| Term | Definition |
| tropshere | the atmospheric layer closest to the earth's surface where nearly all weather occurs |
| stratosphere | the layer of the amosphere that extends upward from the troposhere to an alitutde of 50km and it contains the ozone layer |
| mesophere | the coldesst layer of the atmosphere located above the stratosphere |
| thermosphere | atmospheric layer above the mesosphere |
| greenhouse effect | the process by which the atmosphere traps some of the energy from the sun in the troposphere |
| transpiration | the evaporation of water through pores in a plants leaves |
| precipitation | any form of water that falls back to earht's surface from clouds; including rain, snow, sleet and hail |
| humidity | the quantity of water vapor in the atmosphere |
| relative humidity | ratio of the quantity of water vapor in the air to the maximum quantity of water vapor that can be present at that temperature |
| dew point | the temperature at which water vapor molecules start to form liquid water |
| barometric pressure | the pressure due to the weight of the atmosphere also called air pressure or atmospheric pressure |
| coriolis effect | the change in the direction of an objects path due to the earths rotation |
| air mass | a large body of air with uniform temperature and moisture content |
| front | the boundary between 2 air massess of different densities |
| isobar | a line drawn on a weather map connecting points of equal barometric or atmospheric pressure |
| climate | the general weather conditions over many years |
| topography | the surface features of the earth` |