions which form and destroy ozone.
How does delaying the escape of infrared energy support life?
Much of the incoming visible light is absorbed, converted to heat, and re-emitted as infrared energy. Naturally occurring atmospheric gases absorb this infrared energy, convert it to heat and increase the temperature of the atmosphere.
Warm atmosphere emits infrared radiation which is absorbed by Earth’s surface.
Warm atmosphere reduces heat loss by conduction from land and oceans.
How does heat distribution support life?
Most of the energy form the Sun, absorbed at the Earth’s surface, is absorbed in tropical regions.
Warm surface heats the atmosphere above and this heat is distributed to higher latitudes by warm winds, such as the south-westerly winds that bring heat energy to the UK from the Caribbean Sea.
How do ocean currents support life on Earth?
Winds blowing over the oceans create currents that distribute heat by carrying warm water from tropical areas to high latitudes, such as the North Atlantic Conveyer.
How does the transport of water vapour support life on Earth?
Winds transport water vapour to areas that would otherwise get little or no precipitation.
