Unit 3 Atmospheric Science Air Pollution Atmosphere Atmosphere

Unit 3 “Atmospheric Science & Air Pollution”

Atmosphere • Atmosphere – thin layer of gases that surround the earth; composed of 5 sub layers – 1. Troposphere – closest to the earth, has most oxygen of any of 5 – 2. Stratosphere – Ozone predominantly found here – 3. Mesosphere – Ionosphere (weakly charged ions) located in upper portion – 4. Thermosphere – increase in temperature; uppermost portion of Ionosphere located here – 5. Exosphere – interface between earth’s atmosphere and space; very few gases

Atmosphere

Atmospheric Properties • Composition of gases: 78% N, 21% O, 1% trace gases • As altitude increases, pressure ______. Why? • As altitude increases (exception in thermosphere), temperature ______. Why? • As altitude increases, density ______. Why? • http: //video. nationalgeographic. com/video/101 videos/weather-101 -sci

Ozone Layer • Found in the Stratosphere and is composed of O 3 molecules • Blocks UVA and UVB rays from reaching earth’s surface • In the latter part of the 20 th century, due to the use of products containing CFC’s, the Ozone Layer was depleted • In the 1990’s many governments banned the use of CFC’s; as a result, the hole in the Ozone was reduced

Ozone Layer Depletion • Keeping Ozone Layer intact is important because it keeps harmful UV rays from reaching the earth’s surface thereby preventing skin cancer

Current Ozone Layer Conditions • Good News…. Recent research shows ozone hole has shrunk by more than 4 million square kilometers • http: //www. breitbart. com/biggovernment/2017/03/28/report-ozone-holehas-shrunk-by-more-than-4 -million-squarekilometers/

Weather and Climate • Weather – day to day fluctuations in temperature and precipitation • Climate – average weather conditions from year to year • Whatever the conditions are in the atmosphere, those conditions will affect weather, and lastly climate

Air Masses and Pressure Systems • Cold air mass = high pressure system • Warm air mass = low pressure system • As is the case with ocean currents, there are horizontal and vertical air currents • Vertical air currents are called Convection Currents (hot air or fluid expands and is therefore less dense than its cooler surroundings, thus it rises; as it cools it contracts, becomes more dense and sinks down creating something of a rolling motion)

Air Masses and Pressure Systems • Also, the ocean’s physical conditions (temperature etc. ) affect the physical conditions of the atmosphere and vice/versa • Evidence of how the ocean’s physical conditions affect atmosphere/weather is the occurrence of hurricanes (require warm ocean water to develop) • http: //sciencelearn. org. nz/Contexts/H 2 O-Onthe-Go/Sci-Media/Video/Water-and-weather

Air Pollutants • Primary Pollutants – emitted into the troposphere already in a form that is harmful to life in the biosphere – Example CFC’s • Secondary Pollutants – result of primary pollutants reacting with each other or other substances in the atmosphere to form new pollutants – Example Acid Rain

Air Pollutants • Acid Rain – sulfur dioxide from coal burning power plants combines with water vapor • Smog – coal and/or oil soot is released into the air • Particulate pollution – small solid particles released into the air as a result of industrial processes; results in asthma and other respiratory ailments

Mitigating Air Pollutants • Just as the Clean Water Act was put in place to protect the hydrosphere, the Clean Air Act was put into effect beginning in the 1960’s to protect the atmosphere • The Clean Air Act of 1990 - intent was to strengthen standards instituted in the 1970 version of the act; it also introduced an emissions trading program for sulfur dioxide (acid rain)

Market Based Incentives versus Government Regulations • Incentives = voluntary; if done properly provide an economic incentive to industry to “clean up their act” • Regulations = involuntary; government requires industry to comply with regulations, sometimes causing them to become less competitive • Which is better? It depends on the variables involved!

Climate/Atmosphere/Meteorology Summary • https: //www. youtube. com/watch? v=lr. PS 2 Hi. Y Vp 8&index=13&list=PLIDao 9 d 2 upp 5 Q 3 ff. AXK 0 3 Ocjf. LQHUGK 3 b