<title>Temporal variability of microstructural parameters of near-ground aerosol: I. Annual and seasonal variability</title>

Abstract

Regular round-the-clock measurements of the total number density and disperse composition of aerosol particles of the radius range r=0.2-0.5 &mu;m were carried out at the aerosol monitoring station of LAO IAO SB RAS since 1999 till 2004 by means of the photoelectric counter of particles PKGTA. Temporal behavior of annual and monthly mean values of the measured parameters of particles of the noted size range is analyzed in the first part of the paper. Temporal variability of the total number density of aerosol particles N (r=0,2 &divide; 5 &mu;m) and the integral parameter K = Nsub(<b>r</b>=0,2 &divide;0,5 &mu;m)/ Ncoarse(<b>r</b> = 0,5 &divide; 1 &mu;m), which describes the general peculiarities of the behavior of the particle size distribution is analyzed. Annual and interannual behavior of the absolute values of the number density of submicron Nsub and coarse Ncoarse particles are studied, as well as the values normalized to the annual mean number density Nmean. Temporal behavior of the mean particle size distributions F = (4&pi;/3)r_i³&Delta;N_i/&Delta;r_i in different seasons is analyzed. Possible reasons affecting the peculiarities of the temporal behavior of the aforementioned parameters are discussed.