Quantifying NO<sub>x</sub> point sources with Landsat and Sentinel-2 satellite observations of NO<sub>2</sub> plumes.
Where this comes from
- Record sourced from PubMed, PMID 38913899.
- Also identified by DOI 10.1073/pnas.2317077121 and PMC identifier 11228473.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We show that the Landsat and Sentinel-2 satellites can detect NO<sub>2</sub> plumes from large point sources at 10 to 60 m pixel resolution in their blue and ultrablue bands. We use the resulting NO<sub>2</sub> plume imagery to quantify nitrogen oxides (NO<sub>x</sub>) emission rates for several power plants in Saudi Arabia and the United States, including a 13-y analysis of 132 Landsat plumes from Riyadh power plant 9 from 2009 through 2021. NO<sub>2</sub> in the plumes initially increases with distance from the source, likely reflecting recovery from ozone titration. The fine pixel resolutions of Landsat and Sentinel-2 enable separation of individual point sources and stacks, including in urban background, and the long records enable examination of multidecadal emission trends. Our inferred NO<sub>x</sub> emission rates are consistent with previous estimates to within a precision of about 30%. Sources down to ~500 kg h<sup>-1</sup> can be detected over bright, quasi-homogeneous surfaces. The 2009 to 2021 data for Riyadh power plant 9 show a strong summer peak in emissions, consistent with increased power demand for air conditioning, and a marginal slow decrease following the introduction of Saudi Arabia's Ambient Air Standard 2012.