Feasibility Study of On-line Detection of Sulphuric Acid Aerosols in the Atmosphere by Laser Photofragmentation and Plasma Spectroscopy

Abstract

A major interest of our Institute lies in the study of the atmospheric sulphur cycle and in the oxidation mechanism(s) of Dimethylsulfide (DMS) in air. DMS originates from the ocean biota and its crucial role in the formation of atmospheric aerosols is well-documented (1,2). When DMS is oxidized, it generates SO2 that can be further oxidized to H2SO4, inducing the production and growth of new aerosol particles that can act as cloud condensation nuclei and affect the Earth’s albedo (2). The possibility of detecting sulphuric acid aerosols with laser excitation has been discussed, to the best of our knowledge, only in one paper (3), where the aerosols generated by mixing SO3 and H2O were addressed with laser photons at 193 nm. The resulting broadband emission was attributed to sulphuric acid and was similar to the emission spectrum of gaseous SO2.