Central Campus Air Quality Model (CCAQM) Instructions
Horizontal and Vertical Dispersion Coefficients
Dispersion
varies from being fastest for very unstable conditions to being
slowest for very stable conditions.
Dispersion coefficients are the standard deviations of the
horizontal (σ_{y}) and vertical (σ_{z}) normal
distributions in units of meters. Empirical approximations have been developed to
calculate σ_{y}(x) and σ_{z}(x), where x is the
distance downwind from the source in units of kilometers. These
coefficients can be computed using the following information:
σ_{y}(x)
= ax^{0.894}
σ_{z}(x)
= cx^{d} + f
Parameters for calculating dispersion coefficients
