Multidecadal trends in ozone chemistry in the Baltimore-Washington Region

Roberts, Sandra J.; Salawitch, R. J.; Wolfe, G. M.; Marvin, Margaret R.; Canty, T. P.; Allen, D. J.; Hall, Dolly; Krask, D.; Dickerson, Russell R.

doi:10.1016/j.atmosenv.2022.119239

Cited by 5 publications

(12 citation statements)

References 96 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The meteorological situation matches the classic conceptual model of air stagnation accompanying higher temperature, ,− indicating a dominant role for local ozone production. Our findings resonate with previous studies emphasizing the impact of local industrial and traffic emissions and mesoscale meteorology (for example, boundary layer depth, humidity, air circulation) on surface ozone pollution over BAL/DC and the Chesapeake Bay. ,− …”

Section: Ozone Exceedance Versus Nonexceedance Dayssupporting

confidence: 91%

“…Based on HCHO/NO 2 -VCD Trop retrieved from GCAS/GeoTASO and TROPOMI and threshold values calculated in Jin et al., the NYC urban region falls in the NO x -saturated regime, whereas the BAL/DC region with lower summertime mean NO 2 VCD Trop is more sensitive to NO x . Earlier work also concludes that the NYC urban core remains NO x -saturated despite a general trend across the United States, including areas in the broader NYC metropolitan region, shifting urban chemistry toward NO x -sensitive in the past two decades. ,,− The BAL/DC region has also been identified as becoming dominated by the NO x -sensitive regime since the early 2000s . In any urban region that remains NO x -saturated, even though VOC emission reductions may help abate ozone locally, it would first be critical to determine whether local anthropogenic (for example, VOC from volatile chemical products − ) versus biogenic emissions dominate the VOC reactivity contributing to ozone formation, especially as biogenic VOC emissions are generally not controllable.…”

Section: Discussionmentioning

confidence: 99%

“… 50 , 51 , 123 − 125 The BAL/DC region has also been identified as becoming dominated by the NO x -sensitive regime since the early 2000s. 108 In any urban region that remains NO x -saturated, even though VOC emission reductions may help abate ozone locally, it would first be critical to determine whether local anthropogenic (for example, VOC from volatile chemical products 126 − 129 ) versus biogenic emissions dominate the VOC reactivity contributing to ozone formation, especially as biogenic VOC emissions are generally not controllable. In all cases, however, reducing NO x emissions will reduce the overall regional ozone production, and shift the urban core to NO x -sensitive with sufficient reductions.…”

Section: Discussionmentioning

confidence: 99%

“…Our findings resonate with previous studies emphasizing the impact of local industrial and traffic emissions and mesoscale meteorology (for example, boundary layer depth, humidity, air circulation) on surface ozone pollution over BAL/DC and the Chesapeake Bay. 22 , 106 − 108 …”

Section: Ozone Exceedance Versus Nonexceedance Daysmentioning

confidence: 99%

See 3 more Smart Citations

Investigating Changes in Ozone Formation Chemistry during Summertime Pollution Events over the Northeastern United States

Tao

Fiore

Jin

et al. 2022

Environ. Sci. Technol.

View full text Add to dashboard Cite

Understanding the local-scale spatial and temporal variability of ozone formation is crucial for effective mitigation. We combine tropospheric vertical column densities (VCDTrop) of formaldehyde (HCHO) and nitrogen dioxide (NO2), referred to as HCHO-VCDTrop and NO2-VCDTrop, retrieved from airborne remote sensing and the TROPOspheric Monitoring Instrument (TROPOMI) with ground-based measurements to investigate changes in ozone precursors and the inferred chemical production regime on high-ozone days in May–August 2018 over two Northeast urban domains. Over New York City (NYC) and Baltimore/Washington D.C. (BAL/DC), HCHO-VCDTrop increases across the domain, but higher NO2-VCDTrop occurs mainly in urban centers on ozone exceedance days (when maximum daily 8 h average (MDA8) ozone exceeds 70 ppb at any monitor in the region). The ratio of HCHO-VCDTrop to NO2-VCDTrop, proposed as an indicator of the sensitivity of local surface ozone production rates to its precursors, generally increases on ozone exceedance days, implying a transition toward a more NO x -sensitive ozone production regime that should lead to higher efficacy of NO x controls on the highest ozone days in NYC and BAL/DC. Warmer temperatures and enhanced influence from emissions in the local boundary layer on the high-ozone days are accompanied by slower wind speeds in BAL/DC but stronger, southwesterly winds in NYC.

