Photochemical indicators of ozone sensitivity: application in the Pearl River Delta, China

Abstract

The distribution of NO_x- and VOC-sensitive regimes in the PRD are identified.

The effectiveness of six popular chemical indicators for discriminating O₃ sensitivity regimes is evaluated.

Threshold levels for HCHO/NO_y, H₂O₂/HNO₃, O₃/NO_y, O₃/NO_z, O₃/HNO₃ were derived and verified.

The indicators H₂O₂/HNO₃ and H₂O₂/NO_z performed best and maintained relatively stable threshold levels.

Surface O₃ production has a highly nonlinear relationship with its precursors. The spatial and temporal heterogeneity of O₃-NO_x-VOC-sensitivity regimes complicates the control- decision making. In this paper, the indicator method was used to establish the relationship between O₃ sensitivity and assessment indicators. Six popular ratios indicating ozone-precursor sensitivity, HCHO/NO_y, H₂O₂/HNO₃, O₃/NO_y, O₃/NO_z, O₃/HNO₃, and H₂O₂/NO_z, were evaluated based on the distribution of NO_x- and VOC-sensitive regimes. WRF-Chem was used to study a serious ozone episode in fall over the Pearl River Delta (PRD). It was found that the south-west of the PRD is characterized by a VOC-sensitive regime, while its north-east is NO_x-sensitive, with a sharp transition area between the two regimes. All indicators produced good representations of the elevated ozone hours in the episode on 6 November 2009, with H₂O₂/HNO₃ being the best indicator. The threshold sensitivity levels for HCHO/NO_y, H₂O₂/HNO₃, O₃/NO_y, O₃/NO_z, O₃/HNO₃, and H₂O₂/NO_z were estimated to be 0.41, 0.55, 10.2, 14.0, 19.1, and 0.38, respectively. Threshold intervals for the indicators H₂O₂/HNO₃, O₃/NO_y, O₃/NO_z, O₃/HNO₃, and H₂O₂/NO_z were able to identify more than 95% of VOC- and NO_x-sensitive grids. The ozone episode on 16 November 16 2008 was used to independently verify the results, and it was found that only H₂O₂/HNO₃ and H₂O₂/NO_z were able to differentiate the ozone sensitivity regime well. Hence, these two ratios are suggested as the most appropriate indicators for identifying fall ozone sensitivity in the PRD. Since the species used for indicators have seasonal variation, the utility of those indicators for other seasons should be investigated in the future work.

Graphical abstract

Keywords

Ozone / Pearl River Delta (PRD) / Sensitivity regime / Photochemical indicator / Threshold levels

References

[1] Situ S P, Guenther A, Wang X M, Jiang X, Turnipseed A, Wu Z Y, Bai J H, Wang X. Impacts of seasonal and regional variability in biogenic VOC emissions on surface ozone in the Pearl River Delta region, China. Atmospheric Chemistry and Physics, 2013, 13(23): 11803–11817

[2] Jin X M, Holloway T. Spatial and temporal variability of ozone sensitivity over China observed from the Ozone Monitoring Instrument. Journal of Geophysical Research, D, Atmospheres, 2015, 120(14): 7229–7246

[3] Song J, Lei W, Bei N, Zavala M, de Foy B, Volkamer R, Cardenas B, Zheng J, Zhang R, Molina L T. Ozone response to emission changes: a modeling study during the MCMA-2006/MILAGRO Campaign. Atmospheric Chemistry and Physics, 2010, 10(8): 3827–3846

[4] Zhang Y H, Su H, Zhong L J, Cheng Y F, Zeng L M, Wang X S, Xiang Y R, Wang J L, Gao D F, Shao M, Liu S C. Regional ozone pollution and observation-based approach for analyzing ozone-precursor relationship during the PRIDE-PRD2004 campaign. Atmospheric Environment, 2008, 42(25): 6203–6218

[5] Chou C CK, Tsai C Y, Shiu C J, Liu S C, Zhu T.Measurement of NOy during campaign of air quality research in Beijing 2006(CAREBeijing-2006): implications for the ozone production efficiency of NOx. Journal of Geophysical Research-Atmospheres, 2009, 114(D00G01)

