8A.5 Policy-relevant Applications of OMI NO2 and TROPOMI NO2 Satellite Data: Estimating NOX Emissions and Inferring CO2 Emissions

Wednesday, 15 January 2020: 9:30 AM
206B (Boston Convention and Exhibition Center)
Daniel Goldberg, ANL, Lemont, IL; George Washington Univ., Washington, DC; and Z. Lu, D. G. Streets, B. De Foy, D. Griffin, C. McLinden, F. Liu, L. N. Lamsal, T. Oda, H. Eskes, B. Duncan, and N. A. Krotkov

To better estimate satellite-based NO2 column densities in urban areas and in areas with power plants, we use regional chemical transport models to re-calculate tropospheric air mass factors and tropospheric NO2 vertical columns for the OMI and TROPOMI NO2 products in North America. For both satellite products, tropospheric columns increase by up to 50% in city centers, and decrease by ~20% in the rural areas outside of urban areas when compared to the operational products. The enhanced products show better agreement with the Pandora NO2 and aircraft measurements acquired during NASA field campaigns, signifying that the enhanced products are a better indicator of surface concentrations and emissions than the operational products. We use these enhanced OMI NO2 and TROPOMI NO2 products to estimate NOX emissions and infer CO2 emissions. A statistical model is fit to an oversampling of rotated NO2 plumes observed from OMI and TROPOMI, and is used to calculate top-down NOX emissions. These top-down emissions are also compared to each other for the summer of 2018. We then apply city-specific NOx-to-CO2 ratios from bottom-up emission inventories to the top-down NOx emissions to develop first-order approximations of CO2 emissions from fossil-fuel combustion. For 2017, we report annual fossil-fuel CO2 emissions to be: Los Angeles 113 ± 49 Tg/yr; New York City 144 ± 62 Tg/yr; and Chicago 55 ± 24 Tg/yr. A study in the Los Angeles area, using independent methods, reported a 2013 – 2016 average CO2 emissions rate of 104 Tg/yr and 120 Tg/yr, which suggests that the emissions rates from our method are in good agreement with other studies’ top-down estimates. Future work will focus on using the simultaneous measurements from both instruments to build upon OMI’s legacy of providing policy-relevant information to regulators assessing the effectiveness of air pollution reduction strategies.
- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner