Glossary of Meteorological Terms
Anticyclone-Area of high pressure in which the winds blow clockwise in the Northern Hemisphere.
Anticyclonic - Turning clockwise or opposite the direction of the earth's rotation.
Atmospheric Boundary Layer (Planetary Boundary Layer)-The part of the troposphere directly influenced by the earth's surface and responds to surface forcings with a timescale of one hour or less. (Stull, 1988)*.
Atmospheric models - Simulations of the atmosphere by mathematical equations or physical models.
Bermuda (subtropical) high- A semipermanent high located off the east coast of the U.S.
Cold Front- A transition zone where cold air moves in and replaces warm air.
Cumulonimbus- A thunderstorm cloud.
Cyclonic - Turning counterclockwise or in the same direction as the earth's rotation.
Dew- Water condensed on the ground or objects because the air has dropped below the dewpoint temperature.
Dewpoint- The temperature to which air must be cooled for water to condense (water vapor to liquid).
Fog - A cloud located at the ground.
Front - boundary between two differing air masses.
Hectapaschal - A unit of measure atmospheric pressure. Sea level pressure is approximately 1013 HPa.
Isobar - a line of constant pressure that connects points on a weather map that have the same pressure.
Low - A cyclonic storm that forms along a front.
Mesoscale - Scale of meteorological phenomena that range in size from a few km to about 100 km.
Millibar - A unit to measure atmospheric pressure. Normal sea level pressure is approximately 1013 mb.
Meteorology - The study of the atmosphere and its phenomena.
Parcel - An small imaginary volume of air a few meters wide to explain the behavior of air.
Paschal - A unit to measure atmospheric pressure. 100 Pa equals 1 mb. Normal sea level pressure is approximately 101300 Pa.
Precipitation - Water particles (liquid or frozen) that fall from the atmosphere and reach the ground.
Relative humidity - A measure of the moisture content of the air expressed in percent.
Ridge- Elongated area of high pressure.
Stationary Front - A front that moves very little with winds on each side of the front parallel and opposite in direction to each other.
Troposphere- the lowest layer (0 - 11 km) of the atmosphere. The top is called the tropopause.
Trough - An elongated area of low pressure.
Warm front - A front that moves in such a way that warm air replaces receding cold air.
Weather -The condition of the atmosphere at any particular time or place.
Wind - The motion of the air.
Wind direction - The direction from which the wind is blowing
Definitions are from Meteorology Today: An introduction to weather, climate, and the environment. 4th ed. By C. Donald Ahrens, 1991. West Publishing Company.
* Introduction to Boundary Layer Meteorology by Roland Stull.