[6] Shao M, Zhang Y H, Zeng L M, Tang X Y, Zhang J, Zhong L J, Wang B G. Ground-level ozone in the Pearl River Delta and the roles of VOC and NO_x in its production. Journal of Environmental Management, 2009, 90(1): 512–518

[7] Li Y, Lau A K H, Fung J C H, Zheng J Y, Liu S C. Importance of NO_x control for peak ozone reduction in the Pearl River Delta region. Journal of Geophysical Research, D, Atmospheres, 2013, 118(16): 9428–9443

[8] Xing J, Wang S X, Jang C, Zhu Y, Hao J M. Nonlinear response of ozone to precursor emission changes in China: a modeling study using response surface methodology. Atmospheric Chemistry and Physics, 2011, 11(10): 5027–5044

[9] Wang X M, Carmichael G, Chen D L, Tang Y H, Wang T J. Impacts of different emission sources on air quality during March 2001 in the PRD (PRD) region. Atmospheric Environment, 2005, 39(29): 5227–5241

[10] Lam K S, Wang T J, Wu C L, Li Y S. Study on an ozone episode in hot season in Hong Kong and transboundary air pollution over PRD region of China. Atmospheric Environment, 2005, 39(11): 1967–1977

[11] Wang X, Zhang Y, Hu Y, Zhou W, Lu K, Zhong L, Zeng L, Shao M, Hu M, Russell A G. Process analysis and sensitivity study of regional ozone formation over the PRD, China, during the PRIDE-PRD2004 campaign using the Community Multiscale Air Quality modeling system. Atmospheric Chemistry and Physics, 2010, 10(9): 4423–4437

[12] Wang X S, Zhang Y H, Hu Y T, Zhou W, Zeng L M, Hu M, Cohan D S, Russell A G. Decoupled direct sensitivity analysis of regional ozone pollution over the PRD during the PRIDE-PRD2004 campaign. Atmospheric Environment, 2011, 45(28): 4941–4949

[13] Jiménez P, Baldasano J M. Ozone response to precursor controls in very complex terrains: use of photochemical indicators to assess O₃-NO_x-VOC sensitivity in the northeastern Iberian Peninsula. Journal of Geophysical Research: Atmospheres (1984–2012), 2004, 109(D20)

[14] Peng Y P, Chen K S, Lai C H, Lu P J, Kao J H. Concentrations of H₂O₂ and HNO₃ and O₃-VOC-NO_x sensitivity in ambient air in southern Taiwan. Atmospheric Environment, 2006, 40(35): 6741–6751

[15] Tie X X, Madronich S, Li G H, Ying Z M, Zhang R Y, Garcia A R, Lee-Taylor J, Liu Y B. Characterizations of chemical oxidants in Mexico City: a regional chemical dynamical model (WRF-Chem) study. Atmospheric Environment, 2007, 41(9): 1989–2008

[16] Sillman S, West J J. Reactive nitrogen in Mexico City and its relation to ozone-precursor sensitivity: results from photochemical models. Atmospheric Chemistry and Physics, 2009, 9(11): 3477–3489

[17] Tie X, Geng F, Guenther A, Cao J, Greenberg J, Zhang R, Apel E, Li G, Weinheimer A, Chen J, Cai C. Megacity impacts on regional ozone formation: observations and WRF-Chem modeling for the MIRAGE-Shanghai field campaign. Atmospheric Chemistry and Physics, 2013, 13(11): 5655–5669

[18] Milford J B, Gao D F, Sillman S, Blossey P, Russell A G.Total reactive nitrogen (NO_y) as an indicator of the sensitivity of ozone to reductions in hydrocarbon and NO_x emissions. Journal of Geophysical Research: Atmospheres (1984–2012), 1994, 99(D2): 3533–3542

[19] Sillman S.The use of NO_y, H₂O₂, and HNO₃ as indicators for ozone-NO_x-hydrocarbon sensitivity in urban locations. Journal of Geophysical Research, 1995, 100(D7): 14175–14188

