Field Use of Intensity of Turbulence, Richardson'S Number and Eddy Diffusivity to Make Diffusion Calculations

摘要

The report consists of five sections. Section I is an introduction. Sections II through V treat related subjects. Section II demonstrates the accuracy to be expected from diffusion dosage calculations which make use of direct measurements of intensity of turbulence and wind speed. Section III uses a derived expression for the relationship of Richardson's number to intensity of turbulence, and the resulting dosage calculations are discussed. Section IV tests the universality of the derived relationship of Richardson's number to intensity of turbulence. Section V relates the variance of vertical wind speeds at different sites and altitudes to Richardson's number. Section V further treats some of the problems involved in calculating and using eddy diffusivity to make dosage calculations and suggests a way of calculating eddy diffusivity at heights between the top of the surface boundary layer and the gradient wind level. (Author)