Analysis and Numerical Modelling of Black Carbon and CO2 Concentration Peaks at a Remote Mountain Station

Peak values of CO2 and Black Carbon (BC) concentrations at the Plateau Rosa remote mountain site in the Italian Alps, representing a background monitoring station, are investigated. The study is conducted by analysing a long-term series of CO2 observations and a recent dataset of measured BC concentration. To determine the potential source areas of the pollutant masses reaching the site when peak concentration events occur, numerical simulations are performed with two Lagrangian particle dispersion models, MILORD, for the long-range, and FLEXPART, for the mesoscale and regional scale. It is found that the values of the concentration show a dependence on the season, with different behaviours for the CO2 and the BC. The analysis of some case studies using the Lagrangian atmospheric dispersion models enables to identify the main features of the synoptic and mesoscale transport.