[20] Wang Z, Shao M, Chen L, Tao M H, Zhong L J, Chen D H, Fan M, Wang Y, Wang X H. Space view of the decadal variation for typical air pollutants in the Pearl River Delta (PRD) region in China. Frontiers of Environmental Science & Engineering, 2016, 10(5): 1–14

[21] Parrish D D, Xu J, Croes B, Shao M. Air quality improvement in Los Angeles- perspectives for developing cities. Frontiers of Environmental Science & Engineering, 2016, 10(5): 1–13

[22] Zheng J Y, Zhang L J, Che W W, Zheng Z Y, Yin S S. A highly resolved temporal and spatial air pollutant emission inventory for the PRD region, China and its uncertainty assessment. Atmospheric Environment, 2009a, 43(32): 5112–5122

[23] Zheng J Y, Zhang L J, Zhong L J, Wang Z L. Area source emission inventory of air pollutant and its spatial distribution characteristics in PRD. China Environmental Science, 2009b, 29(5): 455–460 (in Chinese)

[24] Zheng J Y, Shao M, Che W W, Zhang L J, Zhong L J, Zhang Y H, Streets D. Speciated VOC Emission Inventory and Spatial Patterns of Ozone Formation Potential in the Pearl River Delta, China. Environmental Science & Technology, 2009c, 43(22): 8580–8586

[25] Guenther A, Karl T, Harley P, Wiedinmyer C, Palmer P I, Geron C. Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature). Atmospheric Chemistry and Physics, 2006, 6(11): 3181–3210

[26] Liang J, Jackson B, Kaduwela A. Evaluation of the ability of indicator species ratios to determine the sensitivity of ozone to reductions in emissions of volatile organic compounds and oxides of nitrogen in northern California. Atmospheric Environment, 2006, 40(27): 5156–5166

[27] Castell N, Stein A F, Mantilla E, Salvador R, Millán M. Evaluation of the use of photochemical indicators to assess ozone-NO_x-VOC sensitivity in the Southwestern Iberian Peninsula. Journal of Atmospheric Chemistry, 2009, 63(1): 73–91

[28] Chang M, Fan S F, Wang X M. Impact of refined land-cover data on WRF performance over the Pearl River Delta region, China. Acta Scientiae Circumstantiae, 2014, 34(8): 1922–1933 (in Chinese)

[29] Andreani-Aksoyoglu S, Lu C H, Keller J, Prevot A S H, Chang J S. Variability of indicator values for ozone production sensitivity: a model study in Switzerland and San Joaquin Valley (California). Atmospheric Environment, 2001, 35(32): 5593–5604

[30] Xu X B, Ge B Z, Lin W L. Progresses in the Research of Ozone Production Efficiency (OPE). Advances in Earth Science, 2009, 24(8): 845–853 (in Chinese)

[31] Sillman S. The relation between ozone, NO_x and hydrocarbons in urban and polluted rural environments. Atmospheric Environment, 1999, 33(12): 1821–1845

[32] Zhang Y, Bischof C H, Easter R C, Wu P T. Sensitivity analysis of photochemical indicators for O₃ chemistry using automatic differentiation. Journal of Atmospheric Chemistry, 2005, 51(1): 1–41

Acknowledgements

Financial supports from the Special Fund for Meteorological-scientific Research in the Public Interest of China (No. GYHY201406031), National Science Foundation for Distinguished Young Scholars (No. 41425020), National Key Technology Research and Development Program of the Ministry of Science and Technology of China (Grant No. 2014BAC21B02), Foshan Environmental Protection Bureau Project (GDJAFS 2015046G) are gratefully acknowledged by the authors. We acknowledge Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase) and National Supercomputing Center in Guangzhou (NSCC-GZ). At the same time, we are grateful for Guangzhou Meteorological Service for the Meteorological data, and Guangzhou Environmental Monitoring for air quality observational data.

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2016 Higher Education Press and Springer-Verlag Berlin Heidelberg