show abstract

Section: Ozone Exceedance Versus Nonexceedance Dayssupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Ozone Exceedance Versus Nonexceedance Daysmentioning

confidence: 99%

See 2 more Smart Citations

Investigating Changes in Ozone Formation Chemistry during Summertime Pollution Events over the Northeastern United States

Tao

Fiore

Jin

et al. 2022

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Recent studies have shown that VOCs and NO x should be controlled simultaneously to reverse O 3 increases ( 13 , 14 ). These results concur with those of Pusede ( 15 ) and Roberts et al ( 16 ), who found that simultaneous VOC and NO x abatement could considerably mitigate the peak of O 3 production and prevent surface air quality deterioration.…”

Section: Introductionsupporting

confidence: 91%

Attributing Increases in Ozone to Accelerated Oxidation of Volatile Organic Compounds at Reduced Nitrogen Oxides Concentrations

Zhang

Jiang

et al. 2022

PNAS Nexus

View full text Add to dashboard Cite

Surface ozone (O3) is an important secondary pollutant affecting climate change and air quality in the atmosphere. Observations during the COVID-19 lockdown in urban China show that the co-abatement of nitrogen oxides (NOx) and volatile organic compounds (VOCs) caused winter ground-level O3 increases, but the chemical mechanisms involved are unclear. Here we report field observations in the Shanghai lockdown that reveals increasing photochemical formation of O3 from VOC oxidation with decreasing NOx. Analyses of the VOC profiles and NO/NO2 indicate that the O3 increase by the NOx reduction counteracted the O3 decrease throughthe VOC emission reduction in the VOC-limited region, and this may have been the main mechanism for this net O3 increase. The mechanism may have involved accelerated OH–HO2–RO2 radical cycling. The NOx reductions for increasing O3 production could explain why O3 increased from 2014 to 2020 in response to NOx emission reduction even as VOC emissions have essentially remained unchanged. Model simulations suggest that aggressive VOC abatement, particularly for alkenes and aromatics, should help reverse the long-term O3 increase under current NOx abatement conditions.

show abstract

Inferring Near-Surface Ozone Production Regimes: Challenges with using Satellite Retrievals over the Contiguous US

Singh,

Ring,

et al. 2024

Preprint

View full text Add to dashboard Cite

Surface ozone regulation policies rely heavily on air quality models, such as CAMx, as important guiding tools. Comparison with observations is crucial to validating a model’s ability to represent ozone production chemistry. Identifying factors influencing surface ozone formation is complicated because ozone photochemical production rates are non-linearly dependent on concentrations of precursors such as nitrogen oxides (NOx) and volatile organic compounds (VOCs). We compare ozone production regimes (OPRs) identified from satellite observations and model simulations, as defined by the ratio of column formaldehyde to nitrogen dioxide (FNR, HCHO/NO2). We perform CAMx simulations for June-July-August 2016 over the Contiguous United States (CONUS) and compared these outputs against two OMI NO2and HCHO retrievals. Our analysis spans diurnal and altitudinal variations of OPRs, offering important insights for effective policy formulation. At the time of the OMI overpass (~1:30 PM LT), OPR is NOx-limited over most of the CONUS, as determined from OMI column ratios. Analysis of CAMx column ratios shows similar results. In contrast, more regions are VOC-limited when we constrain our ratio to within the Planetary Boundary Layer (PBL). In the morning (~9 AM LT), the CAMx PBL column ratios shift towards VOC-limited regime. We highlight areas of the CONUS for which satellite measurements of FNR may not be an accurate indicator of near-surface OPRs. Air quality regulations based on satellite observations should consider the diurnal variations of surface OPRs and assess how well their ratios represent near-surface OPR. Our results have implications for interpretation of TEMPO data for policy relevant applications.

show abstract

Multidecadal trends in ozone chemistry in the Baltimore-Washington Region

Cited by 5 publications

References 96 publications

Investigating Changes in Ozone Formation Chemistry during Summertime Pollution Events over the Northeastern United States

Investigating Changes in Ozone Formation Chemistry during Summertime Pollution Events over the Northeastern United States

Attributing Increases in Ozone to Accelerated Oxidation of Volatile Organic Compounds at Reduced Nitrogen Oxides Concentrations

Inferring Near-Surface Ozone Production Regimes: Challenges with using Satellite Retrievals over the Contiguous US

Contact Info

Product

Resources

About