Chapter 17: Atmosphere Science and Air Pollution

How does a primary pollutant differ from a secondary pollutant?

A primary pollutant, such as soot, is emitted into the atmosphere in a form that is directly harmful. A secondary pollutant is produced in the atmosphere by means of a chemical reaction occurring there. For example, the nitric acid in acid rain is produced by reaction of the primary pollutant NO2 and water vapor in the air

Name one characteristic of each of the four atmospheric layers.

-Troposphere: initial layer of atmosphere, extends from Earth's surface up to 11 miles up. This is the part of the atmosphere people live in. -Stratosphere: Up to 31 miles above Earth's surface. Some of Earth's gases become trapped, here. Not a lot of water vapor. -Mesosphere: Very little oxygen in this layer. It occurs at about 56 miles above Earth's surface. -Exosphere: is the outermost layer of the atmosphere, extending 6200 miles above the Earth. This is where satellites orbit the Earth.

Acid Deposition

A complex chemical and atmospheric phenomenon that occurs when emissions of sulfur and nitrogen compounds and other substances are transformed by chemical processes in the atmosphere and then deposited on earth in either wet or dry form. ... The dry forms are acidic gases or particulates.

High-pressure system

A high pressure system is a whirling mass of cool, dry air that generally brings fair weather and light winds. When viewed from above, winds spiral out of a high-pressure center in a clockwise rotation in the Northern Hemisphere. These bring sunny skies.

Low-pressure System

A low pressure system is a whirling mass of warm, moist air that generally brings stormy weather with strong winds. When viewed from above, winds spiral into a low-pressure center in a counterclockwise rotation in the Northern Hemisphere. A low pressure system is represented as a big, red L.

How do Hadley, ferrel, and polar cells help to determine long-term climatic patterns and the location of biomes?

Hadley, Ferrel, and polar cells are convection patterns in the atmosphere, driven by the sun's energy, that produce predictable bands of precipitation and wind direction over the globe. These factors in turn control the distribution of Earth's biomes.

How does solar energy influence weather and climate?

Solar energy heats air, causing pressure gradients that drive Earth's atmospheric circulation. This circulation distributes heat and moisture over Earth's surface (i.e., determines the main factors of climate).

How do weather and topography influence smog formation?

Major smog occurrences often are linked to heavy motor vehicle traffic, high temperatures, sunshine, and calm winds. Weather and geography affect the location and severity of smog. Because temperature regulates the length of time it takes for smog to form, smog can occur more quickly and be more severe on a hot, sunny day. When temperature inversions occur (that is, when warm air stays near the ground instead of rising) and the wind is calm, smog may remain trapped over a city for days. As traffic and other sources add more pollutants to the air, the smog gets worse. This situation occurs frequently in Salt Lake City, Utah.

Ozone Hole

a region of marked thinning of the ozone layer in high latitudes, chiefly in winter, attributed to the chemical action of chlorofluorcarbons and other atmospheric pollutants. The resulting increase in ultraviolet light at ground level gives rise to an increased risk of skin cancer.

Aerosols

a substance enclosed under pressure and able to be released as a fine spray, typically by means of a propellant gas

Photo-chemical Smog

air pollution produced by the action of sunlight on hydrocarbons, nitrogen oxides, and other pollutants.

Criteria Pollutants

carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide. Criteria pollutants are the only air pollutants with national air quality standards that define allowable concentrations of these substances in ambient air.

Sick-building Syndrome

is used to describe a situation in which the occupants of a building experience acute health- or comfort-related effects that seem to be linked directly to the time spent in the building. No specific illness or cause can be identified.

Atmospheric Pressure

the pressure exerted by the weight of the atmosphere, which at sea level has a mean value of 101,325 pascals (roughly 14.6959 pounds per square inch).

Relative Humidity

the amount of water vapor present in air expressed as a percentage of the amount needed for saturation at the same temperature.

Industrial Smog

the black-brown colored haze that is in the air that can be seen over some cities. It is mostly visible in the summer. The smog itself is composed of sulfur dioxide, small amounts of sulfuric acid, and suspended particles from the burning of coal and oil

Cold Front

the boundary of an advancing mass of cold air, in particular the trailing edge of the warm sector of a low-pressure system.

Warm Front

the boundary of an advancing mass of warm air, in particular the leading edge of the warm sector of a low-pressure system.

Stratosphere

the layer of the earth's atmosphere above the troposphere, extending to about 32 miles (50 km) above the earth's surface (the lower boundary of the mesosphere)

Troposphere

the lowest region of the atmosphere, extending from the earth's surface to a height of about 3.7-6.2 miles (6-10 km), which is the lower boundary of the stratosphere.

Weather

the state of the atmosphere at a place and time as regards heat, dryness, sunshine, wind, rain, etc.

Climate

the weather conditions prevailing in an area in general or over a long period

Ozone-depleting substances

those substances which deplete the ozone layer and are widely used in refrigerators, air conditioners, fire extinguishers, in dry cleaning, as solvents for cleaning, electronic equipment and as agricultural fumigants.

Secondary Pollutants

not directly emitted as such, but forms when other pollutants (primary pollutants) react in the atmosphere.

