Top-Down NOx Emissions of European Cities Based on the Downwind Plume of Modelled and Space-Borne Tropospheric NO2 Columns

• Published in: Sensors (Basel, Switzerland) Vol. 18; no. 9; p. 2893
• Main Authors: Verstraeten, Willem W., Boersma, Klaas Folkert, Douros, John, Williams, Jason E., Eskes, Henk, Liu, Fei, Beirle, Steffen, Delcloo, Andy
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center MDPI 31.08.2018; MDPI AG
• Subjects: Chemistry; Computer simulation; Environment Pollution; Estimates; Industrial plant emissions; Lifetime; LOTOS-EUROS CTM; Nitrogen dioxide; OMI data; Organic chemistry; Ozone; Pollutants; Pollution; Simulation; Surface NO emissions; surface NOX emissions; Tropospheric NO column; tropospheric NO2 column; Urban areas; Belgium; United States > US; Netherlands; Nox Emissions
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s18092893

Top-down estimates of surface NOX emissions were derived for 23 European cities based on the downwind plume decay of tropospheric nitrogen dioxide (NO2) columns from the LOTOS-EUROS (Long Term Ozone Simulation-European Ozone Simulation) chemistry transport model (CTM) and from Ozone Monitoring Instrument (OMI) satellite retrievals, averaged for the summertime period (April-September) during 2013. Here we show that the top-down NOX emissions derived from LOTOS-EUROS for European urban areas agree well with the bottom-up NOX emissions from the MACC-III inventory data (R(exp 2) = 0.88) driving the CTM demonstrating the potential of this method. OMI top-down NOX emissions over the 23 European cities are generally lower compared with the MACC-III emissions and their correlation is slightly lower (R(exp 2) = 0.79). The uncertainty on the derived NO2 lifetimes and NOX emissions are on average ~55% for OMI and ~63% for LOTOS-EUROS data. The downwind NO2 plume method applied on both LOTOS-EUROS and OMI tropospheric NO2 columns allows to estimate NOX emissions from urban areas, demonstrating that this is a useful method for real-time updates of urban NOX emissions with reasonable accuracy.