Pollution!Pollution!

By: Stephanie OhBy: Stephanie Oh

IntroductionIntroduction• The air is always moving. The air is always moving.

Convection currents and wind Convection currents and wind keep air circulating around keep air circulating around the Earth. Even polluted air the Earth. Even polluted air moves away and becomes moves away and becomes replaced by fresh air. But replaced by fresh air. But sometimes the air isn't able to sometimes the air isn't able to circulate which is how circulate which is how pollutants accumulate. It pollutants accumulate. It accumulates due to the accumulates due to the natural process of nature for natural process of nature for billions of years. The billions of years. The accumulation of pollutants accumulation of pollutants kills hundreds of thousands of kills hundreds of thousands of people each year around the people each year around the world. world.

Air pollution?Air pollution?

• Air pollution is toxics that get stuck in one Air pollution is toxics that get stuck in one area for too long and start to clump together, area for too long and start to clump together, it causes many health and environmental it causes many health and environmental problems. problems.

Sources and CausesSources and Causes• When we talk about air When we talk about air

pollution, it means gasses and pollution, it means gasses and dust in the atmosphere that dust in the atmosphere that don't occur naturally.don't occur naturally.

• Air pollution comes from Air pollution comes from natural and manmade natural and manmade sources. But the main cause sources. But the main cause is manmade pollutants, for is manmade pollutants, for example: construction, example: construction, mining, agriculture, nuclear mining, agriculture, nuclear power plants, oil tankers, and power plants, oil tankers, and most importantly cars.most importantly cars.

• The explosion of the The explosion of the population, is also a factor population, is also a factor contributing toward the contributing toward the growing air pollution problem.growing air pollution problem.

Environmental Issues and Environmental Issues and Weather PatternsWeather Patterns

• Pollution is a consequence for Pollution is a consequence for natural disaster. For example natural disaster. For example hurricanes which involve water hurricanes which involve water contamination from sewage, and contamination from sewage, and oil spills from ruptured boats or oil spills from ruptured boats or automobiles. automobiles.

• Scientists observing a NASA Scientists observing a NASA satellite say that air pollution from satellite say that air pollution from humans is likely to cause more humans is likely to cause more rainfall and storms in the South-rainfall and storms in the South-eastern United States. eastern United States.

Air Convection and CurrentsAir Convection and Currents

• Air currents are the continuous movement of Air currents are the continuous movement of air transferring heat from the equator to the air transferring heat from the equator to the poles and vice-versa. At the equator heated, poles and vice-versa. At the equator heated, moist air flows upwards. moist air flows upwards.

• They are caused by the differences in They are caused by the differences in temperature and pressure. Temperature temperature and pressure. Temperature differences can cause air currents because differences can cause air currents because warmer air is less dense than cooler air, warmer air is less dense than cooler air, causing the warmer air to appear “lighter”. causing the warmer air to appear “lighter”. So if the warm air is under the cool air, air So if the warm air is under the cool air, air currents will form as they exchange places. currents will form as they exchange places.

• Pressure differences also cause air currents Pressure differences also cause air currents as the air flows from areas of higher pressure as the air flows from areas of higher pressure to areas of lower pressures, and hot air rises.to areas of lower pressures, and hot air rises.

Convection CurrentsConvection Currents

• An example of convection An example of convection currents are birds who float currents are birds who float upward on rising currents upward on rising currents towards the warm air. towards the warm air.

• Convection currents help Convection currents help disperse air, including any disperse air, including any pollutants in the air. This pollutants in the air. This natural force moves polluted natural force moves polluted air rising and dilutes it in less-air rising and dilutes it in less-polluted air above. Due to polluted air above. Due to convection, air pollution convection, air pollution doesn't remain isolated or doesn't remain isolated or localized. But a temperature localized. But a temperature inversion can change normal inversion can change normal convection currents. convection currents.

• Convection currents are always Convection currents are always hot rising and cool falling. hot rising and cool falling.

How do Temperature How do Temperature Inversions Form?Inversions Form?

• Temperature inversions play a huge Temperature inversions play a huge role in the air quality. A temperature role in the air quality. A temperature inversion occurs when a mass of warm inversion occurs when a mass of warm air moves over a cooler, surface air. air moves over a cooler, surface air. This warm air forms a lid over the area, This warm air forms a lid over the area, trapping all the polluted air left from the trapping all the polluted air left from the city’s transportation systems, city’s transportation systems, industries, and homes. The inversion industries, and homes. The inversion traps pollutants near the ground, traps pollutants near the ground, leading to poor air quality. If a leading to poor air quality. If a temperature inversion traps pollutants, temperature inversion traps pollutants, then a visible layer of smog will appear.then a visible layer of smog will appear.

