Ch. 13 - Atmospheric Science and Air Pollution

Question 1

troposphere

Answer 1

The lowest layer of the atmosphere; it extends to 11 km above sea level.

Question 2

stratosphere

Answer 2

The layer of the atmosphere above the troposphere and below the mesosphere; it extends from 11 km to 50 km above sea level.

Question 3

ozone (O3)

Answer 3

A molecule consisting of three atoms of oxygen. Ozone in the stratosphere performs the important function of absorbing ultraviolet radiation, but occurring in the troposphere it is an air pollutant.

Question 4

ozone layer

Answer 4

A portion of the stratosphere, roughly 17-30 km above sea level, that contains most of the ozone in the atmosphere.

Question 5

mesosphere

Answer 5

The atmospheric layer above the stratosphere, extending 50-80 km above sea level. (The term mesosphere also applies to part of Earth’s mantle).

Question 6

thermosphere

Answer 6

The atmosphere’s top layer, extending upward to an altitude of 500 km.

Question 7

microclimate

Answer 7

Variations in weather and climate that occur on an extremely local scale, such as from one side of a hill to the other.

Question 8

atmospheric pressure

Answer 8

The weight per unit area produced by a column of air.

Question 9

relative humidity

Answer 9

The ratio of the water vapour contained in a given volume of air to the maximum amount the air could contain, for a given temperature.

Question 10

air mass

Answer 10

A large volume of air that is internally uniform in temperature, relative humidity, and density.

Question 11

weather

Answer 11

The local physical properties of the troposphere, such as temperature, pressure, humidity, cloudiness, and wind, over relatively short time periods.

Question 12

climate

Answer 12

The pattern of atmospheric conditions found across large geographical regions over long periods of time.

Question 13

front

Answer 13

The boundary between air masses that differ in temperature and moisture (and therefore density).

Question 14

warm front

Answer 14

The boundary where a mass of warm air displaces a mass of colder air.

Question 15

cold front

Answer 15

The boundary where a mass of cold air displaces a mass of warmer air.

Question 16

high-pressure system

Answer 16

An air mass with elevated atmospheric pressure, containing air that descends, typically bringing fair weather.

Question 17

low-pressure system

Answer 17

An air mass in which the air moves toward the low atmospheric pressure at the centre of the system and spirals upward, typically, bringing clouds and precipitation.

Question 18

thermal inversion

Answer 18

A departure from the normal temperature distribution in the atmosphere, in which a pocket of relatively cold air occurs near the ground, with warmer air above it. The cold air, denser than the air above it, traps pollutants near the ground and causes a buildup of smog.

Question 19

urban heat island effect

Answer 19

A phenomenon in which cities are generally several degrees warmer than surrounding suburbs and rural areas, due to tall buildings that interfere with convective cooling, paved surfaces that absorb heat, and concentrated activities that generate waste heat. The urban heat island effect can contribute to the development of dust domes.

Question 20

dust dome

Answer 20

A phenomenon in which smog and particulate air pollution become trapped in a layer overlying an urban centre. Can be exacerbated by the urban heat island effect.

Question 21

Hadley cell

Answer 21

One of a pair of cells of convective circulation between the equator and 30 degrees north and south latitude that influence global climate patterns.

Question 22

Ferrel cell

Answer 22

One of a pair of cells of convective circulation between 30 and 60 degrees north and south latitude that influence global climate patterns.

Question 23

polar cell

Answer 23

One of a pair of cells of convective circulation between the poles and 60 degrees north and south latitudes that influence global climate patterns.

Question 24

Coriolis effect

Answer 24

The apparent deflection of north-south air currents to a partly east-west direction, caused by the Coriolis force, which results from the faster spin of regions near the equator than of regions near the poles as a result of Earth’s rotation.

Question 25

trade winds

Answer 25

Prevailing winds between the equator and 30 degrees latitude that blow from east to west.

Question 26

air pollution

Answer 26

The act of contaminating the air, or the condition of being contaminated by air pollutants.

Question 27

aerosols

Answer 27

Very fine liquid droplets or solid particles aloft in the atmosphere.

Question 28

primary pollutant

Answer 28

A hazardous substance, such as soot or carbon monoxide, that is emitted into the troposphere in a form that is directly harmful.

Question 29

secondary pollutant

Answer 29

A hazardous substance produced through the reaction of substances added to the atmosphere with chemicals normally found in the atmosphere.

Question 30

criteria air contaminants (CACs) (or criteria pollutants)

Answer 30

Six air pollutants - carbon monoxide, sulphur dioxide, nitrogen dioxide, tropospheric ozone, particulate matter, and lead - for which maximum allowable concentrations have been established for ambient outdoor air because of the threats they pose to human health.

