BESC 201 11 11 2013 Lecture 29 Outline of Last Lecture I Water Pollution Outline of Current Lecture II Chapter 13 Central Case Study III The Atmosphere IV Outdoor Air Pollution Current Lecture 11 11 2013 Atmospheric Science and Air Pollution Central Case Study L A and its Sister City Tehran Struggle for a Breath of Clean Air The Sister Cities program was devised to encourage world peace and understanding by fostering relationships between people of U S cities and others around the world Tehran s air is so bad that residents commonly wear face masks when they step outside Automobile traffic generates most of the pollution in Tehran Tehran s limited public transportation system forces most people to rely on cars motorcycles and taxis to get around 40 cent per gallon gas little incentive to conserve Each city lies in a valley surrounded by mountains that trap pollution The Atmosphere Atmosphere the payer of gases that surrounds Earth The atmosphere is layered Troposphere largely responsible for the planet s weather Stratosphere similar in composition to the troposphere but 1 000 times drier and less dense Ozone Layer greatly reduces the amount if UV radiation that reaches the Earth s surface The sun and the atmosphere drive weather and climate Convective Circulation warm air being less dense rises and creates vertical currents Weather specifies atmospheric conditions within small geographic areas over minutes hours or days These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Climate patterns of atmospheric conditions found across large geographic regions over seasons years or millennia Temperature Inversion departure from the normal temperature profile Inversion Layer the band of air in which temperature rises with altitude Because the normal direction of temperature change is inverted Storms pose hazards Hurricanes when winds rush into areas of low pressure where warm moisture laden air over tropical oceans is rising Tornadoes when a mass of warm air meets a mass of sold air and the warm air rises quickly setting a powerful convective current in motion Outdoor Air Pollution Air Pollutants gases and particulate material added to the atmosphere that can affect climate or harm people or other organisms Air Pollution the emission or release of air pollutants into the atmosphere We create outdoor air pollution Primary Pollutants pollutants emitted into the troposphere in a form that can cause harm or can react to form harmful substances Secondary Pollutants harmful substances produced once primary pollutants react with constituents of the atmosphere Residence Time the amount of time pollutants spend in the atmosphere Clean Air Act legislation addresses pollution in the United States Clean Air Act funds research on pollution control sets standards for air quality imposes limits on emissions from new sources and enables citizens to sue parties violating the standards The EPA sets standards for criteria pollutants Criteria Pollutants pollutants judged to pose especially great threats to human health Carbon Monoxide colorless odorless gas produced primarily by the incomplete combustion of fuel Sulfur Dioxide colorless gas with a pungent odor Nitrogen Dioxide foul smelling reddish brown gas that contributes to smog and acid deposition Nitrogen Oxides result when atmospheric nitrogen and oxygen react at the high temperatures created by combustion engines Tropospheric Ozone the pollutant that most frequently exceeds its EPA standard Particulate Matter composed of solid or liquid particles small enough to be suspended in the atmosphere and able to damage respiratory tissues when inhaled Lead a heavy metal that enters the atmosphere as a particulate pollutant
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