References

ACPD

Atmospheric Chemistry and Physics Discussions

ACPD

1680-7375

Copernicus GmbH

Göttingen, Germany

10.5194/acpd-12-4679-2012

Summertime photochemistry during CAREBeijing-2007: RO x budgets and O3 formation

Liu

¹ Wang

¹ Gu

¹ Zhao

¹ ⁵ Huey

L. G.

¹ Stickel

¹ Liao

¹ Shao

² Zhu

² Zeng

² Amoroso

³ Costabile

³ Chang

C.-C.

⁴ Liu

S.-C.

⁴

School of Earth and Atmospheric Science, Georgia Institute of Technology, Atlanta, USA

College of Environmental Sciences and Engineering, Peking University, Beijing, China

Institute for Atmospheric Pollution, National Research Council (CNR-IIA), Rome, Italy

Research Center for Environmental Changes (RCEC), Academic Sinica, Taipei, China

now at: the Pacific Northwest National Laboratory, Richland, Washington, USA

09 02 2012

12 2 4679 4717

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We analyze summertime photochemistry near the surface over Beijing, China, using a 1-D photochemical model (Regional chEmical and trAnsport Model, REAM-1D) constrained by in situ observations, focusing on the budgets of ROx (OH + HO2 + RO2) radicals and O3 formation. The daytime average of total ROx primary production rate in Beijing is ~6.6 ppbv h−1, among the highest found in urban atmospheres. The largest primary ROx source in Beijing is photolysis of oxygenated volatile organic compounds (OVOCs), which produces HO2 and RO2 at average daytime rates of 2.5 ppbv h−1 and 1.7 ppbv h−1, respectively. Photolysis of excess HONO from the unknown heterogeneous source is a predominant primary OH source at 2.2 ppbv h−1, much larger than that of O1D + H2O (0.4 ppbv h−1). The largest ROx sink is via OH + NO2 reaction (1.6 ppbv h−1), followed by formation of RO2NO2 (1.0 ppbv h−1) and RONO2 (0.7 ppbv h−1). Due to the large aerosol surface area, aerosol uptake of HO2 appears to be another important radical sink, although the estimate of its magnitude is highly variable depending on the reactive uptake coefficient value used. The daytime average O3 production and loss rates are 32 ppbv h−1 and 6.2 ppbv h−1, respectively. Assuming NO2 to be the source of excess HONO, the NO2 to HONO transformation leads to significant O3 loss and reduction of its lifetime. Our observation-based modeling analyses suggest that VOCs and heterogeneous reactions (e.g. HONO formation and aerosol uptake HO2) play major roles in the primary radical budget and O3 formation in Beijing. Among the VOC precursors for OVOCs, which strongly affect ROx budgets and O3 formation, aromatics are the largest contributor. One important ramification is that O3 production is neither NOx nor VOC limited, but in a transition regime, where reduction of either NOx or VOCs could result in reduction of O3 production. The transition regime implies more flexibility in the O3 control strategies than a binary system of either NOx or VOC limited regime. Further research on the spatial extent of the transition regime over the polluted eastern China is critically important for controlling regional O3 pollution.

References 1

Acker, K., Febo, A., Trick, S., Perrino, C., Bruno, P., Wiesen, P., Moller, D., Wieprecht, W., Auel, R., Giusto, M., Geyer, A., Platt, U., and Allegrini, I.: Nitrous acid in the urban area of Rome, Atmos. Environ., 40, 3123–3133, http://dx.doi.org/10.1016/j.atmosenv.2006.01.028doi:10.1016/j.atmosenv.2006.01.028, 2006.

Amoroso, A., Beine, H. J., Sparapani, R., Nardino, M., and Allegrini, I.: Observation of coinciding arctic boundary layer ozone depletion and snow surface emissions of nitrous acid, Atmos. Environ., 40, 1949–1956, 2006.

An, J. L., Zhang, W., and Qu, Y.: Impacts of a strong cold front on concentrations of HONO, HCHO, O3, and NO2 in the heavy traffic urban area of Beijing, Atmos. Environ., 43, 3454–3459, http://dx.doi.org/10.1016/j.atmosenv.2009.04.052doi:10.1016/j.atmosenv.2009.04.052, 2009.

