14. Frontal Depressions Flashcards
Term
Definition
Frontal Depression
A low-pressure system with associated fronts, typically leading to various weather phenomena like rain and winds.
Cold Front
The leading edge of a cooler mass of air, replacing (at ground level) a warmer mass of air.
Warm Front
A transition zone where a warm air mass is replacing a cold air mass.
Occluded Front
A composite front produced by occlusion, where a cold front overtakes a warm front and lifts the warm air above the earth’s surface.
Stationary Front
A pair of air masses, neither of which is strong enough to replace the other.
Air Mass
A volume of air defined by its temperature and water vapor content.
Barometric Pressure
The pressure exerted by the atmosphere at a given point, related to weather forecasting.
Isobar
A line on a map connecting points of equal atmospheric pressure.
Cyclonic Activity
Weather phenomena associated with large scales of air mass movement around a central region of low atmospheric pressure.
Anticyclone
A weather phenomenon characterized by large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere.
Jet Stream
A fast flowing, narrow air current found in the atmosphere around 10 kilometers above the surface of the Earth.
Weather Front
A boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena.
Tropopause
The boundary in the Earth’s atmosphere between the troposphere and the stratosphere.
Condensation
The process by which water vapor in the air is changed into liquid water.
Precipitation
Any form of water - liquid or solid - falling from the sky, such as rain, snow, sleet, or hail.
Dew Point
The atmospheric temperature (varying according to pressure and humidity) below which water droplets begin to condense and dew can form.
Vortex
A region within a fluid where the flow revolves around an axis line, which may be straight or curved.
Coriolis Effect
The effect whereby a mass moving in a rotating system experiences a force acting perpendicular to the direction of motion and to the axis of rotation.
Trough
An elongated region of relatively low atmospheric pressure, often associated with fronts.
Ridge
An elongated area of relatively high atmospheric pressure, usually associated with high-pressure systems.
Isotherm
A line on a map connecting points of equal temperature.
Advection
The transfer of heat or matter by the flow of a fluid, especially horizontally in the atmosphere.
Squall Line
A line of severe thunderstorms that can form along or ahead of a cold front.
