An intercomparison of aircraft sulfur dioxide measurements in clean and polluted marine environments
Year: 2026
Type: article
Abstract: . The University of York’s laser-induced fluorescence (LIF) instrument for measuring sulfur dioxide (SO2) was compared to a commercial pulsed fluorescence (PF) and iodide chemical ionisation mass spectrometer (I-CIMS) aboard the UK FAAM research aircraft in both remote and ship-polluted marine environments. In high SO2 concentration plumes LIF and PF compared well, but LIF was the only instrument capable of SO2 measurements in the remote marine boundary layer due to its campaign limit of detection (LoD, 3 σ) of 0.07 ppb at 10 seconds compared with 0.4 ppb for the PF. Quantification of SO2 using I-CIMS was challenging due to a significant interference, but good signal correlation with the other instruments was observed in polluted air mases. A comparison of response time was also made, for which the I-CIMS and LIF proved much faster than the PF with 3-efolding times of 0.6, 2 and 17 seconds respectively. This work demonstrates the importance of sensitive instrumentation like the LIF for quantifying low concentrations of SO2, such as over remote marine environments, at the time resolutions required for a fast moving platform. This is particularly relevant now as a result of more stringent sulfur emission regulations for shipping, and likely more so in the future as anthropogenic SO2 concentrations continue to decline.
Institutions: Plymouth Marine Laboratory, University of York, University of Manchester, Royal Holloway University of London, Facility for Airborne Atmospheric Measurements, National Centre for Atmospheric Science, Cranfield University, Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), National Oceanic and Atmospheric Administration, NOAA Chemical Sciences Laboratory
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,585
OpenAlex ID: W7129434143