gradient wind

[′grād·ē·ənt ‚wind]

(meteorology)

A wind for which Coriolis acceleration and the centripetal acceleration exactly balance the horizontal pressure force.

gradient wind

Gradient wind and balance of forces in a depression in the Northern Hemisphere.

Any horizontal wind velocity tangent to the contour line of a constant pressure surface or an isobar. This movement of air is to the result of a combination of three forces: pressure gradient force, geostrophic force, and cyclostrophic force. In the Northern Hemisphere, the difference between the pressure gradient directed inward toward low pressure and the Coriolis force directed outward results in the centripetal force in a low-pressure area. Similarly, in anticyclonic motion, the difference between the Coriolis force and the pressure gradient results in the centripetal force.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Gradient Wind

a horizontal, uniform motion of air in the absence of frictional force in a linear (geostrophic wind) or circular path that coincides with the isobars. The gradient wind blows when there is a balance between the active force of pressure gradient and inertial forces: centrifugal force and deflective force owing to the earth’s rotation—the Coriolis force. The gradient wind is the best approximation of the actual state of wind in a free atmosphere above the layer of friction (approximately 1,000 m above the earth’s surface).

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References in periodicals archive

The pressure gradient from the edge of the eye to the center was more than 8 mb (in a distance of 20 miles).This is sufficient to sustain a 45-mph gradient wind, at a radius of 10 miles from center (and 10 miles from the edge of the eye).

Exploring Eye of Typhoon "Marge," 1951

Finally, simulation experiments under gradient wind and random wind verify that the proposed control strategy can achieve optimal torque tracking and reactive power regulation and is robust to parameter uncertainties such as network voltage, network frequency, rotor resistance, and mutual inductance.

Maximum Wind Power Tracking of Doubly Fed Wind Turbine System Based on Adaptive Gain Second-Order Sliding Mode

The initial axisymmetric vortex is in hydrostatic and gradient wind balance.

Finally, the tangential velocity [v.sub.T] (r, z) is derived by the gradient wind balance, which is given by

A New Vortex Initialization Scheme Coupled with WRF-ARW

Gradient wind describes a wind field's steady energy that is changing slowly over time; it can be expressed as a superposition of a gradient component and the basic wind speed

In the above expression, [A.sub.[omega]r] is the maximum of gradient wind; [T.sub.sr] and [T.sub.er] are the starting time and ending time of the gradient wind respectively.

Harmonic analysis by modeling and simulation of the wind farm based on DFIG

Notice that in fine vortical structures, where the centrifugal force becomes important, the gradient wind balance (between pressure gradient, Coriolis and centrifugal forces) could advantageously replace the geostrophic balance for constraining slow modes.

Asimilacion de datos oceanicos en el norte de Chile: uso de un metodo 3DVAR

One of the tough things to work out at this part is the transition between the sea breezes and the gradient wind. You can have people on the inside of you powering down the coast in the sea breeze and people passing by in the gradient wind, and you're sitting in this meteorological transition zone.

Points of interest: Wild Oats XI navigator Adrienne Cahalan highlights the most challenging parts of the 628 nautical mile Rolex Sydney Hobart racecourse

Examples of specific topics covered include aircraft electrification, airmass, anabatic wind, boundary layer, convection, Dansgaard-Oeschger event, Dobson spectrophotometer, gradient wind, katabatic wind, meteorology, noble gases, pollution control, temperature scales, waterspout, and Venturi effect.

Encyclopedia of weather and climate, rev.ed.; 2v

Then gradient wind data classified as arising from neutral conditions were adopted to calculate the ground truth aerodynamic roughness length at different orientations using fitting iteration method [17].

Urban Aerodynamic Roughness Length Mapping Using Multitemporal SAR Data

As long as the gradient wind does not exceed 23 knots, we would normally expect the morning NW wind to decrease and a SE sea breeze to develop over the Derwent around noon, local summer time.

Winds of change the final run up the River Derwent to the finish line is a notoriously difficult stretch of the Rolex Sydney Hobart Race, so understanding the wind patterns in the southeast Tasmania is a huge advantage

(ii) Under any kind of offshore gradient wind flow, Storm Bay is affected by the significant topographic features of southern Tasmania and can be most frustrating.

Tricky Tassie coast. (Special Feature - Weather)