WIT Press


A New Eddy Diffusivity Parameterisation For Dispersion Models: Evaluation In Different Atmospheric Conditions

Price

Free (open access)

Paper DOI

10.2495/AIR010101

Volume

47

Pages

8

Published

2001

Size

603 kb

Author(s)

C. Mangia, I. Schipa, D.M. Moreira, T. Tirabassi, G.A. Degrazia & U. Rizzam

Abstract

A new eddy diffusivity parameterisation for dispersion models: evaluation in different atmospheric conditions C. Mangia*, I. Schipa*, D.M. Moreira^, T. Tirabassi^, G.A. Degrazia* & U. Rizza* * ISlAtA/CNR, Lecce, Italy * Universidade Luterana do Brasil, Canoas (RS), Brazil ^ /^AO/CAW, go/ogna, /Wy Universidade Federal de Santa Maria, Santa Maria, Brazil Abstract Accounting for the current knowledge of the atmospheric boundary layer a parameterisation for eddy diffusivity has been derived by using a model for the frequency spectrum of eddy energy. The new formulation, based on Taylor classical diffusion theory and further developments by Pasquill, adequately represents the turbulent mechanisms in the various regimes of the Planetary Boundary Layer (PEL) giving continuous values at all elevations and all stability conditions from unstable to stable. The formulations, included in an advanced analytical model, has been evaluated using data from field experiments in different

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