ATMOSPHERIC FACTORS

1 - Carbon dioxide - carbonate rocks, combustion, volcanic activity, ocean equilibrium,
     plant, animals, oxidation of organic compounds.
     A - overall atmospheric increase. May also be localized depletion - intensive crops, forest tree crowns.
     B - Greenhouse effect - infra-red (heat) absorbed and re-radiated back to earth. Causes warming
          of earth's surface. Control of global temperature:
          a - amount of water vapor - constant over long period of time.
          b - source of increased carbon dioxide - burning of fossil fuels. Progressive increase documented -
               ancient air sampled in glacial ice - trapped bubbles 200-300 ppm
               160,000 years ago. Level maintained until about 130 years ago (Industrial Revolution).
               Progressive Rate of increase - currently 0.5% per year, today approx 350 ppm,
               most tied up in sinks.
          c - additional gases - methane, ozone, nitrous oxide, CFC
     C - Rate of temperature increase - evidence from last several decades indicates increase 0.5oC
          Results in:
          a - change pattern of precipitation, frequency and intensity of violent storms
          b - rise in sea level - as much as 12 inches in next century

2 - Sulfur dioxide - reaction with water
     Forms sulfuric acid in micro-droplets
     Rain may have a pH of 3.5
     Interaction with ozone may have synergistic incluence
     Damage - Sudbury, Ontario and Copper Basin, Tennessee - extensive de-forestation.
     Severe gully erosion, original type of vegetation cannot be re-established.
     Camel's Hump - 1968 study, cloud water pH
     3.7, progressive decline and death of red spruce
     Wald sterben - death of European forests

3 - Nitrogen compounds - oxides produced primarily from combustion process, form oxides
     when gaseous nitrogen reacts with atmospheric oxygen.
     Associated with smog - peroxyacetyl nitrates, damage, silvering of leaves.

4 - Ozone - fresh air, lightning. Elevated concentration causes damage - weather
     fleck of tobacco

5 - Florides - injury less than 1 ppb, sources - industrial processes, damage involves - chlorosis, tip necrosis

6 - Chlorine - damage involves bleaching and necrosis

7 - Pesticides - half life, target, toxicity, fate in environment

8 - Particulate matter - smoke, dust, biological (pollen, spores)
     Distribution of atmospheric components - Wind
     cause - rotation of earth, uneven heating
     Influences:
     1 - transpiration - cooling, boundary layer
     2 - form - cushion plants
          Dwarfing
          Wind
          Breakage, lodging
     3 - erosion, deposition
     4 - pollination