Daily Satellite Observations of Nitrogen Dioxide Air Pollution Inequality in New York City, New York and Newark, New Jersey: Evaluation and Application

Abstract

Urban air pollution disproportionately harms communities of color and low-income communities in the U.S. Intraurban nitrogen dioxide (NO 2 ) inequalities can be observed from space using the TROPOspheric Monitoring Instrument (TROPOMI). Past research has relied on time-averaged measurements, limiting our understanding of how neighborhood-level NO 2 inequalities co-vary with urban air quality and climate. Here, we use fine-scale (250 m × 250 m) airborne NO 2 remote sensing to demonstrate that daily TROPOMI observations resolve a major portion of census tract-scale NO 2 inequalities in the New York City−Newark urbanized area. Spatiotemporally coincident TRO-POMI and airborne inequalities are well correlated (r = 0.82−0.97), with slopes of 0.82−1.05 for relative and 0.76−0.96 for absolute inequalities for different groups. We calculate daily TROPOMI NO 2 inequalities over May 2018−September 2021, reporting disparities of 25−38% with race, ethnicity, and/or household income. Mean daily inequalities agree with results based on TROPOMI measurements oversampled to 0.01°× 0.01°to within associated uncertainties. Individual and mean daily TROPOMI NO 2 inequalities are largely insensitive to pixel size, at least when pixels are smaller than ∼60 km 2 , but are sensitive to low observational coverage. We statistically analyze daily NO 2 inequalities, presenting empirical evidence of the systematic overburdening of communities of color and low-income neighborhoods with polluting sources, regulatory ozone co-benefits, and worsened NO 2 inequalities and cumulative NO 2 and urban heat burdens with climate change.

Ethnoracial Disparities in Nitrogen Dioxide Pollution in the United States: Comparing Data Sets from Satellites, Models, and Monitors

“…Since its launch in 2017, TROPOMI has aided in studies probing NO X emission sources, 39,40 neighborhoodscale NO 2 variability, 41 and NO 2 inequality. 7,26 Finally, we considered annual average surface-level NO 2 concentrations from a 12 km × 12 km photochemical model, the EPA's Air QUAlity TimE Series Project ("EQUATES"), from which we obtain modeled concentrations for 2010− 2019. 42 2008, 2011, 2014, but mostly 2017), day-specific fires, and CMAQ runtime parametrizations of lightning NO X , soil NO X , biogenic VOCs, sea-spray, and wind-blown dust.…”

“…24 Spatially complete, high-resolution data sets are increasingly used to explore associations with health outcomes and identify communities overburdened by traffic-related air pollution. 3,5,6,10,25,26 Here, we compare NO 2 levels and ethnoracial NO 2 disparities derived using in situ monitors and three spatially complete data sets, which represent different families of tools (i.e., satellite data, statistical models, and photochemical models) that can be used to characterize NO 2 . Our goal is not to determine which family of tools or specific data set is most accurate, as the sparse network of in situ observations precludes this type of assessment, and the best data set for a particular application may depend not only on the data set's accuracy but also the specific research question.…”

Surf, Turf, and Above the Earth: Unmet Needs for Coastal Air Quality Science in the Planetary Boundary Layer (PBL)

“…However, relating the column amounts of pollutants to “nose‐level” or PBL concentrations, especially in coastal regions, remains a challenge due to the complexities of vertical distribution and often strong spatial and temporal variability in surface (land or ocean) reflectivity (Knepp et al., 2015; Kollonige et al., 2018; Szykman et al., 2019; Thompson et al., 2019, 2023; Tzortziou et al., 2015, 2018). However, continued work is moving toward evaluating and utilizing these satellite derived NO 2 products to the neighborhood scale (Demetillo et al., 2021; Dressel et al., 2022; Goldberg et al., 2021; Johnson et al., 2022; Judd et al., 2020) to better evaluate urban pollution and human health (Anenberg et al., 2022).…”

Environmental Science for the Betterment of All

“…This virtual issue highlights 40 articles from ES&T and ES&T Letters that document environmental injustice and its potential causes. These articles show that EJ issues span contexts, from rural 10,11 to urban. Inequities also occur at multiple spatial scales, from intraurban 12 to transnational.…”