VOLATILITY OF LABORATORY GENERATED AND NATURAL AEROSOL.

Studies of the volatility of aerosols have to date been relatively sparse although some major components of the atmospheric aerosol such as the ammonium salts, sulphuric acid droplets, terpenes and many hygroscopic particles are known to be volatile. Up to now most attention has been focused on measurements of the volatile properties of cloud condensation nuclei (CCN). In this work, the volatility of common aerosol constituents such as ammonium sulphate, ammonium chloride and sodium salts is measured in the laboratory with a light-scattering aerosol counter equipped with a temperature-controlled heated intake. Changes in the size distribution of the particles are measured as a function of aerosol temperature. The volatile properties of near-surface aerosols in remote regions of southern and central New Mexico, USA, are also measured over a one year period beginning September 1984.