| A | B |
|---|
| weather | general condition of the atmosphere at a particular time & place |
| atmosphere | the thick blanket of gases surrounding Earth |
| ozone | form of atmospheric oxygen that has three atoms of oxygen per molecule |
| atmospheric pressure | weight of the air pressing on a given surface area |
| troposphere | the atmospheric layer closest to Earth's surface |
| mesosphere | the layer of the atmosphere that extends upward from the stratosphere to an altitude of about 80 km |
| stratosphere | the layer of the atmosphere that extends upward from the troposphere to an altitude of 50 km |
| thermosphere | the atmosphere layer above the mesosphere |
| ionosphere | the lower region of the thermosphere, at an altitude of 80-550 km |
| exosphere | the layer of the atmosphere above the ionosphere that merges with interplanetary space |
| rayleigh scattering | reflecting & bending of light rays in the atmosphere that results in making the sky appear blue |
| greenhouse effect | the process by which the atmosphere traps infrared rays over Earth's surface |
| air pollutant | any substance in the atmosphere that is harmful to living organisms or to other materials |
| acid rain | rain formed by a combination of pollutants & water in the atmosphere |
| temperature inversion | atmospheric condition in which warm air traps polluted, cooler air near Earth's surface |
| smog | air pollutant fomred from a mixture of dust & chemicals |
| coriolis effect | the deflection of wind & ocean currents caused by Earth's rotation |
| wind cells | looping pattern of flowing air |
| doldrums | narrow zone of low air pressure at the equator characterized by weak & unpredictable winds |
| trade winds | global winds moving toward the equator between 30 & 0 degrees of latitude |
| horse latitudes | subtropical high; belt of high air pressure around 30 degrees of latitude |
| prevailing westerlies | global winds located between 40 & 60 degrees of latitude that blow from the SW in the northern hemisphere |
| polar easterlies | weak global winds located north of 65 degrees north latitude that blows away from the poles |
| jet stream | bands of high speed, high altitude westerly winds |
| land breeze | warm, gentle wind that flows from the land to the water |
| sea breeze | cool, gentle wind that flows from the water to the land |
| valley breeze | gentle wind that flows up mountain slopes during the day |
| mountain breeze | gentle wind that flows down mountain slopes at night |
| beaufort scale | wind speed scale |
| water vapor | gaseous form of water found in the atmosphere |
| evaporation | process by which liquid water changes to water vapor |
| condensation | process by which water vapor changes to liquid water |
| sublimation | process by which a solid changes directly into a vapor or a vapor changes directly into a solid |
| humidity | amount of water vapor in the atmosphere |
| psychrometer | instrument used to measure relative humidity |
| relative humidity | ratio of the amount of water vapor in the air to the amount of water vapor the air can hold when saturated |
| dew point | temperature to which air must be cooled to become saturated |
| condensation nuclei | solid particles in the atmosphere, such as ice & dust, that provide the surfaces on which water vapor condenses |
| convective cooling | decrease in the temperature of a mass of air that results as it rises & expands |
| adiabatic | describing a change in temperature resulting from the expansion or compression of air |
| advective cooling | decrease in the temperature of a mass of air that results as it moves over a cold surface |
| stratus cloud | cloud with a sheetlike form that is the lowest cloud in the sky |
| cumulus cloud | thick, billowy cloud that forms above stratus clouds & below cirrus clouds |
| cirrus cloud | feathery cloud composed of ice crystals that has the highest altitude of any cloud in the sky |
| nimbus | term used to describe clouds containing rain |
| radiation fog | condensation of water vapor that results from the cooling of air that is in contact with the ground |
| advection fog | condensation of water vapor that results from the cooling of warm, moist air as it moves across a cold surface |
| steam fog | condensation of water vapor that results when cool air moves over warm water |
| upslope fog | condensation of water vapor that results from the lifting & adiabatic cooling of air rising up a slope of land |
