Process of Dry/Wet Deposition and Locations

Notes


Dry Deposition: Sulphur dioxide bonds with transpired water molecules on SA of leaf, causing the leaves to 'burn'

Wet Deposition: Conventional Acid Rain cycle

In Europe (prevailing wind travels NE)

- Dry deposition, where the sulphur dioxide is carried on wind currents, and is deposited on the top parts of trees in that region.

- Wet deposition, AFTER mountainous regions, where wind currents carrying sulphur dioxide condense, and bond with water molecules and acid rain occurs.

4.14 Enhanced Greenhouse Gases

Notes


GHE brought about by GHG (water vapour, carbon dioxide, methane)
  - Increased gases = increased amount of IR light re-emitted back to Earth, RAISE AVERAGE GLOBAL TEMPERATURE (Global Warming)

Consequences


-> Melting of ice caps in polar region = CLIMATE CHANGE
   - raised sea levels,
   - changing ocean currents
   - changing wind currents

-> Raising ave. global temperature = changes in distribution of biomes (major vegetation ecosytems)
  - polar ice-caps melts
  - Deserts expand
  - Deciduous, coniferous forests would change

4.13 Greenhouse gases

Notes


Human activity (fossil fuels) ---> Increased (CO2, NO2) <-- GHG & SO2


  - Industrial
  - Vehicles
  - Domestic (homes)
  - Farming = cows digest crops, emit methane gas to GHE (9% of gases)
  -Water vapour = clouds are main contributors
  - Refrigeration (CFCs) = absorption of UV light, catalysing breakdown of Ozone layer

4.12 Greenhouse Effect

Notes


a) UV light (sun) - Short wavelength, high energy

b) 50% reflected back out to space (before atmosphere penetration) = due to clouds

c) Absorption on Earth SA = UV light converted and emitted as infrared

d) Infrared light = emitted back towards outer space (Space - as heat)

Greenhouse effect


f) Greenhouse gases - Water vapour, CO4 , CH4


    - d) -- IR hits GHG --> f) =  g) absorbs energy BUT re-emitts in ALL DIRECTIONS (backdown, raising SA temp.).

4.11 Gas Pollution Consequences

Notes


Sulphur dioxide (SO2)


 - Combustion of fossil fuels, coals, oils
      - Factories
      - Vehicles

--> Sulphuric acid (SO2 + H2O) = Acid Rain
     - Vegetation: Leaves 'Burned' , Root system leached of magnesium and calcium = no growth
     - Lakes: Reduces Ph (acidic), brings aluminium ions = Al causes mucus thickening in fish,
fish not able to take in enough oxygen (suffocates)

Carbon monoxide


- Combustion of fossil fuels, coals, oils, with INSUFFICIENT OXYGEN

--> Bonds with Hb in RBC = Carbaminohaemoglobin, blocks Hb from carrying oxygen
   - Reduces oxygen circulation, toxic.