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The wind gradient is said to be steep or pronounced when the change in wind speed with height is very rapid, and it is in these conditions that extra care must be used when taking off or landing in a glider. ^ Knauff, Thomas (1984). Glider Basics from First Flight to Solo. Thomas Knauff. ISBN 978-0-9605676-3-8.
Wind shear is a microscale meteorological phenomenon occurring over a very small distance, but it can be associated with mesoscale or synoptic scale weather features such as squall lines and cold fronts. It is commonly observed near microbursts and downbursts caused by thunderstorms, fronts, areas of locally higher low-level winds referred to ...
The wind profile power law relationship is. where is the wind speed (in metres per second) at height (in metres), and is the known wind speed at a reference height . The exponent ( ) is an empirically derived coefficient that varies dependent upon the stability of the atmosphere. For neutral stability conditions, is approximately 1/7, or 0.143.
The thermal wind is the change in the amplitude or sign of the geostrophic wind due to a horizontal temperature gradient. The geostrophic wind is an idealized wind that results from a balance of forces along a horizontal dimension. Whenever the Earth's rotation plays a dominant role in fluid dynamics, as in the mid-latitudes, a balance between ...
The quasi-geostrophic vorticity equation can be obtained from the and components of the quasi-geostrophic momentum equation which can then be derived from the horizontal momentum equation. (3) The material derivative in (3) is defined by. (4) where is the pressure change following the motion. The horizontal velocity can be separated into a ...
Betz's law. Schematic of fluid flow through a disk-shaped actuator. For a constant-density fluid, cross-sectional area varies inversely with speed. In aerodynamics, Betz's law indicates the maximum power that can be extracted from the wind, independent of the design of a wind turbine in open flow. It was published in 1919 by the German ...
The roughness length plays a part in determining the slope of the line. Roughness length ( ) is a parameter of some vertical wind profile equations that model the horizontal mean wind speed near the ground. In the log wind profile, it is equivalent to the height at which the wind speed theoretically becomes zero in the absence of wind-slowing ...
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed affects weather forecasting, aviation and maritime operations, construction projects, growth and ...