Question 31

sulphur dioxide (SO2)

Answer 31

A criteria air contaminant and a common by-product of the burning of fossil fuels, especially coal.

Question 32

sulphur oxides (SOx or SOX)

Answer 32

Various sulphur-based gaseous compounds, including SO2 and SO3, which commonly result from industrial processes involving combustion, especially of coal.

Question 33

nitrogen dioxide (NO2):

Answer 33

A criteria air contaminant and a common by-product of internal combustion engines.

Question 34

nitrous oxides (NOx or NOX)

Answer 34

Various nitrogen-based gaseous compounds, including NO2 and NO3, which commonly result from industrial processes involving combustion, especially in internal combustion engines.

Question 35

particulate matter (PM)

Answer 35

Solid and (sometimes) liquid and colloidal particles (aerosols) small enough to be suspended in the atmosphere and able to damage respiratory tissues when inhaled. Includes primary pollutants such as dust and soot, as well as secondary pollutants such as sulphates and nitrates. A criteria air contaminant; abbreviated PM and categorized by particle size (e.g., PM2.5, particles less than 2.5)

Question 36

volatile organic compounds (VOC)

Answer 36

One of a large group of potentially harmful organic chemicals used in industrial processes.

Question 37

carbon monoxide (CO)

Answer 37

A colourless, odourless gas produced primarily by the incomplete combustion of fuel. A criteria air pollutant.

Question 38

ammonia (NH3)

Answer 38

A colourless gas with a pungent smell; an important precursor component of terrestrial plant nutrients.

Question 39

tropospheric ozone:

Answer 39

Ground-level ozone, an air pollutant and a component of smog.

Question 40

persistent

Answer 40

Refers to a chemical that does not break down, degrade, or decompose easily, and that consequently may have a long residence time in a given environmental reservoir.

Question 41

heavy metals

Answer 41

A metallic element with high density or atomic mass. Some of these, such as lead, mercury, and arsenic, are neurotoxins and thus are of concern from a public health and environmental perspective.

Question 42

toxic air pollutant

Answer 42

Air pollutant that is known to cause cancer, reproductive defects, or neurological, developmental, immune system, or respiratory problems in humans, and/or to cause substantial ecological harm by affecting the health of nonhuman animals and plants.

Question 43

transboundary pollution

Answer 43

Pollution that is transported from its source, by air, water, or some other mechanism, across a national boundary.

Question 44

scrubber

Answer 44

Technology used to chemically treat gases produced in combustion to remove hazardous components and neutralize acidic gases, such as sulphur dioxide and hydrochloric acid, turning them into water and salt, in order to reduce smokestack emissions.

Question 45

industrial smog

Answer 45

Grey-air among caused by the incomplete combustion of coal or oil when burned.

Question 46

photochemical smog

Answer 46

Brown-air among caused by light-driven reactions of primary pollutants with normal atmospheric compounds that produce a mix of over 100 different chemicals, ground-level ozone often being the most abundant among them.

Question 47

airshed

Answer 47

The geographical area associated with a particular air mass.

Question 48

acidic deposition

Answer 48

The deposition of acidic or acid-forming pollutants from the atmosphere onto Earth’s surface by the precipitation of unusually acidic rain, snow, or hail, fog, or settling of dry particles.

Question 49

acid drainage (or acid mine drainage)

Answer 49

A process in which sulphide minerals in newly exposed rock surfaces react with oxygen and rain water to produce sulphuric acid, which causes chemical runoff as it leaches metals from the rocks. Acid drainage can be a natural phenomenon, but mining can greatly accelerate it by exposing many new rock surfaces.

Question 50

acid mine drainage (or AMD):

Answer 50

Acidic precipitation deposited in the form of rain.

Question 51

atmospheric deposition

Answer 51

The wet or dry deposition on land of a wide variety of pollutants, including mercury, nitrates, organochlorides, and others. Acidic deposition is one type of atmospheric deposition.

Question 52

chlorofluorocarbon (CFC)

Answer 52

One of a group of human-made organic compounds derived from simple hydrocarbons, such as ethane and methane, in which hydrogen atoms are replaced by halide elements such as chlorine, bromine, or fluorine. CFCs deplete the protective ozone layer in the stratosphere.

Question 53

ozone hole

Answer 53

Term popularly used to describe the annual depletion of the stratospheric ozone layer as a result of chemical interactions with anthropogenic pollutants such as chlorofluorocarbons.

Question 54

Montreal Protocol

Answer 54

International treaty ratified in 1987, in which the (now 197) signatory nations agreed to restrict production of chlorofluorocarbons (CFCs) in order to forestall stratospheric ozone depletion.

Question 55

sick-building syndrome

Answer 55

An illness produced by indoor air pollution of which the specific cause is not identifiable.