Meteopedia — Weather glossary
Weather encyclopedia with 342 terms
Browse detailed definitions of atmospheric phenomena, cloud types, measurement instruments, regional winds, meteorological scales, climatology and more.
A
Adiabatic lapse rate
Rate at which air changes temperature as it rises or descends without exchanging heat with its surroundings: ~10 °C/km for dry air and ~6 °C/km for saturated air.
GeneralAdvection
Horizontal transport of heat, moisture, or other atmospheric properties by the wind, a key process in weather evolution.
GeneralAir mass
Extensive volume of air with uniform temperature and humidity characteristics acquired in its source region.
GeneralAtmosphere
Gaseous layer surrounding the Earth, composed mainly of nitrogen (78%) and oxygen (21%), divided into concentric layers by their thermal profile.
GeneralAtmospheric pressure
Force exerted by the weight of the air column on the Earth's surface, measured in hectopascals (hPa).
GeneralAtmospheric stability
Tendency of the atmosphere to resist or enhance vertical air motion: a stable atmosphere suppresses convection, an unstable one promotes it.
GeneralC
CAPE
Convective Available Potential Energy: a measure of the energy a rising air parcel can release, used to estimate the potential for severe thunderstorms.
GeneralConvection
Vertical transport of heat and moisture in the atmosphere through the rise of warm air and descent of cold air, driving cumuliform clouds and thunderstorms.
GeneralCoriolis effect
Apparent deflection of moving objects on Earth caused by the planet's rotation: to the right in the Northern Hemisphere and to the left in the Southern.
GeneralI
P
Planetary boundary layer
Lowest layer of the atmosphere (0-2 km) directly influenced by Earth's surface, key for pollutant dispersion and local weather.
GeneralPolar vortex
Mass of cold, low-pressure air spinning over each pole in the stratosphere and troposphere, whose weakening can trigger extreme cold spells at mid-latitudes.
GeneralPressure gradient
Difference in atmospheric pressure between two points divided by the distance between them, the primary driving force of wind.
GeneralS
T
Thermosphere
Atmospheric layer between 85 and 600 km altitude where temperature rises rapidly with height due to UV radiation absorption, home to auroras and the ISS orbit.
GeneralTropopause
The boundary between the troposphere and stratosphere, where temperature stops decreasing with altitude.
GeneralTroposphere
Lowest layer of the atmosphere (0–12 km) where all weather phenomena occur.
GeneralW
Water cycle
Continuous circulation of water between the atmosphere, land surface, and oceans through evaporation, condensation, and precipitation.
GeneralWMO
World Meteorological Organization. United Nations agency coordinating international cooperation in meteorology, climatology, hydrology, and related geophysical sciences.
General