OMI satellite observations of decadal changes in ground-level sulfur dioxide over North America

Abstract

Sulfur dioxide (SO2) has a significant impact on the environment and human health. We estimated ground-level sulfur dioxide (SO2) concentrations from the Ozone Monitoring Instrument (OMI) using SO2 profiles from the Global Environmental Multi-scale-Modelling Air quality and CHemistry (GEM-MACH) model over North America for the period of 2005-2015. OMI-derived ground-level SO2 concentrations (r=0. 61) and trends (r=0. 74) correlated well with coincident in situ measurements from air quality networks over North America. We found a strong decreasing trend in coincidently sampled ground-level SO2 from OMI (-81±19%) and in situ measurements (-86±13g%) over the eastern US for the period of 2005-2015, which reflects the implementation of stricter pollution control laws, including flue-gas desulfurization (FGD) devices in power plants. The spatially and temporally contiguous OMI-derived ground-level SO2 concentrations can be used to assess the impact of long-Term exposure to SO2 on the health of humans and the environment.