Carter, W. P. L.: Development of the SAPRC–07 chemical mechanism and upadated ozone reactivity scales. Final Report to the California Air Resources Board Contract no 03–318, 2009.

Cermak, J. and Knutti, R.: Beijing Olympics as an aerosol field experiment, Geophys. Res. Lett., 36, L10806, http://dx.doi.org/10.1029/2009gl038572doi:10.1029/2009gl038572, 2009.

Chan, C. K. and Yao, X.: Air pollution in mega cities in China, Atmos. Environ., 42, 1–42, http://dx.doi.org/10.1016/j.atmosenv.2007.09.003doi:10.1016/j.atmosenv.2007.09.003, 2008.

Choi, Y., Wang, Y. H., Zeng, T., Martin, R. V., Kurosu, T. P., and Chance, K.: Evidence of lightning NOx and convective transport of pollutants in satellite observations over North America, Geophys. Res. Lett., 32, L02805, http://dx.doi.org/10.1029/2004gl021436doi:10.1029/2004gl021436, 2005.

Choi, Y., Wang, Y., Zeng, T., Cunnold, D., Yang, E. S., Martin, R., Chance, K., Thouret, V., and Edgerton, E.: Springtime transitions of NO2, CO, and O3 over North America: Model evaluation and analysis, J. Geophys. Res.-Atmos., 113, D20311, http://dx.doi.org/10.1029/2007jd009632doi:10.1029/2007jd009632, 2008a.

Choi, Y., Wang, Y. H., Yang, Q., Cunnold, D., Zeng, T., Shim, C., Luo, M., Eldering, A., Bucsela, E., and Gleason, J.: Spring to summer northward migration of high O-3 over the western North Atlantic, Geophys. Res. Lett., 35, L04818, http://dx.doi.org/10.1029/2007gl032276doi:10.1029/2007gl032276, 2008b.

Chou, C. C. K., Tsai, C. Y., Shiu, C. J., Liu, S. C., and Zhu, T.: Measurement of NOy during Campaign of Air Quality Research in Beijing 2006.

CAREBeijing-2006: Implications for the ozone production efficiency of NOx, J. Geophys. Res.-Atmos., 114, D00g01, http://dx.doi.org/10.1029/2008jd010446doi:10.1029/2008jd010446, 2009.

Chou, C. C. K., Tsai, C. Y., Chang, C. C., Lin, P. H., Liu, S. C., and Zhu, T.: Photochemical production of ozone in Beijing during the 2008 Olympic Games, Atmos. Chem. Phys., 11, 9825–9837, http://dx.doi.org/10.5194/acp-11-9825-2011doi:10.5194/acp-11-9825-2011, 2011.

Costabile, F., Amoroso, A., and Wang, F.: Sub-mu m particle size distributions in a suburban Mediterranean area. Aerosol populations and their possible relationship with HONO mixing ratios, Atmos. Environ., 44, 5258–5268, http://dx.doi.org/10.1016/j.atmosenv.2010.08.018doi:10.1016/j.atmosenv.2010.08.018, 2010.

Daum, P. H., Kleinman, L. I., Imre, D. G., Nunnermacker, L. J., Lee, Y.-N., Springston, S. R., Newman, L., and Weinstein-Lloyd, J.: Analysis of the processing of Nashville urban emissions on July 3 and July 18, 1995, J. Geophys. Res., 105, 9155–9164, 2000.

Dusanter, S., Vimal, D., Stevens, P. S., Volkamer, R., Molina, L. T., Baker, A., Meinardi, S., Blake, D., Sheehy, P., Merten, A., Zhang, R., Zheng, J., Fortner, E. C., Junkermann, W., Dubey, M., Rahn, T., Eichinger, B., Lewandowski, P., Prueger, J., and Holder, H.: Measurements of OH and HO2 concentrations during the MCMA-2006 field campaign – Part 2: Model comparison and radical budget, Atmos. Chem. Phys., 9, 6655–6675, http://dx.doi.org/10.5194/acp-9-6655-2009doi:10.5194/acp-9-6655-2009, 2009.

Elshorbany, Y. F., Kurtenbach, R., Wiesen, P., Lissi, E., Rubio, M., Villena, G., Gramsch, E., Rickard, A. R., Pilling, M. J., and Kleffmann, J.: Oxidation capacity of the city air of Santiago, Chile, Atmos. Chem. Phys., 9, 2257–2273, http://dx.doi.org/10.5194/acp-9-2257-2009doi:10.5194/acp-9-2257-2009, 2009.

