Long-Term Global SO2 Data Record from Aura/OMI: Latest Updates, Recent Applications, and Comparisons with TROPOMI

Since launched aboard NASA’s Aura spacecraft in 2004, the Dutch/Finnish Ozone Monitoring Instrument (OMI) has been providing global observations of anthropogenic and volcanic SO₂. The standard OMI SO₂ data, produced at NASA Goddard Space Flight Center, have been used in a number of studies on SO₂ emissions and transport, as well as in everyday applications such as aviation disaster avoidance. The current OMI SO₂ data are based on a principal component analysis (PCA) retrieval technique that significantly reduces the noise and artifacts in retrievals, leading to improved sensitivity to SO₂ emission sources. In this presentation, we offer an overview of the latest updates that are being made to further improve the OMI SO₂ product. In particular, we will discuss the implementation of a new SO₂ Jacobians lookup table that allows us to more accurately estimate the instrument sensitivity to SO₂ for each individual pixel. We show that, the new lookup table, along with more realistic a priori SO₂ profiles, help to further improve the accuracy of SO₂ retrievals. We also highlight a few recent examples using OMI SO₂ data in research and applications. One such example is the use of OMI SO₂ data to study long-range transport of pollution out of East Asia. Another example is the use of OMI and other satellite data to monitor the air quality impact of the 2018 Kilauea eruption in Hawaii. Finally, we also make comparisons between the OMI SO₂ data and the first results from TROPOMI. We show that the two data products are largely consistent despite differences in both algorithms and instrument characteristics. This demonstrates the potential to extend and enhance the OMI SO₂ data record using TROPOMI.