Springtime Ozone Data

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					 Earth’s Atmosphere




Strahler, A. and Strahler, A., 2004. Physical Geography. Wiley, NY.
  Chapman Mechanism
O2 + UV  O + O

O + O2 + m  O3 + m + heat

O3 + UV  O + O2

O + O3  2O2 + heat
Catalytic Reactions

 X + O3  XO + O2

  XO + O  X + O2

Catalysts include OH, H, NO, and Cl.
 Three Types of Ultra Violet
UV-A (320 – 400 nm)
   Negligibly absorbed by O3 layer.

UV-B (290 – 320 nm)
   Mostly absorbed by O3 layer.

UV-C (< 290 nm)
   Totally absorbed by O3 layer.
Effects of Excessive Exposure
        to UV Radiation
   Skin cancer (basal and squamous cell
    carcinoma and melanoma).
   Cataracts.
   Immune system depression.
    photosynthesis, water use
    efficiency, leaf area and yield.
    growth of marine phytoplankton,
    zooplankton, and fish larvae.
     Chlorofluorocarbons
   First synthesized by Thomas
    Midgley Jr. in 1930.
   Non-toxic, non-flammable,
    inexpensive, non-odorous and
    versatile.
   Uses include: coolant, foam
    production, aerosol propellant,
    and solvent.
          Uses of CFCs 1986
              5% Aerosol propellant &
                miscellaneous uses
22% Unallocated                   12% Solvent
production                         for metal &
                                   electronics

19%                                4%
Mobile air                         Sterilization
conditioning                       of medical
                                   equipment

9% Refrigeration                 28% Production
& stationary air                 of plastic foam
conditioning                     & insulation
       Global CFC Use 1986
              14% Other developing countries

2%
China
and India

14%
Warsaw Pact
countries                             70%
                                      Industrial
                                      countries
Other Ozone Depleting
     Substances

    Carbon tetrachloride.
    Methyl chloroform.
    Halon.
    Methyl bromide.
   Process of Depletion
Photodissociation:
       CF2Cl2 + UV  CF2Cl + Cl
Destruction:
          Cl + O3  ClO + O2
Regeneration:
           ClO + O  Cl + O2
Destruction:
         ClO + O3  ClO2 + O2
  Termination Reactions
Termination agent: nitrogen dioxide
      NO2 + ClO  ClNO3

Termination agent: methane
    CH4 + Cl  HCl + CH3
    HCl + OH  Cl + H2O
    Nitric Oxide and Ozone
   Liberation of chlorine:
         NO + ClO  NO2 + Cl
   Regeneration:
     NO2 + visible light  NO + O
   Catalytic decomposition of ozone:
         NO + O3  NO2 + O2
          NO2 + O  NO + O2
Anthropogenic Sources of
    Nitrogen Oxides
   Use of nitrogenous fertilizers.
   High altitude aircraft.
   Detonation of nuclear
    weapons.
Springtime Ozone Data




http://www.cmdl.noaa.gov/ozwv/ozsondes/spo/ozdob.html
Antarctica




 http://www.travellers
 point.com/map.cfm?
 country=Antarctica
    Ice Crystal Reactions

   Stable chlorine transformed
    into reactive forms.
   Termination agents
    neutralized.
     Restoration Factors
   Ozone rich tropical air
    migrates poleward.
   Local production of ozone
    occurs.
   Icy stratospheric clouds
    disappear.
      Path to the Protocol
1976: Manufacture of CFC aerosol spray
  cans for non-essential uses banned by
  several countries.
1977: Coordinating Committee on the
  Ozone Layer established by UNEP.
1981: Decision to develop a global
  convention.
1985: Vienna Convention on Substances
  that Deplete the Ozone Layer signed.
      Montreal Protocol I
   Signed in September 1987.
   Initially 50%  production and
    consumption of CFCs and halons
    by 1999.
   Ban on import from non-signatory
    countries.
    Montreal Protocol II
   10 year grace period for low
    income countries.
   Monitored by international
    scientific panel.
   In effect 1 January 1989.
   Baseline year is 1991.
            Amendments
   London in 1990, Copenhagen in 1992,
    Vienna in 1995, Montreal in 1997.
   100%  in production and consumption
    of CFCs and halons by 2000.
   Other ODS added: carbon
    tetrachloride, methyl chloroform,
    HCFCs, HBFCs, methyl bromide.
   International fund established.
    Alternatives to ODS
       Requirements
   Perform same function.
   Reasonable cost.
   Without major equipment
    modifications.
   Environmentally benign.
   Non-toxic to workers and
    consumers.
Alternatives to ODS
     Examples
      HCFCs.
      Ammonia.
      Propane.
      Bioact EC7.
      CF3I.
    Efficiency in ODS Use
   Use of solvents in closed
    system with recycling of
    captured CFCs.
   Plugging leaks in cooling
    systems.
   Suction systems and carbon
    adsorption to recover CFCs.
  Methyl Bromide Exemptions
            2005
Country           MB tonnes Country                  MB tonnes
Australia         145               Japan            284
Belgium           47                Portugal         50
Canada            55                Spain            1059
France            407               UK               128
Greece            186               USA              8942
Italy             2133
        http://www.pan-uk.org/pestnews/pn64/pn64p18.htm
Factors for the Success of the
      Montreal Protocol
     Clear & ongoing science.
     Negotiations.
     Funding for low income countries.
     Industry recognized advantage of
      developing alternatives.
     Alternatives.
     Licensing system.
     Annual statistical data.

				
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posted:11/3/2012
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