Emmerson, K. M., Carslaw, N., Carpenter, L. J., Heard, D. E., Lee, J. D., and Pilling, M. J.: Urban atmospheric chemistry during the PUMA campaign 1: Comparison of modelled OH and HO2 concentrations with measurements, J. Atmos. Chem., 52, 143–164, http://dx.doi.org/10.1007/s10874-005-1322-3doi:10.1007/s10874-005-1322-3, 2005a.

Emmerson, K. M., Carslaw, N., and Pilling, M. J.: Urban atmospheric chemistry during the PUMA campaign 2: Radical budgets for OH, HO2 and RO2, J. Atmos. Chem., 52, 165–183, http://dx.doi.org/10.1007/s10874-005-1323-2doi:10.1007/s10874-005-1323-2, 2005b.

Farmer, D. K., Perring, A. E., Wooldridge, P. J., Blake, D. R., Baker, A., Meinardi, S., Huey, L. G., Tanner, D., Vargas, O., and Cohen, R. C.: Impact of organic nitrates on urban ozone production, Atmos. Chem. Phys., 11, 4085–4094, http://dx.doi.org/10.5194/acp-11-4085-2011doi:10.5194/acp-11-4085-2011, 2011.

Haagen-Smit, A. J. and Fox, M. M.: Photochemical ozone formation with hydrocarbons and automobile exhaust, Japca J. Air Waste Ma., 4, 105–109, 1954.

Hecobian, A., Liu, Z., Hennigan, C. J., Huey, L. G., Jimenez, J. L., Cubison, M. J., Vay, S., Diskin, G. S., Sachse, G. W., Wisthaler, A., Mikoviny, T., Weinheimer, A. J., Liao, J., Knapp, D. J., Wennberg, P. O., K�rten, A., Crounse, J. D., Clair, J. St., Wang, Y., and Weber, R. J.: Comparison of chemical characteristics of 495 biomass burning plumes intercepted by the NASA DC-8 aircraft during the ARCTAS/CARB-2008 field campaign, Atmos. Chem. Phys., 11, 13325–13337, http://dx.doi.org/10.5194/acp-11-13325-2011doi:10.5194/acp-11-13325-2011, 2011.

Ho, S. S. H., and Yu, J. Z.: Determination of airborne carbonyls: Comparison of a thermal desorption/GC method with the standard DNPH/HPLC method, Environ. Sci. Technol., 38, 862–870, http://dx.doi.org/10.1021/es034795wdoi:10.1021/es034795w, 2004.

Hofzumahaus, A., Rohrer, F., Lu, K. D., Bohn, B., Brauers, T., Chang, C. C., Fuchs, H., Holland, F., Kita, K., Kondo, Y., Li, X., Lou, S. R., Shao, M., Zeng, L. M., Wahner, A., and Zhang, Y. H.: Amplified Trace Gas Removal in the Troposphere, Science, 324, 1702–1704, http://dx.doi.org/10.1126/science.1164566doi:10.1126/science.1164566, 2009.

Jenkin, M. E. and Clemitshaw, K. C.: Ozone and other secondary photochemical pollutants: chemical processes governing their formation in the planetary boundary layer, Atmos. Environ., 34, 2499–2527, http://dx.doi.org/10.1016/s1352-2310(99)00478-1doi:10.1016/s1352-2310(99)00478-1, 2000.

Kanaya, Y., Fukuda, M., Akimoto, H., Takegawa, N., Komazaki, Y., Yokouchi, Y., Koike, M., and Kondo, Y.: Urban photochemistry in central Tokyo: 2. Rates and regimes of oxidant (O3 + NO2) production, J. Geophys. Res.-Atmos., 113, D06301, http://dx.doi.org/10.1029/2007jd008671doi:10.1029/2007jd008671, 2008.

Kanaya, Y., Pochanart, P., Liu, Y., Li, J., Tanimoto, H., Kato, S., Suthawaree, J., Inomata, S., Taketani, F., Okuzawa, K., Kawamura, K., Akimoto, H., and Wang, Z. F.: Rates and regimes of photochemical ozone production over Central East China in June 2006: a box model analysis using comprehensive measurements of ozone precursors, Atmos. Chem. Phys., 9, 7711–7723, http://dx.doi.org/10.5194/acp-9-7711-2009doi:10.5194/acp-9-7711-2009, 2009.

