- Ozone absorbs ultra violet radiation
- Protects from the burning effects of radiation
- Atmospheric composition has changed over time through volcanism and humans
- Current threats to atmosphere;
- C02 emissions contributing to global warming
- Hole in the ozone layer
- Acid rain from carbon monoxide/ sulphur oxide emissions
Structure of the Atmosphere
- Troposphere closest to surface
- 5-16km thick (thinner at poles and equator)
- where weather occurs
- drop in temp 1 C / 150
- Next closest layer (16-50km)
- Temp increase
- Ozone layer
- Jet stream in lower levels
- 50-80km – temp drops again
- Glow of ions attracted to magnetic poles
Pauses between spheres – transitions
Air pressure drops as you move away from earth
Above layers put pressure between layers
Most mass between 30km of earth
Insolation Interception of solar shortwave energy by an exposed surface
SW
Sun-earth
Strong, powerful,
Direct
LW- earth to atmosphere
Albedo- reflectivity of a surface (white or black)
Absorb- SW + LW more LW, O2 O3 H20, dust
Scattering – gas, dust, H20 droplets – scatter energy
Reflection – clouds, depend on thickness and nature and ice
H20 bodies higher albedo than land
Average albedo of earths surface 30%
March + Sept 21st – equinox, 0 degrees
June 23.5 S + Dec 23.5 N 21st – solstice
Pressure
- parts per unit of mass of the air
- Heat - ^ - low
- Elevation
- High elev. – L
- Low elev. – H
Measurement – Barometer kPa
