ENVIRSC 1C03 Exam Definitions

atmosphere

thin blue region along the edge of the Earth; a mixture of gas molecules, small suspended solid/liquid particles, and falling precipitation

hydrosphere

liquid realm of the Earth (fresh, salt, frozen)

cryosphere

frozen part of Earth

lithosphere

encompasses the solid Earth

biosphere

encompasses all life on Earth; economy, culture, technology, etc.

environmental science

the study of how the natural world works, how humans affect their environment, and how the environment affects humans

variable gases

concentrations vary from place to place/time to time

aerosols

any solid and or/liquid particles, other than water, that exist in the atmosphere

environmental lapse rate

the rate of temperature decrease with increasing height in the troposphere

troposphere

the lowest layer of Earth's atmosphere

stratosphere

the second layer of the atmosphere and contains the ozone layer

mesosphere

the layer of Earth's atmosphere immediately above the stratosphere; coldest layer

thermosphere

The uppermost layer of the atmosphere, in which temperature increases as altitude increases; merges with interplanetary space

ionosphere

electrified region in the upper atmosphere where large concentrations of ions/electrons exist

climate

average conditions of the atmosphere in a region

microclimate

near/on the ground surface

mesoclimate

small area of Earth's surface

macroclimate

climate of states/countries/provinces

global climate

the mean climatic conditions over the surface of the entire Earth

weather

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

air density

how closely packed the air molecules are

pollution

human-caused addition of any material or heat energy in amounts that cause undesirable alterations to the environment

primary pollutants

direct products of either combustion of evaporation

secondary pollutants

products of interactions of primary pollutants with other substances in the atmosphere and light from the sun

point source

one controllable site

fugitive source

an open area exposed to wind action

area source

a well-defined source within which there are several sources of air pollutants

mobile source

move place-to-place while emitting pollutants

ozone hole

a thinning of stratospheric ozone that occurs over the poles during the spring

chlorofluorocarbons

chlorine compounds that are the main cause of ozone depletion

radiant energy

energy transferred from the sun to Earth

rayleigh scattering

scattering of light caused by atmospheric particles smaller than the wavelength being scattered

transmission

when solar energy passes through the air unimpeded

insolation

describes incoming solar radiation

albedo

the percentage of incoming sunlight reflected from a surface

conduction

the direct transfer of heat from one substance to another substance that it is touching

sensible energy

the portion of the internal energy of a system associated with the kinetic energies of the molecules

convection

vertical circulations carry warmer surface air aloft, warming the air away from the surface

latent heat

the heat required to convert a solid into a liquid or vapor, or a liquid into a vapor, without change of temperature

meteorology

the scientific study of the atmosphere and the phenomena that we usually refer to as weather

wind

result of horizontal differences in air pressure

atmospheric pressure

the force per unit area that is exerted on a surface by the weight of the atmosphere

anticyclones

high pressure centers of dry air

mid-latitude cyclones

low pressure systems that develop where air masses from north and south meet in mid-latitude; weathers on fronts

hydrostatic balance

balance between upward push of air towards space and downward force of gravity

convergence

the net flow of air into a region cause air to be squeezed into a smaller space, resulting in an air column exerting more force on the surface

divergence

when there is a net outflow of air in a region

industrial smog

combination of combusted gases and fog

photochemical smog

gases released by car exhaust that react with sunlight

thermal inversions

a warm, lighter layer of air exists at a high altitude over the colder air at ground surface

air quality index

a scale that ranks levels of ozone and other air pollutants; an indicator of air quality

air quality health index

a numerical scale used to indicate overall air quality based on concentrations of air pollutants including ozone, particulate matter, and nitrogen dioxide

blackbodies

have a rate of radiation that would be expected from Stefan-Boltzmann equation

greybodies

not perfect radiators so that their rates of radiation cannot be perfectly calculated form Stefan-Boltzmann equation

