Wind gradient

Not to be confused with gradient wind.
This article is about the interaction of horizontal wind with the earth's surface. For a more general treatment of related phenomena, see wind shear.

In common usage, wind gradient, more specifically wind speed gradient[1] or wind velocity gradient,[2] or alternatively shear wind,[3] is the vertical component of the gradient of the mean horizontal wind speed in the lower atmosphere.[4] It is the rate of increase of wind strength with unit increase in height above ground level.[5][6] In metric units, it is often measured in units of meters per second of speed, per kilometer of height (m/s/km), which reduces inverse milliseconds (ms−1), a unit also used for shear rate.

  1. ^ Hadlock, Charles (1998). Mathematical Modeling in the Environment. Washington: Mathematical Association of America. ISBN 978-0-88385-709-0. Thus we have a "wind-speed gradient" as we move vertically, and this has a tendency to encourage mixing between the air at one level and the air at those levels immediately above and below it.
  2. ^ Gorder, P.J.; Kaufman, K.; Greif, R. (1996). "Effect of wind gradient on the trajectory synthesis algorithms of the Center-TRACON Automation System (CTAS)". AIAA, Guidance, Navigation and Control Conference, San Diego, CA. American Institute of Aeronautics and Astronautics. ...the effect of a change in mean wind velocity with altitude, the wind velocity gradient... [permanent dead link‍]
  3. ^ Sachs, Gottfried (2005-01-10). "Minimum shear wind strength required for dynamic soaring of albatrosses". Ibis. 147 (1): 1–10. doi:10.1111/j.1474-919x.2004.00295.x. ...the shear wind gradient is rather weak....the energy gain...is due to a mechanism other than the wind gradient effect.
  4. ^ Oke, T. (1987). Boundary Layer Climates. London: Methuen. p. 54. ISBN 978-0-415-04319-9. Therefore the vertical gradient of mean wind speed (dū/dz) is greatest over smooth terrain, and least over rough surfaces.
  5. ^ Crocker, David (2000). Dictionary of Aeronautical English. New York: Routledge. pp. 104. ISBN 978-1-57958-201-2. wind gradient = rate of increase of wind strength with unit increase in height above ground level;
  6. ^ Cite error: The named reference Wizelius was invoked but never defined (see the help page).