Kleffmann, J.: Daytime sources of nitrous acid (HONO) in the atmospheric boundary layer, ChemPhysChem, 8, 1137-1144, 10.1002/cphc.200700016, 2007.

Kleinman, L. I., Daum, P. H., Lee, J. H., Lee, Y.-N., Nunnermacker, L. J., Springston, S. R., Newman, L., Weinstein-Lloyd, J., and Sillman, S.: Dependence of ozone production on NO and hydrocarbons in the troposphere, Geophys. Res. Lett., 24, 2299–2302, 1997.

Lei,~W., de~Foy,~B., Zavala,~M., Volkamer,~R., and Molina,~L T.: Characterizing ozone production in the Mexico City Metropolitan Area: a case study using a chemical transport model, Atmos. Chem. Phys., 7, 1347–1366, http://dx.doi.org/10.5194/acp-7-1347-2007doi:10.5194/acp-7-1347-2007, 2007.

Liu, S. C., Trainer, M., Fehsenfeld, F. C., Parrish, D. D., Williams, E. J., Fahey, D. W., Hübler, G., and Murphy,~P. C.: Ozone Production in the Rural Troposphere and the Implications for Regional and Global Ozone Distributions,~J. Geophys. Res.,~92, 4191–4207, 1987.

Liu, Z., Wang, Y. H., Gu, D. S., Zhao, C., Huey, L. G., Stickel, R., Liao, J., Shao, M., Zhu, T., Zeng, L. M., Liu, S. C., Chang, C. C., Amoroso, A., and Costabile, F.: Evidence of Reactive Aromatics As a Major Source of Peroxy Acetyl Nitrate over China, Environ. Sci. Technol., 44, 7017–7022, http://dx.doi.org/10.1021/es1007966doi:10.1021/es1007966, 2010.

Lou, S., Holland, F., Rohrer, F., Lu, K., Bohn, B., Brauers, T., Chang, C. C., Fuchs, H., Häseler, R., Kita, K., Kondo, Y., Li, X., Shao, M., Zeng, L., Wahner, A., Zhang, Y., Wang, W., and Hofzumahaus, A.: Atmospheric OH reactivities in the Pearl River Delta – China in summer 2006: measurement and model results, Atmos. Chem. Phys., 10, 11243–11260, http://dx.doi.org/10.5194/acp-10-11243-2010doi:10.5194/acp-10-11243-2010, 2010.

%Lu, K. D., Rohrer, F., Holland, F., Fuchs, H., Bohn, B., Brauers, T., Chang, %C. C., Häseler, R., Hu, M., Kita, K., Kondo, Y., Li, X., Lou, S. R., %Nehr, S., Shao, M., Zeng, L. M., Wahner, A., Zhang, Y. H., and Hofzumahaus, %A.: Observation and modelling of OH and HO2 concentrations in the Pearl %River Delta 2006: a missing OH source in a VOC rich atmosphere, Atmos. Chem. %Phys. Discuss., 11, 11311-11378, 10.5194/acpd-11-11311-2011, 2011. Lu, K. D., Rohrer, F., Holland, F., Fuchs, H., Bohn, B., Brauers, T., Chang, C. C., Häseler, R., Hu, M., Kita, K., Kondo, Y., Li, X., Lou, S. R., Nehr, S., Shao, M., Zeng, L. M., Wahner, A., Zhang, Y. H., and Hofzumahaus, A.: Observation and modelling of OH and HO2 concentrations in the Pearl River Delta 2006: a missing OH source in a VOC rich atmosphere, Atmos. Chem. Phys. Discuss., 11, 11311–11378, http://dx.doi.org/10.5194/acpd-11-11311-2011doi:10.5194/acpd-11-11311-2011, 2011.

