Theoretical studies of diurnal wind-structure variations in the planetary boundary layer
β Scribed by K. Buajitti; A. K. Blackadar
- Publisher
- John Wiley and Sons
- Year
- 1957
- Tongue
- English
- Weight
- 958 KB
- Volume
- 83
- Category
- Article
- ISSN
- 0035-9009
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β¦ Synopsis
Abstract
Averages of the wind vector at four times of the day were evaluated for 29 suitable days during the summer of 1951 at Wichita, Kansas, and Oklahoma City. The periodic portion of the wind variation vector is an ellipse at all levels with the major axis approximately in the direction of the wind vector. The amplitude reaches a maximum at 2,500 ft above the ground.
The cause of the variation is sought by theoretical methods, first by finding what periodic variations would occur when the eddy viscosity is periodic in time and constant with height, and secondly by finding solutions with the aid of an electronic analogue computer for cases when the eddy viscosity is distributed arbitrarily with height. It is concluded that variations of the type which were observed can occur only when both the average value of the eddy viscosity and the amplitude of its variations decrease rapidly with height above the lowest third of the friction layer.
π SIMILAR VOLUMES
The equations of motions are solved for concentric circular flow in the planetary boundary layer (PBL) under the assumption of K = 1' I&/& and gradient wind independent of radius r. The theoretical distribution of wind is obtained for r 2 300 km. Other parameters of the PBL are also calculated. Fina
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Until recently, pollution dispersion models have made predictions on the basis that the pollutant concentration is Gaussian. Such is not the case for convective conditions where the observed vertical velocity distribution is skewed towards the updraught portion of the distribution. One recent disper
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