• During the day time, the sun heats the During the day time, the sun heats the surface of the Earth and the layer of air surface of the Earth and the layer of air closest to the Earth. This warm air rises closest to the Earth. This warm air rises and mixes with other atmospheric and mixes with other atmospheric gases. When the sun goes down a gases. When the sun goes down a temperature inversion takes place. The temperature inversion takes place. The less dense warm air thats high up less dense warm air thats high up provides a blanket for the colder air. provides a blanket for the colder air. The colder air is trapped close to the The colder air is trapped close to the Earth because it's less dense and the Earth because it's less dense and the atmospheric gases don't mix. atmospheric gases don't mix.

SmogSmog• In busy cities like San In busy cities like San

Francisco you can Francisco you can sometimes see haze that sometimes see haze that forms over the city. forms over the city. Sources include Sources include motorized vehicles, motorized vehicles, industries, airplanes, industries, airplanes, trains, wood stoves, and trains, wood stoves, and wildfires. Smog occurs wildfires. Smog occurs due to convection due to convection currents becoming currents becoming effected from effected from temperature inversions. temperature inversions.

• Smog usually stays until Smog usually stays until the morning sun warms the morning sun warms the air enough to begin the air enough to begin the mixing of the the mixing of the convection cycle.convection cycle.

Work Cited PageWork Cited Page

• http://www.cite-sciences.fr/lexique/definition1.php?lang=an&id_expo=13&id_habillage=24&iddef=456http://www.cite-sciences.fr/lexique/definition1.php?lang=an&id_expo=13&id_habillage=24&iddef=456&idmot=168&idmot=168

• "Air Currents ." Resources and Lexicon (2004) <http://www.cite-sciences.fr/lexique/definition1.php?"Air Currents ." Resources and Lexicon (2004) <http://www.cite-sciences.fr/lexique/definition1.php?lang=an&id_expo=13&id_habillage=24&iddef=456&idmot=168>.lang=an&id_expo=13&id_habillage=24&iddef=456&idmot=168>.

• http://en.wikipedia.org/wiki/Pollutionhttp://en.wikipedia.org/wiki/Pollution

• Everyone. "Pollution." Wikipedia. 2001. Jimmy Donal. 13 December 2001 Everyone. "Pollution." Wikipedia. 2001. Jimmy Donal. 13 December 2001 <http://en.wikipedia.org/wiki/Pollution>.<http://en.wikipedia.org/wiki/Pollution>.

• http://maps.grida.no/go/graphic/dominating_air_currentshttp://maps.grida.no/go/graphic/dominating_air_currents

• "Dominating air currents." UNEP/GRID-Arendal Maps and Graphics Library. Unknown. UNEP/GRID-"Dominating air currents." UNEP/GRID-Arendal Maps and Graphics Library. Unknown. UNEP/GRID-Arendal. 5 Feb 2009 Arendal. 5 Feb 2009

• http://www.sciencedaily.com/releases/2008/02/080201215416.htmhttp://www.sciencedaily.com/releases/2008/02/080201215416.htm

• NASA/Goddard Space Flight Center. "Air Pollution May Be Causing More Rainy Summer Days In The NASA/Goddard Space Flight Center. "Air Pollution May Be Causing More Rainy Summer Days In The Southeast US." ScienceDaily 7 February 2008. 4 February 2009 Southeast US." ScienceDaily 7 February 2008. 4 February 2009 <http://www.sciencedaily.com/releases/2008/02/080201215416.htm><http://www.sciencedaily.com/releases/2008/02/080201215416.htm>

• http://www.newton.dep.anl.gov/newton/askasci/1995/environ/ENV114.HTMhttp://www.newton.dep.anl.gov/newton/askasci/1995/environ/ENV114.HTM

• Mortis. "Cause of Air Pollution." Ask A Scientist 4 February 2009 Mortis. "Cause of Air Pollution." Ask A Scientist 4 February 2009 <http://www.newton.dep.anl.gov/newton/askasci/1995/environ/ENV114.HTM>.<http://www.newton.dep.anl.gov/newton/askasci/1995/environ/ENV114.HTM>.

• http://www.weatherquestions.com/What_is_a_temperature_inversion.htmhttp://www.weatherquestions.com/What_is_a_temperature_inversion.htm

• http://www.infoplease.com/ce6/weather/A0848126.htmlhttp://www.infoplease.com/ce6/weather/A0848126.html