%Mao, J., Jacob, D. J., Evans, M. J., Olson, J. R., Ren, X., Brune, W. H., %Clair, J. M. S., Crounse, J. D., Spencer, K. M., Beaver, M. R., Wennberg, P. %O., Cubison, M. J., Jimenez, J. L., Fried, A., Weibring, P., Walega, J. G., %Hall, S. R., Weinheimer, A. J., Cohen, R. C., Chen, G., Crawford, J. H., %McNaughton, C., Clarke, A. D., Jaeglé, L., Fisher, J. A., Yantosca, R. %M., Le Sager, P., and Carouge, C.: Chemistry of hydrogen oxide radicals %(HOx) in the Arctic troposphere in spring, Atmos. Chem. Phys., 10, %5823-5838, 10.5194/acp-10-5823-2010, 2010. Mao, J., Jacob, D. J., Evans, M. J., Olson, J. R., Ren, X., Brune, W. H., Clair, J. M. S., Crounse, J. D., Spencer, K. M., Beaver, M. R., Wennberg, P. O., Cubison, M. J., Jimenez, J. L., Fried, A., Weibring, P., Walega, J. G., Hall, S. R., Weinheimer, A. J., Cohen, R. C., Chen, G., Crawford, J. H., Jaegl�, L., Fisher, J. A., Yantosca, R. M., Le Sager, P., and Carouge, C.: Chemistry of hydrogen oxide radicals (HOx) in the Arctic troposphere in spring, Atmos. Chem. Phys. Discuss., 10, 6955–6994, http://dx.doi.org/10.5194/acpd-10-6955-2010doi:10.5194/acpd-10-6955-2010, 2010.

Molina, M. J. and Molina, L. T.: Megacities and atmospheric pollution, J. Air Waste Manage. Assoc., 54, 644–680, 2004.

Monks, P. S., Granier, C., Fuzzi, S., Stohl, A., Williams, M. L., Akimoto, H., Amann, M., Baklanov, A., Baltensperger, U., Bey, I., Blake, N., Blake, R. S., Carslaw, K., Cooper, O. R., Dentener, F., Fowler, D., Fragkou, E., Frost, G. J., Generoso, S., Ginoux, P., Grewe, V., Guenther, A., Hansson, H. C., Henne, S., Hjorth, J., Hofzumahaus, A., Huntrieser, H., Isaksen, I. S. A., Jenkin, M. E., Kaiser, J., Kanakidou, M., Klimont, Z., Kulmala, M., Laj, P., Lawrence, M. G., Lee, J. D., Liousse, C., Maione, M., McFiggans, G., Metzger, A., Mieville, A., Moussiopoulos, N., Orlando, J. J., O'Dowd, C. D., Palmer, P. I., Parrish, D. D., Petzold, A., Platt, U., Pöschl, U., Prevot, A. S. H., Reeves, C. E., Reimann, S., Rudich, Y., Sellegri, K., Steinbrecher, R., Simpson, D., ten Brink, H., Theloke, J., van der Werf, G. R., Vautard, R., Vestreng, V., Vlachokostas, C., and von Glasow, R.: Atmospheric composition change – global and regional air quality, Atmos. Environ., 43, 5268–5350, http://dx.doi.org/10.1016/j.atmosenv.2009.08.021doi:10.1016/j.atmosenv.2009.08.021, 2009.

NARSTO: An~assessment~of~tropospheric~ozone~pollution~– A North American perspective NARSTO~Management Office (Envair), Pasco, Washington, http://narsto.org/, 2000.

NARSTO: Improving emission inventories for effective Air Quality Management Across North America, NARSTO 05–001, Pasco, Washington, USA, 2005.

NRC (National Research Council): Rethinking the ozone problem in urban and regional air pollution, National Academy Press, Washington, DC, USA, 1991.

Pathak,~R K., Wu,~W S., and Wang,~T.: Summertime PM$_2.5$~ionic species in four major cities of China: nitrate formation in an ammonia-deficient atmosphere, Atmos. Chem. Phys., 9, 1711–1722, http://dx.doi.org/10.5194/acp-9-1711-2009doi:10.5194/acp-9-1711-2009, 2009.

Pinto,~J P.,~Meng,~Q.,~Dibb,~J E.,~Lefer,~B L.,~Rappenglueck,~B.,~Ren,~X.,~Stutz,~J., Zhang,~R.: Intercomparison of nitrous acid (HONO) measurement techniques during SHARP, AGU fall meeting, San Fransisco, USA, 2010

Ren, X. R., Harder, H., Martinez, M., Lesher, R. L., Oliger, A., Simpas, J. B., Brune, W. H., Schwab, J. J., Demerjian, K. L., He, Y., Zhou, X. L., and Gao, H. G.: OH and HO2 chemistry in the urban atmosphere of New York City, Atmos. Environ., 37, 3639–3651, http://dx.doi.org/10.1016/s1352-2310(03)00459-xdoi:10.1016/s1352-2310(03)00459-x, 2003.

