GH54A-01 Policy and health relevant applications of NO2 remote sensing data

Nitrogen dioxide (NO₂) has been linked with adverse health effects and can sometimes be a tracer for other air pollutants (e.g., black carbon) and fossil-fuel greenhouse gas emissions. In this work, we demonstrate a variety of ways in which fine-scale remote sensing NO₂ measurements from recent instruments – GCAS, TROPOMI, and TEMPO – can be useful for policy and health relevant applications in the United States. First, we evaluate these products using ground-based instruments to determine any biases, and note that GCAS has little systematic bias, while TROPOMI has a systematic low bias in polluted areas that can be accounted for in application-based work. Using the GCAS instrument – acquiring column NO₂ measurements at sub-kilometer spatial resolution from an aircraft at 28,000 ft – we are able to identify neighborhoods in an urban area (Houston) in which inventory estimates of NOx emissions may be underestimated. Satellite-based instruments, such as TROPOMI and TEMPO have coarser spatial resolution measurements than GCAS, but continental to global coverage. We consider TROPOMI NO2 in the urban context, finding that TROPOMI can distinguish areas with higher NO2 near warehousing facilities, detect inequities among different marginalized and minoritized population groups, and be used to estimate health-relevant surface-level concentrations in global urban areas. TROPOMI is also helpful in tracking global near-real-time changes in NO₂ pollution over large regions. In post-pandemic years, we are documenting some unexpected changes in NO₂ trends over certain global regions. Finally, we give some insight in how TEMPO can be used synergistically with TROPOMI over North America to understand NOx emissions, NO₂ concentrations, and their health burden.