the atmosphere

• Reflected by earths surface = 8.8%
• Absorbed by earths surface = 49.1%
• The first two layers of the atmosphere are called the troposphere and the stratosphere.
• The boundaries between layers are called the tropopause and the stratopause.
• Altitude is the height above sea level.
• Pressure decreases with altitude because there are less particles and this causes the temperature to decrease with altitude.
• The troposphere is unstable and sometimes cold air sinks below the hot air and causes weather.
• Nitrogen gas makes up 78% of the atmosphere by volume.
• Oxygen gas makes up 21% of the atmosphere by volume.
• Water vapour makes up 0-4% of the atmosphere by volume.
• Carbon dioxide makes up 0.04% of the atmosphere by volume.
• Methane makes up 0.0002% of the atmosphere by volume.
• Nitrous oxide makes up 0.00003% of the atmosphere by volume.
• Ozone makes up 0.000004% of the atmosphere by volume.
• Di-nitrogen gas is important for life because its used for protein synthesis and bacteria use it for respiration.
• Oxygen gas is important for life because it is involved in aerobic respiration.
• Carbon dioxide is important for life because its involved in photosynthesis and is a green house gas.
• Ozone is important for life because it absorbs UV light and prevents genetic damage/mutations.
• Transmitted by the atmosphere to the surface and reflected by the surface
• The earth receives lots of incoming short wave solar radiation (insolation) - This is because of the earths distance from the sun.
• Transmitted through the atmosphere and absorbed by the earths surface
• The ozone molecule is unstable and UV radiation splits it back into diatomic oxygen with a single atom and repeats the process.
• Short wavelength = high frequency
• Snow, ice and clouds reflect lots of energy off the earths surface, the ocean absorbs lots of energy.
• Some radiation is re-absorbed by the earth after being re-emitted.
• The atmosphere came from the breakdown of volcanic minerals into water vapour, there was no oxygen.
• 4 processes:
• Absorbed by the atmosphere and clouds
• Outgoing long wave radiation Is long wave infra-red.
• UV radiation makes its way through the atmosphere until 25km above sea level where it is absorbed by oxygen and splits the molecules into 2 single atoms - they bond to diatomic oxygen to form ozone.
• Reflected by atmosphere and clouds
• Some radiation is reflected off of clouds, some is absorbed by the earths surface and re-emitted back into space.
• The % if incoming radiation reflected by the earths surface is called albedo
• The incoming radiation is 7% UV, 43% visible light and 49% short wave IR.
• Wavelength is peak to peak or trough to trough.
• Frequency of a wave is the number of waves passing a point per minute.
• Long wavelength = low frequency
• There was lots of methane and ammonia which overtime converted into carbon dioxide and nitrogen gas.
• The evolution of life produced photosynthetic organisms that converted carbon dioxide into oxygen.
• 80% of all gases are in the troposphere because gravity pulls them downwards.