Richter, A., Burrows, J. P., Nuss, H., Granier, C., and Niemeier, U.: Increase in tropospheric nitrogen dioxide over China observed from space, Nature, 437, 129–132, http://dx.doi.org/10.1038/nature04092doi:10.1038/nature04092, 2005.

Ryerson, T. B., Williams, E. J., and Fehsenfeld, F. C.: An efficient photolysis system for fast-response NO2 measurements, J. Geophys. Res.-Atmos., 105, 26447–26461, 2000.

Sander, S. P., J. Abbatt, J. R. Barker, J. B. Burkholder, R. R. Friedl, D. M. Golden, R. E. Huie, C. E. Kolb, M. J. Kurylo, G. K. Moortgat, V. L. Orkin and P. H. Wine: Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation No. 17, JPL Publication 10-6, Jet Propulsion Laboratory, Pasadena, http://jpldataeval.jpl.nasa.gov, 2011.

Shao, M., Lu, S. H., Liu, Y., Xie, X., Chang, C. C., Huang, S., and Chen, Z. M.: Volatile organic compounds measured in summer in Beijing and their role in ground-level ozone formation, J. Geophys. Res.-Atmos., 114, D00g06, http://dx.doi.org/10.1029/2008jd010863doi:10.1029/2008jd010863, 2009.

Shirley, T. R., Brune, W. H., Ren, X., Mao, J., Lesher, R., Cardenas, B., Volkamer, R., Molina, L. T., Molina, M. J., Lamb, B., Velasco, E., Jobson, T., and Alexander, M.: Atmospheric oxidation in the Mexico City Metropolitan Area (MCMA) during April 2003, Atmos. Chem. Phys., 6, 2753–2765, http://dx.doi.org/10.5194/acp-6-2753-2006doi:10.5194/acp-6-2753-2006, 2006.

Sillman, S., Logan, J. A., and Wofsy, S. C.: The sensitivity of ozone to nitrogen oxides and hydrocarbons in regional ozone episodes, J. Geophys. Res., 95, 1837–1851, 1990.

Slusher, D. L., Huey, L. G., Tanner, D. J., Flocke, F. M., and Roberts, J. M.: A thermal dissociation-chemical ionization mass spectrometry (TD-CIMS) technique for the simultaneous measurement of peroxyacyl nitrates and dinitrogen pentoxide, J. Geophys. Res.-Atmos., 109, D19315, 10.1029/2004jd004670, 2004.

Streets, D. G.,~Fu, J. S.,~Jang, C. J.,~Hao, J. M.,~He, K. B.,~Tang, X. Y., Zhang Y. H., Wang, Z. F., ~Li, Z. P., ~Zhang, Q.,~Wang, L. T., Wang, B. Y., and~Yu, C.: Air quality during the 2008 Beijing Olympic Games, Atmos. Environ., 41, 480–492, 2008.

Su, H., Cheng, Y. F., Shao, M., Gao, D. F., Yu, Z. Y., Zeng, L. M., Slanina, J., Zhang, Y. H., and Wiedensohler, A.: Nitrous acid (HONO) and its daytime sources at a rural site during the 2004 PRIDE-PRD experiment in China, J. Geophys. Res.-Atmos., 113, D14312, 10.1029/2007jd009060, 2008.

Thornton, J. and Abbatt, J. P. D.: Measurements of HO2 uptake to aqueous aerosol: Mass accommodation coefficients and net reactive loss, J. Geophys. Res.-Atmos., 110, D08309, 10.1029/2004jd005402, 2005.

Thornton, J. A., Jaegle, L., and McNeill, V. F.: Assessing known pathways for HO2 loss in aqueous atmospheric aerosols: Regional and global impacts on tropospheric oxidants, J. Geophys. Res.-Atmos., 113, D05303, 10.1029/2007jd009236, 2008.

van Donkelaar, A., Martin, R. V., Brauer, M., Kahn, R., Levy, R., Verduzco, C., and Villeneuve, P. J.: Global Estimates of Ambient Fine Particulate Matter Concentrations from Satellite-Based Aerosol Optical Depth: Development and Application, Environ. Health Perspect., 118, 847–855, http://dx.doi.org/10.1289/ehp.0901623doi:10.1289/ehp.0901623, 2010.

