Reactive oxidized nitrogen speciation and partitioning in urban and rural New York State
Creators: name: Ninneman, Matthew
name: Marto, Joseph
name: Shaw, Stephanie
name: Edgerton, Eric
name: Blanchard, Charles
name: Schwab, James
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Space Science
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Cancer
subject: Plant Biology
subject: Computational Biology

description: This study examined reactive oxidized nitrogen (NO<sub>y</sub>) speciation and partitioning at one urban site, Queens College (QC) in New York City, and one rural site, Pinnacle State Park (PSP) in Addison, New York (NY) from September 2016 to August 2018 and June 2016 to September 2018, respectively. Oxides of nitrogen (NO<sub>x</sub>), nitric acid (HNO<sub>3</sub>), particle nitrate (pNO<sub>3</sub>), peroxy nitrates (PNs), alkyl nitrates (ANs), and NO<sub>y</sub> measurements were made at both sites. Across all seasons at QC, the median NO<sub>x</sub>, HNO<sub>3</sub>, pNO<sub>3</sub>, PNs, ANs, and NO<sub>y</sub> concentrations were 10.99, 0.49, 0.24, 0.62, 0.94, and 13.95 parts per billion (ppb), respectively. All-season median percent contributions of NO<sub>x</sub>, HNO<sub>3</sub>, pNO<sub>3</sub>, PNs, and ANs to the total NO<sub>y</sub> at QC were 77, 4, 2, 5, and 7%, respectively. Therefore, the sum of the individual NO<sub>y</sub> species (NO<sub>yi</sub> ≈ NO<sub>x</sub> + HNO<sub>3</sub> + pNO<sub>3</sub> + PNs + ANs) accounted for 95% of the total NO<sub>y</sub> at QC, which was well within measurement uncertainties. At PSP, the median NO<sub>x</sub>, HNO<sub>3</sub>, pNO<sub>3</sub>, PNs, ANs, and NO<sub>y</sub> concentrations were 0.65, 0.16, 0.12, 0.13, 0.18, and 1.56 ppb, respectively, over all seasons. The median percent contributions of NO<sub>x</sub>, HNO<sub>3</sub>, pNO<sub>3</sub>, PNs, and ANs to NO<sub>y</sub> over all seasons at PSP were 42, 10, 8, 9, and 12%, respectively. NO<sub>yi</sub> comprised 81% of NO<sub>y</sub> across all seasons at PSP, and deviations from 100% closure were generally within measurement uncertainties. Since both datasets yielded NO<sub>y</sub> budget closure results that were either fully or largely explained by the measurement uncertainties, the observed NO<sub>yi</sub> is likely representative of ambient NO<sub>y</sub> in urban and rural New York. The results have implications for understanding the fate of NO<sub>x</sub> emissions and their impact on local and regional air quality in urban and rural New York State. <i>Implications</i>: Continuous speciated and total reactive oxidized nitrogen (NO<sub>y</sub>) measurements were made in urban and rural New York from 2016 to 2018. Different NO<sub>y</sub> species have contrasting effects on the chemistry that impacts ozone (O<sub>3</sub>) and fine particulate matter (PM<sub>2.5</sub>) formation and concentrations. Since O<sub>3</sub> and PM<sub>2.5</sub> are regulated pollutants that have proven difficult to control, the results have implications for current and future air quality policy.