High-sensitivity simultaneous SO2 using continuous wave quantum cascade laser IR absorption

Description

Aerosols play an important role in influencing the composition of the atmosphere, climate forcing, and human health. Secondary particles are formed and grow via gas to particle conversions in the atmosphere, including nucleation and condensation. We have developed a highly sensitive infrared absorption spectrometer using the latest developments in quantum cascade laser spectroscopy and an inlet system to enable quantitative and sensitive simultaneous measurements of sulfur dioxide. This species is the remote tropospheric source for production of sulfuric acid, a key aerosol precursor. Particulate sulfate is measured using the Aerodyne aerosol mass spectrometer, a chemically speciated mass-based aerosol instrument. Sensitive, direct measurements of sulfur dioxide will enable a better understanding of gas phase sulfuric acid measurements and secondary aerosol formation in the atmosphere. In this poster, the spectroscopy, instrument performance, and verification during various mobile field campaigns will be discussed.