On the nature of long-period variations in mass concentration of near-ground aerosol

Resumo

Variations in the aerosol concentration with periods more than one month are analyzed using measurements of mass concentration of the near-ground aerosol at Zvenigorod Scientific Station of the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. It is shown that the variations can be associated with the periodic recurrences of atmospheric transport trajectories from certain directions. We considered the cases when long-period variations in aerosol concentration were due to episodes of increased or decreased concentrations caused by aerosol advection from the corresponding directions. In particular, the 1.5-month variations in the aerosol mass concentration in 1995 were found to be due to the 1.5-month recurrences of the concentration maxima caused by southeasterly transport. The three-month periodicity of the transport episodes from directions of Baltic and North Atlantic in 2004 manifested themselves in 3-month recurrence of the aerosol concentration minima. A statistical relation is revealed between the near-ground aerosol concentration and the Arctic upper troposphere dynamics.