On the Turbulent Diffusion in the Atmosphere (II)

[摘要] The author discusses on some atmospheric phenomena of turbulent diffusion utilizing the following formula for the Lagrangian correlation coefficient R(ξ)=1-(ξ/τ0), obtained by the same author in a preceding paper.For the horizontal diffusion, τ0 usually means the lifetime of the effective largest turbulon which is proportional to the time duration T of observation, and τ0 becomes larger the longer the phenomenon persists. Thus the horizontal diffusion usually belongs to the I-class diffusion. Accordingly, the diffusing angle increases in proportion to T1/2 and the linear zone of diffusion continues farther. In this case, we again get the four-thirds power law for the diffusion coefficient.For the vertical diffusion, since the life-time of the vertical largest turbulon is elated with the height itself and is comparatively short, the II-class zone of turbulent diffusion is attained after a comparatively short time interval. The separating point between the two zones of diffusion is related to the length of the largest turbulon, and measuring this point we can estimate the length of the vertical largest turbulon (the mixing length) directly

[学科分类] 大气科学