Dressel Isabella M, Zhang Sixuan, Demetillo Mary Angelique G, Yu Shan, Fields Kimberly, Judd Laura M, Nowlan Caroline R, Sun Kang, Kotsakis Alexander, Turner Alexander J, Pusede Sally E
Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia 22904, United States.
NASA Langley Research Center, Hampton, Virginia 23681, United States.
ACS EST Air. 2024 Jul 30;1(9):973-988. doi: 10.1021/acsestair.4c00009. eCollection 2024 Sep 13.
In Houston, Texas, nitrogen dioxide (NO) air pollution disproportionately affects Black, Latinx, and Asian communities, and high ozone (O) days are frequent. There is limited knowledge of how NO inequalities vary in urban air quality contexts, in part from the lack of time-varying neighborhood-level NO measurements. First, we demonstrate that daily TROPOspheric Monitoring Instrument (TROPOMI) NO tropospheric vertical column densities (TVCDs) resolve a major portion of census tract-scale NO inequalities in Houston, comparing NO inequalities based on TROPOMI TVCDs and spatiotemporally coincident airborne remote sensing (250 m × 560 m) from the NASA TRacking Aerosol Convection ExpeRiment-Air Quality (TRACER-AQ). We further evaluate the application of daily TROPOMI TVCDs to census tract-scale NO inequalities (May 2018-November 2022). This includes explaining differences between mean daily NO inequalities and those based on TVCDs oversampled to 0.01° × 0.01° and showing daily NO column-surface relationships weaken as a function of observation separation distance. Second, census tract-scale NO inequalities, city-wide high O, and mesoscale airflows are found to covary using principal component and cluster analysis. A generalized additive model of O mixing ratios versus NO inequalities reproduces established nonlinear relationships between O production and NO concentrations, providing observational evidence that neighborhood-level NO inequalities and O are coupled. Consequently, emissions controls specifically in Black, Latinx, and Asian communities will have co-benefits, reducing both NO disparities and high O days city wide.
在得克萨斯州休斯敦，二氧化氮（NO）空气污染对黑人、拉丁裔和亚裔社区的影响尤为严重，高臭氧（O）天数频繁。对于城市空气质量背景下NO不平等现象如何变化，人们了解有限，部分原因是缺乏随时间变化的社区层面NO测量数据。首先，我们证明，每日对流层监测仪器（TROPOMI）的NO对流层垂直柱密度（TVCDs）解决了休斯敦人口普查区尺度上大部分的NO不平等问题，我们基于TROPOMI TVCDs以及来自美国国家航空航天局对流层气溶胶追踪实验-空气质量（TRACER-AQ）的时空重合机载遥感（250米×560米）数据比较了NO不平等情况。我们进一步评估了每日TROPOMI TVCDs在人口普查区尺度NO不平等问题上的应用（2018年5月至2022年11月）。这包括解释每日平均NO不平等与基于过采样至0.01°×0.01°的TVCDs的NO不平等之间的差异，并表明每日NO柱面关系会随着观测距离的增加而减弱。其次，通过主成分分析和聚类分析发现，人口普查区尺度的NO不平等、全市范围的高O以及中尺度气流是共同变化的。O混合比与NO不平等的广义相加模型再现了O生成与NO浓度之间已确立的非线性关系，提供了社区层面NO不平等与O相互关联的观测证据。因此，专门针对黑人、拉丁裔和亚裔社区的排放控制将产生协同效益，减少全市范围内的NO差距和高O天数。
