Winds and Atmospheric Circulation

Gale

A very strong wind, typically between 34 and 40 knots (39–46 mph). Gales can cause hazardous conditions, especially at sea.

Jet Stream

A narrow band of strong wind in the upper atmosphere that influences weather systems. These winds can steer storms and affect temperature patterns.

Jet Streak

A localized region of stronger winds within a jet stream, which can influence weather systems and storm development.

Katabatic Wind

A cold, dense wind that flows downhill under the force of gravity. These winds can cause rapid temperature drops and are common in polar and mountainous regions.

Chinook Wind

A warm, dry wind that descends the leeward side of mountains, causing rapid temperature increases. It’s common in the Rocky Mountains region.

Foehn Wind

A warm, dry wind on the leeward side of mountains, similar to Chinook winds, known in Europe and other regions.

Zonda Wind

A hot, dry wind descending the eastern slopes of the Andes in Argentina, similar to a Foehn wind.

Sea Breeze

A local wind blowing from the sea toward the land, caused by temperature differences between the two.

Trade Winds

Persistent easterly winds found in the tropics, important for global circulation and weather patterns.

Zonal Wind

Winds that flow predominantly along lines of latitude, usually from west to east.

Zonal Flow

Atmospheric flow pattern that moves west to east along latitude lines. Zonal flow often brings stable weather conditions.

Anabatic Wind

A wind that blows upslope during the day as the sun heats mountain slopes causing air to rise. It often contributes to local convection and cloud development.

Ekman Spiral

The theoretical model describing how wind-driven surface ocean currents rotate with depth due to the Coriolis effect, important in ocean-atmosphere interactions.

Froude Number

A dimensionless number used to describe flow regimes in fluids, particularly important in studying airflow over mountains and the formation of waves.

Geostrophic Wind

Wind that results from the balance between the Coriolis force and the pressure gradient force, flowing parallel to isobars in the upper atmosphere.

Intertropical Convergence Zone (ITCZ)

A region near the equator where trade winds converge, causing frequent thunderstorms and heavy rainfall. It migrates seasonally and influences tropical weather.

Kelvin-Helmholtz Instability

A fluid instability that occurs when there is velocity shear in a continuous fluid or between two fluids, sometimes producing distinctive wave clouds.

Kelvin-Helmholtz Wave

Atmospheric waves formed due to shear between two layers of air moving at different velocities, sometimes visible as wave clouds.

Marine Layer

A cool, moist air mass that forms over the ocean and can move inland, often causing fog and low clouds.

Madden-Julian Oscillation (MJO)

An eastward-moving disturbance of clouds, rainfall, and winds near the equator with a cycle of 30-60 days influencing tropical weather.

Monsoon

A seasonal wind pattern that causes wet and dry seasons, typically involving a reversal in wind direction and associated with heavy rainfall.

Nocturnal Jet

A low-level jet stream that forms at night due to temperature differences between land and air, affecting nighttime weather.

Thermal Wind

The change in wind speed or direction with height due to horizontal temperature gradients.

Vertical Wind Shear

The change in wind speed or direction with altitude, important in storm development and aviation safety.

Wind Shear

A change in wind speed or direction over a short distance. Wind shear can influence storm intensity and aviation safety.