Geostrophic wind level: Difference between revisions

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<div class="definition"><div class="short_definition">(''Also called'' gradient wind level.) The lowest level at which the [[wind]]  becomes [[geostrophic]] in the theory of the [[Ekman spiral]], proportional to (&#x003bd;/sin&#x003c6;)<sup>&frac12;</sup>, where &#x003bd; is  the kinetic [[eddy viscosity]] and &#x003c6; the latitude.</div><br/> <div class="paragraph">In practice it is observed that the geostrophic wind level is often between 1 and 2 km, and it  is assumed that this marks the upper limit of frictional influence of the earth's surface. The  geostrophic wind level may be considered to be the top of the [[Ekman layer]] and [[planetary  boundary layer]], that is, the base of the [[free atmosphere]].</div><br/> </div>
<div class="definition"><div class="short_definition">(''Also called'' gradient wind level.) The lowest level at which the [[wind]]  becomes [[geostrophic]] in the theory of the [[Ekman spiral]], proportional to (&#x003bd;/sin&#x003c6;)<sup>&frac12;</sup>, where &#x003bd; is  the kinetic [[eddy viscosity]] and &#x003c6; the latitude.</div><br/> <div class="paragraph">In practice it is observed that the geostrophic wind level is often between 1 and 2 km, and it  is assumed that this marks the upper limit of frictional influence of the earth's surface. The  geostrophic wind level may be considered to be the top of the [[Ekman layer]] and [[planetary boundary layer|planetary  boundary layer]], that is, the base of the [[free atmosphere]].</div><br/> </div>
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Latest revision as of 16:04, 25 April 2012



geostrophic wind level

(Also called gradient wind level.) The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral, proportional to (ν/sinφ)½, where ν is the kinetic eddy viscosity and φ the latitude.

In practice it is observed that the geostrophic wind level is often between 1 and 2 km, and it is assumed that this marks the upper limit of frictional influence of the earth's surface. The geostrophic wind level may be considered to be the top of the Ekman layer and planetary boundary layer, that is, the base of the free atmosphere.


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