Simulation of Air Pollution by Carbon Monoxide in Kislovodsk: Effects of Orography and Vehicle Emission Correction

Simulation of air pollution in mountainous regions is difficult due to the complex interaction of orography with atmospheric dynamics and uncertainty in anthropogenic emission. This paper discusses simulation of atmospheric pollution by carbon monoxide (CO) in complex mountainous terrain for the case of Kislovodsk region with the use of the mesoscale meteorological model WRF and the chemical transport model CHIMERE. The results are validated against instrumental measurements at the High-Mountain Scientific Station of A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. It is shown that refining the EMEP emission database by incorporating local features of the road network (density and road types) and their daily/weekly dynamics enables the spatial distribution of pollution sources to more closely approximate the actual layout of the regional road network and improves the accuracy of reproducing the daily cycle of CO concentrations. The contribution of orographic factors to the total pollution has been assessed. It is ascertained that the complex terrain of the region accounts for 20–50% of the average CO concentration level and creates zones of pollutant accumulation and dispersion. The statistical analysis shows satisfactory agreement between the simulation results and observations. The study confirms the feasibility and efficiency of the WRF-CHIMERE system in monitoring and analyzing atmospheric air quality in resort regions with complex orography. The results can serve a foundation for fundamental and applied scientific research aimed at studying the causes of periods with adverse environmental conditions. The air quality simulation can be used by local government authorities for urban planning, road network optimizing, developing recreational areas with allowance for orography, and improving regional environmental monitoring systems.