AEROSOL-SIZE DISTRIBUTIONS IN ARCTIC HAZE DURING THE POLAR SUNRISE EXPERIMENT 1992

Measurements of particle number and mass size distributions of the atm ospheric aerosol in the lower troposphere were made during the Polar S unrise Experiment from January 20 to April 20, 1992, at Alert, Canada (82.5 degrees N, 62.3 degrees W). Particle number concentrations were determined by means of laser scattering particle counters and ranged f rom 50 to 600 cm(-3) in the accumulation mode. Particle mass size dist ributions were measured using a Berner low-pressure impactor; the tota l suspended particle mass ranged from 2.4 to 8.6 mu g m(-3). Average d ensities of (1.52 +/- 0.07) and (2.58 +/- 0.48) g cm(-3) were calculat ed for accumulation and coarse mode particles, respectively, by combin ing impactor and optical size distributions. Boundary layer ozone conc entrations were positively correlated with particles of diameters less than 0.35 mu m and negatively with particles larger than 0.35 mu m. P articles in the size range 6-12 mu m were detected exclusively during low ozone episodes.