Abstract
The effect of turbulent concentration fluctuations in the near-source region on fast, second-order atmospheric reactions of the type A + B → C is investigated. The correlation term C′ AC′ B is related to the concentration variance of emitted species A, C′ A 2 . The specific reactions studied are those pertaining to NO-O 3-NO 2 chemistry. A locally one-dimensional finite element method (LOD-FEM) is used to solve the three-dimensional transport/chemistry equations. By evaluating the differences in the photostationary-stale parameter (λ = k 3 C NOC O 3 k 1C NO 2 ) , the effect of the fluctuation term, C NO′C′ O 3 , is shown to be substantial in the near-source region. The effect initially increases with downwind distance, and then decreases as diffusion and dissipation become dominant. Within the plume itself, the effects are smallest at the core of the plume and are most pronounced at the plume edges. The important dynamical parameters are the eddy diffusivity used for closure of the turbulent species transport equation and the dissipation of turbulent energy that controls the small-scale fluctuations. From a diurnal standpoint, the maximum effect is observed at around noontime, with minimal effects being observed in the early morning and late evening.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.