In this paper we describe a sampling and analysis technique that uses the binomial distribution to characterize stratospheric aerosol populations at the 95% level of confidence. Particle samples obtained over Alaska during July 15‐19, 1979, are used; the results show the presence of more small particles at lower altitude than at high altitudes. We also give calculations of the surface area and volume distributions for all aerosol samples collected. Evidence from these data suggests either that Aitken nuclei are injected or diffused across the tropopause and rise into the stratosphere, where they mature into larger particles, or nuclei form in the lower stratosphere and become mature aerosols at high altitude. Samples obtained at another site give the same results, supporting the view that the process of injection or nucleation and maturing of aerosols with altitude may be global and need not occur only in locations exhibiting unique meteorologic feature