june solstice

occurs when the direct rays of the sun fall along the Tropic of Cancer; longest day in Northern hemisphere

december solstice

northern hemisphere tilts away from sun and has shortest day and longest night; southern hemisphere tilts toward sun and has longest day and shortest night

vernal equinox

the day of the year that marks the beginning of spring in the northern hemisphere

autumnal equinox

the day of the year that marks the beginning of fall in the Northern hemisphere

tropical zones

home of world's driest deserts

midlatitude zones

sun's height in the sky varies widely throughout the year

subarctic zone

largely covered by evergreen forests

maritime climates

A climate moderated by proximity to oceans or large seas. It is usually cool, cloudy, and wet and lacks the temperature extremes of continental climates.

continental climates

Areas that are too far inland to be warmed or cooled by the ocean. These areas have much more extreme temperatures where winters are cold and summers are warm or hot.

heat capacity

a measure of the ability of a material to absorb heat

anthropogenic climate change

alterations to climate resulting from human impact

urban heat island

city much warmer than surrounding countryside

specific humidity

actual quantity of water vapour in air

saturation specific humidity

maximum amount of water that an air parcel can contain at any given time

relative humidity

the amount of water vapour present in air compared to the maximum water vapour at that temperature

dry adiabatic lapse rate

the rate at which the temperature of a parcel of dry air decreases as the parcel is lifted in the atmosphere.

moist adiabatic lapse rate

rate at which rising air is cooled by expansion when condensation is occurring

nimbostratus clouds

thicker layer than stratus clouds that completely block out the sun cause steady rain and snow; low liquid water clouds

cumulonimbus clouds

large clouds that often produce thunderstorms; high liquid water clouds

saturation

an equilibrium condition in which the rate at which molecules evaporate is balanced by the rate at which they condense

dew point

temperature at which saturation occurs in the air; the temperature at which water vapour starts to condense

adiabatic process

occurs without transfer of heat or mass of substances

level of free convection

altitude in the atmosphere where the temperature of the environment in lower than the rising air parcel

orographic uplift

occurs when a mass of air is deflected over/around a terrain

fog

surface cloud when air cools to the dew point, has moisture added to it, or when cooler air is mixed with warm moist air

radiation fog

tends to form on clear, relatively calm nights, when cool moist surface are is overlain by drier air, and rapid radiative cooling occurs

advection fog

forms when warm moist air moves across a cold surface

upslope fog

forms as moist air slowly rises, cools and condenses over elevated terrain or an orographic barrier

evaporation fog

forms over water bodies as water vapor comes in contact with the cold air above

precipitation

any form of water that falls from the clouds to the ground surface

accretion

how ice crystals grow

aggregation

process of ice crystals colliding and sticking together

permafrost

permanently frozen ground

snowline

the point above which snow and ice cover the ground throughout the year

acidification

increase in concentration of hydrogen ions in water and/or soil

water table

underground boundary between the soil surface and the area where the ground is saturated with water

capillary water

held in micropores in the soil, returns the atmosphere by evaporation/transpiration

gravitational water

water held at low pressures that will drain freely down through and out of the soil in response to gravity

hygroscopic water

soil water held so tightly by sediment grains that it is unavailable for plant use

effluent

liquid waste or sewage discharged into a river or the sea; gaining river

influent

losing river; discharge water by percolation

watershed

the land area that supplies water to a river system/drains water to a common point

Pacific Ocean Garbage Patch

a gyre of marine debris particles in the central North Pacific Ocean

intertropical convergence zone (ITCZ)

the area of the Earth that receives the most intense sunlight, where the ascending branches of the two Hadley cells converge

Hadley cells

a pattern of atmospheric circulation in which warm air rises near the equator, cools as it travels poleward at high altitude, sinks as cold air, and warms as it travels equatorward

topsoil

mixture of humus, clay, and other minerals that forms the crumbly, topmost layer of soil