Evolution of perturbations in 3D photochemical models
Kioutsioukis I., D. Melas, C. Zerefos and I. Ziomas
[abstract] This study utilises a general approach, based on perturbation theory, to facilitate the sensitivity analysis of a Photochemical Air Quality Model (PAQM). Specifically, we apply an automatic differentiation tool in the three-dimensional (3D) PAQM CAMx in order to calculate the gradient of the solution vector with respect to input parameters. To demonstrate the utility of the methodology, we address the sensitivity of the modelled concentrations to perturbations at the boundary conditions. The selected domains for the validation of the method had fundamental differences in topography, meteorology and emissions (Athens and Milan). Our results demonstrate that the maximum change in O3 arises from perturbations at the boundary conditions of O3 while the effect, in O3, of the boundary perturbations in NOX and VOC was an order of magnitude less.