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- Author or Editor: J. A. Businger x
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Abstract
By reviewing the physics of the processes leading to dry deposition in the atmospheric surface layer, a number of corrections and possible errors in the determination of the dry deposition fluxes are identified. The concept of deposition velocity is examined, its usefulness discussed, and some pitfalls are pointed out. An overview is given of the various micrometeorological methods with which dry deposition can be determined and some of their limitations are indicated. With this background a number of recent publications on dry deposition have been analyzed. It is apparent that in most cases a more complete documentation is needed of the structure of the surface layer and the adjacent planetary boundary layer. Errors related to advection and entrainment are especially difficult or impossible to assess because of inadequate information about the surroundings and the height of the boundary layer.
Abstract
By reviewing the physics of the processes leading to dry deposition in the atmospheric surface layer, a number of corrections and possible errors in the determination of the dry deposition fluxes are identified. The concept of deposition velocity is examined, its usefulness discussed, and some pitfalls are pointed out. An overview is given of the various micrometeorological methods with which dry deposition can be determined and some of their limitations are indicated. With this background a number of recent publications on dry deposition have been analyzed. It is apparent that in most cases a more complete documentation is needed of the structure of the surface layer and the adjacent planetary boundary layer. Errors related to advection and entrainment are especially difficult or impossible to assess because of inadequate information about the surroundings and the height of the boundary layer.
Abstract
Corrections to the sensible heat flux due to fluctuations in the specific humidity recently proposed by Brook (1978) have been shown to be incorrect by Frank and Emmitt (1981). However, it is easy to misinterpret Frank and Emmitt’s paper. Here an effort is made to clarify the issue and to sketch what its importance is to the energy balance of the hydrological cycle. By expanding the specific enthalpy flux into the fluxes of sensible heat and latent heat, it is found that a good first-order approximation shows that no corrections are necessary, which is in agreement with Frank and Emmitt's result.
Abstract
Corrections to the sensible heat flux due to fluctuations in the specific humidity recently proposed by Brook (1978) have been shown to be incorrect by Frank and Emmitt (1981). However, it is easy to misinterpret Frank and Emmitt’s paper. Here an effort is made to clarify the issue and to sketch what its importance is to the energy balance of the hydrological cycle. By expanding the specific enthalpy flux into the fluxes of sensible heat and latent heat, it is found that a good first-order approximation shows that no corrections are necessary, which is in agreement with Frank and Emmitt's result.
Abstract
A concept for the mixing length in diabatic conditions is introduced and elaborated. The basic idea is that convective energy has effect on the mixing length but not on the size of the largest eddies. The theory developed on this concept of the mixing length for the diabatic wind profile gives satisfactory agreement with observations over a wide stability range.
Abstract
A concept for the mixing length in diabatic conditions is introduced and elaborated. The basic idea is that convective energy has effect on the mixing length but not on the size of the largest eddies. The theory developed on this concept of the mixing length for the diabatic wind profile gives satisfactory agreement with observations over a wide stability range.
Abstract
No abstract available.
Abstract
No abstract available.
Abstract
With Prandtl's theory of the mixing length as the point of beginning, a theory concerning the structure of the atmospheric surface layer is proposed on similar assumptions as were put forward by Lettau. The novel feature in the present treatment lies in the fact that the acceleration due to the frictional part of the turbulence is considered to be dependent on stability, whereas Lettau assumed a constant value for this acceleration. Although this theory is not exact, it may promote a better understanding of atmospheric turbulence.
A dimensionless stability number is introduced; it enables one to obtain a simple survey of all states of the atmospheric surface layer. The theory is tested with observations of Rider (1954). The requirements for a further experimental program are established.
Abstract
With Prandtl's theory of the mixing length as the point of beginning, a theory concerning the structure of the atmospheric surface layer is proposed on similar assumptions as were put forward by Lettau. The novel feature in the present treatment lies in the fact that the acceleration due to the frictional part of the turbulence is considered to be dependent on stability, whereas Lettau assumed a constant value for this acceleration. Although this theory is not exact, it may promote a better understanding of atmospheric turbulence.
A dimensionless stability number is introduced; it enables one to obtain a simple survey of all states of the atmospheric surface layer. The theory is tested with observations of Rider (1954). The requirements for a further experimental program are established.
Abstract
A sonic anemometer-thermometer, based on transmission of continuous sound waves and determination of phase angle variations, has been developed. The instrument is designed to measure the fluctuations in the vertical wind component and temperature simultaneously. Measurement of these two quantities enables one to determine the eddy heat flux in the turbulent boundary layer. Field tests indicate that the instrument performs satisfactorily.
Abstract
A sonic anemometer-thermometer, based on transmission of continuous sound waves and determination of phase angle variations, has been developed. The instrument is designed to measure the fluctuations in the vertical wind component and temperature simultaneously. Measurement of these two quantities enables one to determine the eddy heat flux in the turbulent boundary layer. Field tests indicate that the instrument performs satisfactorily.
