Plume dispersion, mixing and chemistry simulation using the Lagrangian Volumetric Particle Approach with realistic atmospheric chemical kinetics mechanisms

The Lagrangian Volumetric Particle Approach (VPA) of Cassiani (2013) has been implemented in an operational Lagrangian Stochastic particle dispersion model including a set of chemical kinetics equations for atmospheric chemistry. The Lagrangian particle model is coupled on-line with a grid based Eulerian Chemistry Transport Model (CTM) solving the same set of atmospheric chemical kinetics equations. By means of the Lagrangian VPA the high order covariances, resulting from the averaging operator applied to the non-linear chemical kinetics mechanism, appear in closed form. Therefore, the use of the VPA allows to model with a high level of accuracy both the near source turbulent dispersion and mixing, and the effects of atmospheric turbulence on the near source, highly non-linear, plume chemistry. The coupling with the Eulerian CTM allows for the separation of background and plume chemistry by using a plume-in grid scheme. This modelling system is developed in the Framework of the project FuNitr (Future Drinking Water Levels of Nitrosamines and Nitramines near a CO2 Capture Plant) investigating the potential chemical transformation in a plume emitted by a Carbon Capture and Storage (CCS) plant. Here we present the modelling system and some preliminary simulations of reactive plumes with a relatively reduced but realistic atmospheric chemical kinetic system. Reference: Cassiani M. (2013) The volumetric particle approach for concentration fluctuations and chemical reactions in Lagrangian particle and particle-grid models. Boundary-Layer Meteorology 146(2):207–233.