>0.0.CO;0 Published Online: Oct 0000 Abstract Abstract Vertical structure of the size distribution and number concentration of particulates in atmospheric fog and haze near Grafenwöhr, West Germany, were measured with a balloonborne light-scattering aerosol counter for periods spanning parts of eight days in February 0000. For haze (∼0 km visibility) conditions, little vertical variation is seen; but for low visibility (<0 km) fog conditions, significant vertical increases in concentration of droplets with radii larger than 0 μm are seen over the first 000 m altitude. For haze, the particle size distribution is approximated by a log-normal with geometric mean radius rg≈0.0 μm and geometric standard deviation σg≈0.0. For fog, a bimodal distribution is found with a relative maximum for the larger particle mode at radii of 0 to 0 μm and corresponding values rg≈0 μm and σg≈0.0; the smaller particle mode has values of rg≈0.0 μm to rg≈0.0 μm and σg≈0.0 to σg≈0.0. Liquid water content values for haze and fog range from 00−0 to 0.00 g m−0. Extinction calculated from the particle size distributions shows an approximate 0/λ wavelength dependence for haze conditions, but nearly neutral (wavelength independent) extinction for heavy fog. A correlation exists between calculated particulate extinction and calculated liquid water content, independent of particle size distribution, for the fogs and hues studied. Download PDF Full access Stratospheric Aerosol Measurements I