ozone depletion....varun

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  • Ozone depletionk.Varun kumar

  • What is ozone?Ozone is a triatomic form of oxygen found in earths upper and lower atmosphere.The layer is a layer absorbs 97%-99% of the suns high frequency ultraviolet light, which s potentially damaging to the forms on earth

  • What is ozone layer?The ozone layer is a layer in earths atmosphere which contains relatively high concentrations of ozone (O3). The ozone layer, situated in the stratosphere about 15 to 30 km above the earths surface.Ozone protects living organisms by absorbing harmful ultraviolet radiation (UVB) from the sun. The ozonelayer is being destroyed by CFCs and other substances.Ozone depletion progressing globally expect in the tropical zone.

  • How hole is formed?A combination of low temperatures and elevated chlorine and bromine concentrations are responsible for the destruction of ozone layer in the upper stratosphere thus forming a hole.

  • Also caused by the green house gases which are released by industries and vehicles

  • Meteorological mechanismMoment of air from one place to another in the upper stratosphere.Cold temperature in the upper atmosphere causes nitric cid to freeze into crystals forming wispy pink clouds.

  • Effects o plant growth

  • What are the effects of over exposure to UV rays ?Skin cancerEye damage such as cataractsImmune system damageReduction in phytoplanktonDamage to DNA in various life-forms ( this has been observed in Antarctic ice-fish that lack pigments to shield them from ultra violet which they have never needed them before)

  • Cont.Overexposure: increase risk of non-melanoma and malignant melanoma and malignant melanoma skin cancerPossibly other things too that we dont know about them

  • Skin cancer

  • phytoplanktonPhytoplankton: (phytoplankton uses carbon dioxide, releases oxygen, and converts minerals to a form that animals can use)

  • cataracts

  • Damage of immune system

  • Damage of DNA

  • How to protect ozone?Minimize high altitude aircrafts (oxygen reduction and water vapour deposition)Minimize rocket flight ( water vapour deposition)Encourage growth of plants that produce that produce oxygen, discourage deforestationDecrease/ control release of known ozone depleting chemicals (such as CFCs chlorine fatigue syndrome) where remotely possible. Subsidize production of safer alternatives where possible.

  • Actions taken individuallyDont use the car so muchTurn of the lights and the faucet when not in useUse blankets to stay warm in the winter, wear thinner clothes in the summer to stay cool instead of an A.CTry to use products which are labeled ozone-friendly

  • ContVehicle air conditioning units should regularly be checked for leakEnsure technicians repairing your refrigerator or air conditioner recover an recycle the old CFCs so they are not released into the atmosphereSuggest school activities to increase awareness of the problem and to initiate local actionMinimize industrial refrigerators which releases chlorine

  • CFC-12 released in troposphereCarried into stratosphere in the tropics by slow rising circulationCFC-12 photolyzed in stratosphere by solar UV, releasing ClCl catalytically destroys O3Cl reacts with CH4 or NO2 to form non-reactive HCl or ClONO2Cl released by PSCsHow does chlorine get from our refrigerators to the Antarctic stratosphere?

  • Now you decide

  • Thank you

    *The life cycle of the Cl atom. All of Cl that makes it into the stratosphere is lifted into the stratosphere at the tropical tropopause. CFCs are very non-reactive. The pathway from the troposphere to the stratosphere takes about 5-6 years.CFC-12 photolysis rate ~ 1/(100 days) at 25 kmCFC-11 photolysis rate ~ 1/(1000 days) at 25 km