Gas diffusion in a convection layer near a coastal region

Thermal internal boundary layer (TIBL) in onshore wind has a significant in fluence on dispersion of air pollutants and causes fumigation which brings high ground level concentration (GLC) of pollutants. A wind tunnel experime nt was conducted in the thermally stratified wind tunnel of Nagasaki Resear ch & Development Center, MHI, Japan, for the purpose of investigating the e ffect of TIBL on GLC and turbulent statistical properties. Numerical simula tions using a Lagrangian stochastic dispersion model were also conducted an d its results were compared with wind tunnel results and filed observation. Concerning GLC, they showed good agreement and this confirms the usefulnes s of a Lagrangian stochastic model in practical application to predict GLC in coastal areas. (C) 1999 Elsevier Science Ltd. All rights reserved.