Variability in Observation-Based Onroad Emission Constraints from a Near-Road Environment
Abstract
:1. Introduction
2. Methods
2.1. Las Vegas Near-Road Field Study
2.2. Data Screening Criteria
2.3. Ambient Data Analysis Methods
2.3.1. Upwind Monitor Data to Determine Cross-Road Gradient ∆CO:∆NOx
2.3.2. Regression Analyses for Determining Roadway ∆CO:∆NOx
2.4. Roadway CO:NOx from MOVES Emissions Model Simulations
3. Results
4. Discussion
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
Disclaimer
References
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Method | Error in Measurement Assumptions |
---|---|
Cross-road gradient | No instrument drift; differences in up-wind and down-wind monitors are solely due to emissions along I-15 |
OLS | σx = 0, or σx << σy |
Orthogonal Regression | σx / σy = 1 |
Method | Distance from Roadway (m) | Mean | Median | ||
---|---|---|---|---|---|
Scaling Ratio | p-Value * | Scaling Ratio | p-Value * | ||
Cross-road gradient | 25 | 0.94 | 0.43 | 0.96 | 0.92 |
115 | 0.90 | 0.25 | 0.99 | 0.62 | |
300 | 0.75 | 0.10 | 1.15 | 0.29 | |
OLS regression | 25 | 0.93 | 0.47 | 1.09 | 0.88 |
115 | 0.80 | 0.02 | 0.84 | 0.06 | |
300 | 0.73 | 4.59 × 10−3 | 0.90 | 0.04 | |
Orthogonal regression | 25 | 0.59 | 1.42 × 10−6 | 0.62 | 1.58 × 10−7 |
115 | 0.56 | 8.23 × 10−7 | 0.56 | 2.14 × 10−7 | |
300 | 0.53 | 2.83 × 10−6 | 0.67 | 1.36 × 10−8 |
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Simon, H.; Henderson, B.H.; Owen, R.C.; Foley, K.M.; Snyder, M.G.; Kimbrough, S. Variability in Observation-Based Onroad Emission Constraints from a Near-Road Environment. Atmosphere 2020, 11, 1243. https://doi.org/10.3390/atmos11111243
Simon H, Henderson BH, Owen RC, Foley KM, Snyder MG, Kimbrough S. Variability in Observation-Based Onroad Emission Constraints from a Near-Road Environment. Atmosphere. 2020; 11(11):1243. https://doi.org/10.3390/atmos11111243
Chicago/Turabian StyleSimon, Heather, Barron H. Henderson, R. Chris Owen, Kristen M. Foley, Michelle G. Snyder, and Sue Kimbrough. 2020. "Variability in Observation-Based Onroad Emission Constraints from a Near-Road Environment" Atmosphere 11, no. 11: 1243. https://doi.org/10.3390/atmos11111243