Top-down/bottom-up diffusion: Difference between revisions

From Glossary of Meteorology
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An [[atmospheric boundary layer]] theory that splits [[turbulent transport|turbulent  transport]] into two components, one that is entrained into the [[boundary layer]] top and then  diffused downward, and one that is injected from the earth's surface and brought upward into the  boundary layer.<br/> These two linearly decomposed components of a passive [[scalar]] assume that the top-down  component has zero [[flux]] at the surface while the bottom-up component has zero flux at the top.  This theory allows some aspects of vertical [[transport]] across a [[mixed layer]] to be modeled, even  though the actual vertical [[gradient]] of the passive scalar is zero, which is often the case for vigorous  [[buoyant convection]].
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== top-down/bottom-up diffusion ==
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<div class="definition"><div class="short_definition">An [[atmospheric boundary layer]] theory that splits [[turbulent  transport]] into two components, one that is entrained into the [[boundary layer]] top and then  diffused downward, and one that is injected from the earth's surface and brought upward into the  boundary layer.</div><br/> <div class="paragraph">These two linearly decomposed components of a passive [[scalar]] assume that the top-down  component has zero [[flux]] at the surface while the bottom-up component has zero flux at the top.  This theory allows some aspects of vertical [[transport]] across a [[mixed layer]] to be modeled, even  though the actual vertical [[gradient]] of the passive scalar is zero, which is often the case for vigorous  [[buoyant convection]].</div><br/> </div>
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Latest revision as of 23:45, 28 March 2024

An atmospheric boundary layer theory that splits turbulent transport into two components, one that is entrained into the boundary layer top and then diffused downward, and one that is injected from the earth's surface and brought upward into the boundary layer.
These two linearly decomposed components of a passive scalar assume that the top-down component has zero flux at the surface while the bottom-up component has zero flux at the top. This theory allows some aspects of vertical transport across a mixed layer to be modeled, even though the actual vertical gradient of the passive scalar is zero, which is often the case for vigorous buoyant convection.

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