Atmospheric Boundary Layer


Also found in: Acronyms.

atmospheric boundary layer

[¦at·mə¦sfir·ik ′bau̇n·drē ‚lā·ər]
(meteorology)

Atmospheric Boundary Layer

 

(or friction layer, planetary boundary layer), the air layer adjacent to the earth’s surface. Because of the intense turbulent mixing that occurs in it, its properties are determined primarily by the thermal and dynamic influence of the underlying surface. The thickness of the layer ranges from 300—400 m to 1-2 km. The greater the roughness of the underlying surface and the more intense the turbulence, the greater the thickness. For this reason, the thickness increases with increasing wind speed and decreasing thermal stability of the atmosphere. Transfer of heat and moisture between the earth’s surface and the free atmosphere lying above the layer is accomplished through the layer. The layer is characterized by an especially high level of contamination by dust and condensation products. Up to an altitude of 100 m wind speed within the layer increases approximately in proportion to the logarithm of the altitude; above 100 m it increases more and more slowly.

REFERENCE

Laikhtman, D. L. Fizika pogranichnogo sloia atmosfery, 2nd ed. Leningrad, 1970.
References in periodicals archive ?
Consequently, sustained warm SSTs and enthalpy flux help support warm, moist atmospheric boundary layer conditions (via 0E), which have been shown in previous literature to aid in TC intensification.
Launder, "Ground effects on pressure fluctuations in the atmospheric boundary layer," Journal of Fluid Mechanics, vol.
On the floor of the domain, a slip wall boundary condition is defined which may appear counter-intuitive in the simulation of a realistic atmospheric boundary layer. For these simulations, the intention is to maintain the same sheared wind velocity profile that is defined at the inlets at the vehicle.
observed the meteorological elements of the atmospheric boundary layer such as temperature, humidity, and pressure by using SUMO, a small fixed-wing UAV, and achieved good results [11].
Nonaka et al., "Atmospheric sounding over the winter Kuroshio Extension: effect of surface stability on atmospheric boundary layer structure," Geophysical Research Letters, vol.
In addition, a possible influence of the height of the atmospheric boundary layer was detected, suggesting that further studies are needed.
The aim of the investigation is to evaluate the effect of meteorological conditions and product loading indicator on the change of VOCs concentration in lower atmospheric boundary layer during different seasons in the territories adjacent to the oil terminals.
CFD simulations of atmospheric boundary layer flow over a numerical roughness fetch (e.g.
a) The exponent a is constant all over the thickness of the atmospheric boundary layer, up to [z.sub.g = [delta]], where the velocity is equal to the geostrophic wind velocity G.
He added that thermal inversions and the high incidence of cloud fog commonly at or above this regional atmospheric boundary layer may explain the summit's resistance to climate warming, "but this does not imply that there is an infinite capacity to resist future climate warming."
The ground-based nature of potential Army HEL engagements will be strongly affected by the required long, oblique slant paths through the dense atmospheric boundary layer. Additionally, the most stressing effects of aerosols and optical turbulence, which create distortions within the atmosphere, will often occur near the aperture of the HEL, where any induced bending or spreading of the energy is more likely to reduce the weapon's effectiveness.

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