| A | B |
|---|
| stratosphere | the of the atmosphere above the troposphere; extends 11 to 50 km above sea level |
| ozone layer | the concentration of ozone in the stratosphere. |
| mesosphere | the later of the atmosphere above the stratosphere; extends 50 to 80 km above sea level. |
| thermosphere | the top layer of the atmosphere; extends from 80 km above sea level infinitely into space. |
| atmosphere | the thin layer of gases that surrounds Earth. |
| relative humidity | the ratio of water vapor in the air to the maxmum amount of water vapor the air culd hold at that temperature; expressed as a percentage. |
| air pressure | the force exerted by air on the area below it; also called atmospheric pressure. |
| troposphere | the lowest layer of the atmosphere; extends 0 to 11 km above sea level. |
| radiation | the transfer of energy through space |
| conduction | the transfer of heat directly between two objects that ae in contact with each other. |
| convection | the transfer of heat in a fluid as warm parts of the fluid rise from the eat source and expand. |
| convection currents | the movement in a fluisd as warm parts of the fluid rise ad cool parts sink |
| air mass | a large body of air in wich properties sch as temperature, pressure, and humidity are similar |
| front | the boundary between air masses that diffe in temperaure and moisture |
| air pollution | the releas of damaging materials into the atmosphere. |
| emission | a substanc that is released into the atmoshere; the cause of air pollution. |
| fossil fuel | a carbon-containing fuel formed over millions of years from the remains of living things. |
| primary air pollutant | a pollutant released directly into the troposhpere; can cause damage itself or react with other substances to cause damage |
| secondary air pollutant | a harmful substance produced when a primary pollutant reacts with other sbstances. |
| smog | an unhealthy mixture of air pollutants that can fom over cities and nearby areas |
| temperature inversion | the condition in te troposhere in which a layer of cooler air lies beneath a layer of warmer air; also called thermal inversion |
| acid deposition | water vapor containing acids that falls to the ground as rain, snow, sleet, or hail. |
| Clean Air Act | an act that ets strict standards for air quality and strengthens the governments ability to enforce regulations. |
| catalytic converter | a device in a motor vehicle that reduces the amount of pollutants in emissions. |
| scrubber | a device that removes pollutants or changes them chemically before they leave factory smokestacks. |
| ozone hole | the area of lowered ozone concentration over Antarctica. |
| chloroflourocarbon (CFC) | a chemical compound containing chlorine, florine, and carbon, developed fo use in refrigeration and spray-can propellants. |
| Montreal Protocol | the treaty that limits the production of chloruflourocarbons. |
