Transactions American Geophysical Union · 1958 · 379 citations · 1 references
Natural SciencesEarth SciencesMeteorologyAtmospheric ScienceAtmospheric ThermodynamicsBoundary Layer MeteorologyAtmospheric Boundary LayerAtmospheric Surface LayerBoundary-layer DynamicsBoundary-layer StructurePlanetary Boundary LayerBoundary Layer Wind ProfilesBoundary-layer DepthLapse ProcessesLogarithmic Wind LawRoughnessSurface LayersThermal StabilityWind
When air in equilibrium with one surface passes to another with different roughness, a layer forms where the air adjusts to the new surface, and this layer generally grows in depth downwind. Using a logarithmic wind‑speed distribution and Karman's integral equation, the authors compute the layer height theoretically as a function of distance, and a dimensional argument confirms that the boundary layer grows as the 4/5 power of downwind distance, independent of wind speed. Thermal stability slightly affects the layer height, raising it in lapse conditions and lowering it in inversions, and some data qualitatively support these results but are not conclusive.
When air, whose wind profile is in equilibrium with an underlying surface, passes to another surface with different roughness, a layer is formed in which the air has adjusted to the new surface. Generally this layer will grow in depth downwind. Assuming the logarithmic wind‐speed distribution and Karman's integral equation the height of this layer is computed theoretically as a function of distance. A dimensional argument is also presented which qualitatively confirms the result that the boundary layer grows as the ⅘ power of the distance downwind and is independent of wind speed. The effect of thermal stability is estimated and found to be relatively small, raising the height of the layer in lapse conditions and lowering it in inversions. Some data are discussed which qualitatively confirm those results but which cannot be considered to be conclusive.
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