12. Effects of Water Vapour in the Atmosphere Flashcards
Term
Definition
Absolute Humidity
The mass of water vapor present in a given volume of air.
Dew Point
The temperature at which air becomes saturated with moisture and condensation begins.
Evaporation
The process of turning liquid water into vapor, adding moisture to the air.
Sublimation
The transition of water directly from a solid (ice) state to vapor, bypassing the liquid phase.
Condensation
The process where water vapor becomes liquid; it is crucial in cloud formation and precipitation.
Saturation
A condition where air contains the maximum amount of water vapor it can hold at a given temperature and pressure.
Vapor Pressure
The pressure exerted by water vapor present in the air.
Relative Humidity
The amount of moisture in the air compared to what the air can hold at that temperature, expressed as a percentage.
Hygrometer
An instrument used to measure the moisture content or the humidity of the air.
Fog
A thick cloud of tiny water droplets suspended in the atmosphere at or near the Earth’s surface that impedes visibility.
Mist
Finer than fog, consisting of tiny water droplets suspended in the air, typically reducing visibility less severely than fog.
Clouds
A visible mass of condensed water vapor floating in the atmosphere, typically high above the ground.
Precipitation
Any form of water - liquid or solid - that falls from clouds and reaches the ground.
Rain
Liquid water in the form of droplets that have condensed from atmospheric water vapor and then become heavy enough to fall under gravity.
Snow
Atmospheric water vapor frozen into ice crystals and falling in light white flakes or lying on the ground as a white layer.
Sleet
A form of precipitation consisting of ice pellets, often mixed with rain or snow.
Hail
Pellets of frozen rain which fall in showers from cumulonimbus clouds.
Transpiration
The process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere.
Water Cycle
The continuous process by which water is circulated throughout the Earth and its atmosphere.
Evapotranspiration
The sum of evaporation and plant transpiration from the Earth’s land and ocean surface to the atmosphere.
Humidity
The concentration of water vapor present in the air.
Wet-Bulb Temperature
The lowest temperature that can be reached by evaporating water into the air at constant pressure.
Psychrometer
An instrument used to measure the relative humidity and dew point in the atmosphere.
