TROPOSPHERIC OZONE 1 Ozone cosists of three oxygen molecules Polar molecule, like water Ozone is much more reactive, unstable OZONE 2 LAYERS OF ATMOSPHERE 3 4 OZONE TROPOSPHERIC ▪Called “Bad Ozone” ▪Acts as pollutant ▪Pale blue, poisonous gas ▪Measured in ppb STRATOSPHERIC ▪Called “Good Ozone” ▪Acts as protective layer ▪Absorbs ultraviolet radiation ▪Measured in DU (Dobson Unit) 5 WHAT IS TROPOSPHERE? I. THINNEST LAYER OF ATMOSPHERE II. HOLDS ~80% EARTH’s ATMOSPHEREIC MASS III. MOST WEATHERS COME HERE IV. 10% OZONE PRESENT HERE V. KNOWN AS BAD OZONE 6 FORMATION OF TROPOSPHERIC OZONE TROPOSPHERIC OZONE FORMED DUE TO : • Hydrocarbons, which are released by plants and soil. • STRATOSPHERIC OZONE , small amount migrating downward. • Byproduct of certain human activities , cause ozone formation here. And this is what we think of as 'bad' ozone. •With increasing populations, more automobiles, and 7 • Since 1900 the amount of ozone near the earth's surface has more than doubled. • TROPOSPHERIC OZONE FORMED BY : 1 2 4 Nox + Nox (oxides of nitrogen) VOCS (volatile organic compounds) Sunlight VOCS + Sunlight = OZONE 8 9 Tropospheric ozone formation 10 SOURCES OF NO x 1) 2) 3) 4) 5) COME FROM COAL-FIRED POWER PLANTS AUTOMOBILES DIESEL TRUCKS AND BUSES FARMING AND CONSTRUCTION EQUIPMENT BOATS, AND TRAINS SOURCES OF VOCS 1) COME FROM GASOLINE COMBUSTION 2) THE EVAPORATION OF LIQUID FUELS, SOLVENTS AND ORGANIC CHEMICALS ...
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