Question | Answer |
water cycle | The continuous movement of Earth’s water from the oceans and freshwater sources to the atmosphere and eventually back to the oceans. |
evaporation | The process that occurs when heat energy from the sun causes water on the surface of the Earth to change phase to water vapor. |
transpiration | The process that occurs when plants give off water vapor that enters the atmosphere. |
condensation | The process that occurs when water vapor in the atmosphere cools and changes back into liquid water and forms clouds. |
precipitation | The process that occurs when water returns to the Earth in the form of rain, snow, sleet, or hail. |
surface runoff | The process that occurs when precipitation falls on land, the soil becomes saturated and the water flows along the surface into a body of water. |
infiltration | The process that occurs when precipitation falls on land and the water soaks into the soil. |
permeability | Describes how well water can move through a soil material. |
groundwater | Water located beneath the ground surface in soil pore spaces. |
pore space | The space between particles of soil. |
porosity | A measure of the amount of pore space in soil material. |
aquifer | An underground layer of permeable rock or materials (gravel, sand, sandstone, or cracked limestone). |
watershed | A land area in which surface runoff drains into a river or a system of rivers and streams. |
air pressure | A measure of the force of air pressing down on the Earth’s surface. |
barometer | A weather instrument used to measure air pressure. |
relative humidity | The percentage of moisture that air holds relative to the amount of moisture it could hold. |
air mass | A large body of air with uniform properties throughout (temperature, humidity, and pressure). |
cold front | A weather front that forms when a cold air mass meets and pushes under a warm air mass. Violent storms are associated with this type of front and fair, cool weather usually follows. |
warm front | A weather front that forms when a mass of warm air overtakes a cold air mass and moves over it. Rain and showers usually accompany this type of front and hot, humid weather usually follows. |
stationary front | A weather front that forms when a warm air mass meets a cold air mass and no movement occurs. This type of front can cause weather conditions that can last for days. |
occluded front | A weather front that forms when a cold front overtakes a warm front, pushing the warm air upwards until cold air meets cool air. Less extreme weather occurs during this type of front. |
weather | The daily condition of the Earth’s atmosphere. |
isotherm | A line on a weather map that connects locations with the same temperature. |
isobar | A line on a weather map that connects locations with the same air pressure. |
climate | The general conditions of temperature and precipitation for an area over a long period of time. |
absorption | The process of groundwater being drawn up by plant roots. |