Volkamer, R., Sheehy, P., Molina, L. T., and Molina, M. J.: Oxidative capacity of the Mexico City atmosphere – Part 1: A radical source perspective, Atmos. Chem. Phys., 10, 6969–6991, http://dx.doi.org/10.5194/acp-10-6969-2010doi:10.5194/acp-10-6969-2010, 2010.

Wang, T., Nie, W., Gao, J., Xue, L. K., Gao, X. M., Wang, X. F., Qiu, J., Poon, C. N., Meinardi, S., Blake, D., Wang, S. L., Ding, A. J., Chai, F. H., Zhang, Q. Z., and Wang, W. X.: Air quality during the 2008 Beijing Olympics: secondary pollutants and regional impact, Atmos. Chem. Phys., 10, 7603–7615, http://dx.doi.org/10.5194/acp-10-7603-2010doi:10.5194/acp-10-7603-2010, 2010.

Wood, E. C., Herndon, S. C., Onasch, T. B., Kroll, J. H., Canagaratna, M. R., Kolb, C. E., Worsnop, D. R., Neuman, J. A., Seila, R., Zavala, M., and Knighton, W. B.: A case study of ozone production, nitrogen oxides, and the radical budget in Mexico City, Atmos. Chem. Phys., 9, 2499–2516, http://dx.doi.org/10.5194/acp-9-2499-2009doi:10.5194/acp-9-2499-2009, 2009.

Yang, Q., Wang, Y. H., Zhao, C., Liu, Z., Gustafson, W. I. J., and Shao, M.: NOx emission reduction and its effects on ozone during the 2008 Olympic Games, Environ. Sci. Technol., 45, 6404–6410, http://dx.doi.org/10.1021/es200675vdoi:10.1021/es200675v, 2011.

Zhang, Q., Streets, D. G., Carmichael, G. R., He, K. B., Huo, H., Kannari, A., Klimont, Z., Park, I. S., Reddy, S., Fu, J. S., Chen, D., Duan, L., Lei, Y., Wang, L. T., and Yao, Z. L.: Asian emissions in 2006 for the NASA INTEX-B mission, Atmos. Chem. Phys., 9, 5131–5153, http://dx.doi.org/10.5194/acp-9-5131-2009doi:10.5194/acp-9-5131-2009, 2009.

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., Fan, S. J., and Liu, S. C.: Regional ozone pollution and observation-based approach for analyzing ozone-precursor relationship during the PRIDE-PRD2004 campaign, Atmos. Environ., 42, 6203–6218, 10.1016/j.atmosenv.2008.05.002, 2008.

Zhao, C., Wang, Y. H., and Zeng, T.: East China Plains: A "Basin" of Ozone Pollution, Environ. Sci. Technol., 43, 1911–1915, 10.1021/es8027764, 2009a.

Zhao, C., Wang, Y., Choi, Y., and Zeng, T.: Summertime impact of convective transport and lightning NOx production over North America: modeling dependence on meteorological simulations, Atmos. Chem. Phys., 9, 4315–4327, http://dx.doi.org/10.5194/acp-9-4315-2009doi:10.5194/acp-9-4315-2009, 2009.

Zhao, C. and Wang, Y. H.: Assimilated inversion of NOx emissions over east Asia using OMI NO2 column measurements, Geophys. Res. Lett., 36, L06805, http://dx.doi.org/10.1029/2008gl037123doi:10.1029/2008gl037123, 2009.

Zhao, C., Wang, Y. H., Yang, Q., Fu, R., Cunnold, D., and Choi, Y.: Impact of East Asian summer monsoon on the air quality over China: View from space, J. Geophys. Res.-Atmos., 115, D09301, http://dx.doi.org/10.1029/2009jd012745doi:10.1029/2009jd012745, 2010.

Zhu, T., Li, X., Hu, M., Tang, X., Team~CareBeijing: Air pollution characteristics before, during and after the Beijing Olympics, Epidemiology, http://dx.doi.org/10.1097/01.ede.0000362836.37333.86doi:10.1097/01.ede.0000362836.37333.86, 2009.