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A wind speed gradient of 4 (m/s)/km can produce refraction equal to a typical temperature lapse rate of 7.5 °C/km. [51] Higher values of wind gradient will refract sound downward toward the surface in the downwind direction, [52] eliminating the acoustic shadow on the downwind side. This will increase the audibility of sounds downwind.
The power law is often used in wind power assessments [4] [5] where wind speeds at the height of a turbine ( 50 metres) must be estimated from near surface wind observations (~10 metres), or where wind speed data at various heights must be adjusted to a standard height [6] prior to use.
If the wind is coming from the north, the closest it could sail would be ENE or WNW. In order to travel in that direction, it must "fall off," or move to an angle with the wind on one side or the other, a "tack." A ship tacks back and forth against the wind, or "beats," each tack earning it some "headway".
Thermal wind is a meteorological term not referring to an actual wind, but a difference in the geostrophic wind between two pressure levels p 1 and p 0, with p 1 < p 0; in essence, wind shear. It is only present in an atmosphere with horizontal changes in temperature (or in an ocean with horizontal gradients of density ), i.e., baroclinicity .
Proposition 17a in al-Tusi's medieval Arabic version of the book On Sizes states that the ratio of the distance of the vertex of the shadow cone from the center of the Moon (when the Moon is on the axis [that is, at the middle of an eclipse] of the cone containing the Earth and the Sun) to the distance of the center of the Moon from the center ...
A trough is an elongated area of lower air pressure. Since pressure is closely linked to wind, there are often changes in wind direction across a trough. If a trough forms in the mid-latitudes, a temperature difference at some distance between the two sides of the trough usually exists and the trough might become a weather front at some
Fir waves occur in forests on mountain slopes after wind disturbance, during regeneration. When trees fall, the trees that they had sheltered become exposed and are in turn more likely to be damaged, so gaps tend to expand downwind. Meanwhile, on the windward side, young trees grow, protected by the wind shadow of the remaining tall trees. [89]
They are oriented perpendicular to the wind in order to be most effective. [30] In regions with minimal vegetation, such as coastal and desert areas, transverse sand dunes orient themselves perpendicular to the prevailing wind direction, while longitudinal dunes orient themselves parallel to the prevailing winds.