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Comparison between the Boundary Layer and the Free Atmosphere
| Property | Boundary Layer | Free Atmosphere |
| Turbulence | Almost continuously turbulent over its whole depth | Turbulence in convective clouds, and sporadic clear-air turbulence in thin layers of large horizontal extent |
| Friction | Strong drag against earths surface. Large energy dissipation | Small viscous dissipation |
| Dispersion | Rapid turbulent mixing in the vertical and horizontal | Small molecular diffusion. Often rapid horizontal transport by mean wind. |
| Winds | Near logarithmic wind speed profile in the surface layer. Subgeostrophic, cross-isobaric flow common | Winds nearly geostrophic |
| Vertical Transport | Turbulence dominates | Mean wind and cumulus-scale dominate |
| Thickness | Varies between 100 m to 3 km in time and space. Diurnal oscillations over land | Less variable. 8-18 km. Slow time variations. |
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