Air Pollutants

Any substance in air that could, in high enough concentration, harm animals, humans, vegetation, and/or materials. Such pollutants may be present as solid particles, liquid droplets, or gases.

Name three impacts of acid deposition.

-As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes. - In areas such as mountainous parts of the Northeast United States, the soil is thin and lacks the ability to adequately neutralize the acid in the rain water. As a result, these areas are particularly vulnerable and the acid and aluminum can accumulate in the soil, streams, or lakes. -nitrogen pollution in our coastal waters is partially responsible for declining fish and shellfish populations in some areas.

Name 5 common sources of indoor pollution. For each, describe one way to reduce one's exposure to this source.

1. Radon- testing for radon is relatively inexpensive and easy to do using readily available radon testing kits. 2. Secondhand Smoke- Do not smoke inside the home 3. Mold and Mildew- Keep your house free of excess moisture 4. Carbon Monoxide- Carbon monoxide detectors are easily available 5. VOCs- store them outside the home whenever possible

Name one health rise from toxic air pollutants.

Acidic deposition, an example of a secondary pollutant, can occur far from the source of its precursor pollutants because of the long-range atmospheric transport that occurs while the atmospheric chemical reactions are occurring

What has happened with our emissions of major pollutants in recent decades?

CFCs split O3 to produce O2. Because CFCs persist in the atmosphere for years, are mixed all over the world regardless of their source, and destroy UV-protective stratospheric ozone, they are considered a long-term international problem. Many nations of the world came together to create the Montreal Protocol, which limited the production of CFCs and similar chemicals internationally.

Why is ozone depletion considered a long-term international problem? What was done to address this problem?

Increased uv radiation can damage phytoplankton which remove co2 from the atmosphere which affects climate change. Ozone depletion will lead to large amounts of temperature rises. The Clean Air Act (Title VI) limits pollution.

How do CFCs deplete stratospheric ozone?

Once in the atmosphere, CFCs drift slowly upward to the stratosphere, where they are broken up by ultraviolet radiation, releasing the chlorine that catalytically destroys ozone. In the graphic below, the destructive cycle of a chlorine atom is shown. UV radiation breaks off a chlorine atom from a CFC molecule.

Clean Air Act of 1970/1990

The Clean Air Act of 1970 (1970 CAA) authorized the development of comprehensive federal and state regulations to limit emissions from both stationary (industrial) sources and mobile sources.

How do inversions contribute to severe smog episodes like the ones in London and Donora, PA?

The London smog event of 1952 was caused by the exhausts of coal-burning power plants and home fireplaces/furnaces being trapped in a layer of colder, denser air near the surface— a so-called thermal inversion. The 1948 Donora smog was a historic air inversion that resulted in a wall of smog that killed 20 people and sickened 7,000 more in Donora, Pennsylvania.

Montreal Protocol

The Montreal Protocol on Substances that Deplete the Ozone Layer (a protocol to the Vienna Convention for the Protection of the Ozone Layer) is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion.

Where is the "ozone layer" located?

The Ozone layer is actually located in the stratosphere in a region that is 10 to 50 km above the Earth.

Ferrel Cells/Polar Cells

The global circulation can be described as the world-wide system of winds by which the necessary transport of heat from tropical to polar latitudes is accomplished. In each hemisphere there are three cells (Hadley cell, Ferrel cell and Polar cell) in which air circulates through the entire depth of the troposphere.

Convective Circulation

The motion of warm material that rises, cools off, and sinks again, producing a continuous circulation of material and transfer of heat.

Outdoor Air Pollution

The presence in the air of substances suh as carbon monoxide (CO), NO2, ozone, particulate matter, and SO2, which are byproducts of human activities, and which have an adverse effect on health.

How and why is stratospheric ozone beneficial for people, whereas trophospheric ozone is harmful?

Upper atmosphere Ozone shields us from harmful UV rays. However Ozone is toxic to life, so when its present in the troposphere we can breathe its poison.

Carbon Monoxide

a colorless, odorless toxic flammable gas formed by incomplete combustion of carbon.

Hadley Cells

a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes, typically about 30° north or south.

Ozone Layer

a layer in the earth's stratosphere at an altitude of about 6.2 miles (10 km) containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun.

Primary Pollutants

an air pollutant emitted directly from a source.

Scrubber

an apparatus using water or a solution for purifying gases or vapors.

Coriolis Effect

an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force ) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern and is important in the formation of cyclonic weather systems

Temperature/Thermal Inversion

an inversion is a deviation from the normal change of an atmospheric property with altitude. It almost always refers to a "temperature inversion", i.e. an increase in temperature with height, or to the layer ("inversion layer") within which such an increase occurs.

Chloroflorocarbons

any of a class of compounds of carbon, hydrogen, chlorine, and fluorine, typically gases used in refrigerants and aerosol propellants. They are harmful to the ozone layer in the earth's atmosphere owing to the release of chlorine atoms upon exposure to ultraviolet radiation.

Acid Rain

rainfall made sufficiently acidic by atmospheric pollution that it causes environmental harm, typically to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulfur and nitrogen oxides, which combine with atmospheric water to form acids.