Chapter 9: Atmospheric Pollution

Atmosphere

Air surrounding Earth;is made up of gases,including 78 percent nitrogen,21 percent oxygen,and 0.03 percent carbon dioxide.

Troposphere

Bottommost layer; (11 km, 7 mi) air denser near surface

stratosphere

2nd layer: 11-50 km (7-31mi) above surface: colder at lower boundary than upper boundary: Ozone absorb and scatter UV radiation

Ozone layer

layer that reduces the amount of UV radiation that reaches Earth's surface. (Earth's sunscreen!)

Atmospheric pressure

measure of the force per unit area produced by a column of air: decrease with altitude: 14.7 lb/in2 or 1013 mb, or , Force that air exerts on the surface of the body (760 mm Hg at sea level) measured by a barometer.

relative humidity

The comparison of the actual amount of water vapor to the amount of water vapor that would be in the air if it saturated.

seasons

caused by the 23.5 degree tilt of the Earth.

convection circulation

less dense warm air rises and creates vertical currents- as it rises into areas of lower atmospheric pressure it expands and cools, once it cools it descends and becomes denser and replaces the rising warm air

weather

The changes that take place in the lower part of the earth's atmosphere in a localized area during a short period of time

climate

Describes the average conditions, including temperature and precipitation, over long periods in a given area.

Mesosphere

3rd layer of atmosphere from surface

Thermosphere

upper layer of atmosphere (~300 mi)

warm front

The boundary between an advancing warm air mass and the colder air it is displacing

cold front

Forms when cold air moves under warm air which is less dense and pushes air up (produces thunderstorms heavy rain or snow.

high pressure system

Formed when an air mass cools over an ocean or a cold region on land. This dense system moves outward toward low pressure systems, creating a wind. Causes, clear blue skies, is dry etc.

low pressure system

air moves toward the low atmospheric pressure at the center of the system and spirals upward, clouds (precipitation)

thermal inversion

The temperature inversion in which warm air traps cold air and pollutants near the earth. London's killer smog 1952, LA, Mexico City, Seoul, Rio de Janeiro

Hadley Cell

The atmospheric circulation (vertical and horizontal) cell nearest the equator in each hemisphere. Air in these cells rises near the equator because of strong solar heating there and falls because of cooling at about 30° latitude. See also trade winds.

Ferrel Cells

atmospheric cells that circulate between about 30 degrees and 60 degrees north and south latitudes

Polar Cells

where polar air sinks and flows away from the poles downward meeting the ferrel cells at 60 degrees latitude

Coriolis effect

Causes moving air and water to turn left in the southern hemisphere and turn right in the northern hemisphere due to Earth's hemisphere., The apparent curving of the path of a moving object from an otherwise straight path due to the earth's rotation

doldrums

Calm, windless part of the ocean near the equato

trade winds

Prevailing winds that blow from east to west from 30 degrees latitude to the equator in both hemispheres

westerlies

prevailing winds that blow from west to east between 30 degrees & 60degrees latitude in the hemisphere.

Air pollutants

gases and particulate material added to the atmosphere that can affect climate or harm people or other organisms

Air pollution

Concentration of trace substances such as carbon monoxide, sulfur oxide, hydrocarbons, and solid particulates, at a greater level than occurs in average air.

outdoor air pollution

ambient air pollution, , pollution made of 6 principal air components: ozone, carbon monoxide, lead, nitrogen dioxide, sulfur dioxide, particulate matte

volcanic eruptions

The presence of aerosols in the air increase the amount of solar radiation that is reflected back into space. This causes the lower atmosphere to cool. Can cause climate change.

Aerosols

Can cause a haze in the atmosphere that reflects sunlight or increases cloud cover

Primary pollutants

pollutants that are put directly into the air by human or natural activity. Ie: soot and carbon monoxide,

Secondary pollutants

Air pollutants produced through reactions between primary pollutants and normal atmospheric compounds. ie: tropospheric ozone, sulfuric acid,

Clean Air Act 1970

Required EPA to develop and enforce regulations to protect the public from airborne contaminants; forced states to follow and make sure the laws for followed in relation to the EPA. States allowed to decide officials for enforcement.

Clean Air Act 1990

strengthened regulations for auto emissions, toxins, acid deposition, ozone depletion, while introducing market incentives, emissions trading

Carbon monoxide

CO , Colorless, odorless, poisonous gas produced by the combustion of of carbon or organic fuels.

sulfur dioxide

SO₂ , Created naturally by volcanoes. Human source is mainly from the burning of coal. Creates respiratory problems in humans and acid rain in the environment. colorless gas but pungent odor.

Nitrogen dioxide

NO₂ , a foul-smelling reddish brown gas, produced primarily by the incomplete combustion of fuel, that contributes to smog and acidic deposition

nitrogen oxides

(NOx) Major source is auto exhaust. Primary and secondary effects include acidification of lakes, respiratory irritation, leads to smog and ozone. Reduced using catalytic converters.

tropospheric ozone

ground level ozone; is considered bad because it is closer to the earth making it more likely for someone to breathe it in. It is also more dangerous because it is made up of particulate matter.

Particulate matter

a small discrete mass of solid or liquid matter that remains individually dispersed in gas or liquid emissions (usually considered to be an atmospheric pollutant)

Lead

Pb , A highly toxic metal that can damage the nervous system, blood, and kidneys, and can cause harm to the development of a children's intellectual abilities. Main source was leaded gasoline.

Volatile organic compounds (VOCs)

The fumes given off by organic chemicals such as paints, aerosol sprays, cleaner, disinfectants, new carpets, and glues.

three technologies that decrease air pollutants

baghouse filters, electrostatic precipitators and scrubbers

scrubbers

devices containing alkaline substances that precipitate out much of the sulfur dioxide from industrial plants.

toxic air pollutants

substances known to cause cancer, reproductive defects, or neurological, developmental, immune system, or respiratory problems.

examples of toxic air pollutants

hydrogen sulfide gas in swamps, smelting, sewage treatment and industrial processes. mercury, VOCs like benzene and methylene chloride,

industrial smog

Consists mostly of sulfur dioxide, suspended droplets of sulfuric acid (formed from some of the sulfur dioxide) and a variety of suspended solid particles and droplets.

photochemical smog

brown-air smog: , A brownish haze that is a mixture of ozone and other chemicals, formed when pollutants react with each other in the presence of sunlight

chlorofluorocarbons CFCs

widely regarded as harmful bc they are chemically unreactive to normal conditions. but over Antarctica they condense into tiny ice crystals that break down and produce chlorine which attacks and destroys the ozone

Montreal Protocol

(1987) phase-out of ozone depleting substances

Acid deposition

Caused by sulfuric and nitric acids resulting in lowered pH of surface waters (acid rain)

atmospheric deposition

Contaminants carried by air currents and precipitated into watersheds or directly onto surface waters, The wet or dry deposition on land of a wide variety of pollutants, including mercury, nitrates, organochlorines, and others.

indoor air pollution

Compounds that affect breathing that occur indoors. Examples: wood stove smoke, furnace emissions, formaldehyde, radon, household chemicals & Tobacco smoke.

cigarette smoke

leading cause of leading indoor pollutant. Can cause asthma, irritation of eyes, nose, and throat, and lung irritations and cancer.

radon

2nd leading cause of indoor air pollution., A colorless, odorless, radioactive gas. can cause lung cancer.