The Hurst coefficient and lacunarity applied to atmospheric sub-micron particle data

The study of air pollution is based on the characterization of sub-micrometric atmospheric particles, and the fractal analysis is a new tool for describing them. In order to obtain experimental data about the atmospheric particles emitted by vehicles, a Refinery and a Power Plant in the Tula region (Hidalgo State, Mexico), atmospheric particle concentrations were measured from March 24 to April 24 as part of the MILAGRO campaign (2006) at the Jasso Station by means of an SMPS. From the campaign days, 16 were selected to perform the fractal analysis of the experimental data through the Hurst coefficient (H) and lacunarity (L). In this work, the Hurst coefficient was associated with the variations (roughness) concerning both the particle concentrations and particle formation processes (nucleation, Aitken, accumulation), which are connected with the intensity of the emissions throughout time. As for lacunarity, it provided information about the distribution of the particle sizes (lagoons) and the type of particle formation processes occurring through the sampling days