Volatility of aerosols in the arid southwestern United States.

Volatile properties of aerosols at an isolated rural site in S-central New Mexico were measured with a light-scattering particle counter equipped with a temperature-controlled heated inlet. Intermittent measurements throughout a one-yr period show that submicro particles are highly volatile and display temperature-fractionation characteristics of ammonium sulfate or bisulfate. It is estimated that 60-98% of the submicron aerosol fraction (by mass) is composed of these sulfates. Larger supermicron particles which are composed mostly of quartz and clay minerals of soil origin, are relatively involatile.-from AuthorsUS Army Atmos Sci lab, White Sands Missile Range, NM 88002, USA.