About RCEC
Faculty/Staff
Education/Visiting/Others
Chou, Charles C.-K.周崇光
Research Fellow and Deputy Director
Research Interests
Long-term trends in the East-Asian continental pollution outbreaks and background air quality around Taiwan The East-Asia (EA), in particular the eastern and northern China, is one of the major source regions of air pollutants in the world. The pollutants transported with the EA continental outflows could have significant impacts to the atmospheric composition and air quality in the downwind areas. Taiwan is under the lee side of the winter monsoons originating in the EA continent and, consequently, receives air pollutants transported by the monsoons. Long-term observation of the atmospheric composition at background sites deserves our efforts because it could provide crucial evidences for the changes in our environment.
Production, transformation and transport of ozone and aerosols with implications for air pollution control strategies Fine particulate matter (PM2.5) and ozone (O3) are the major air pollutants in not only Taiwan but also most of the urban areas in the world. Formulation of an effective control strategy for the ambient levels of PM2.5 and O3 is thereby a great challenge. Both O3 and a large fraction of PM2.5 are known as secondary pollutants, which are products of atmospheric chemical reactions among the gaseous precursors emitted from respective pollution sources. An in-depth study upon the physical and chemical processes will improve our scientific knowledge for the formulation of strategies of pollution reduction.
Representative Publications
Chou, C. C.-K.*, Lung, S.-C. C., Hsiao, T.-C., Lee, C.-T. (2022). Regional and Urban Air Quality in East Asia: Taiwan. In: Akimoto, H., Tanimoto, H. (eds) Handbook of Air Quality and Climate Change. Springer, Singapore. https://doi.org/10.1007/978-981-15-2527-8_71-1.
Salvador, C. M., Chou, C. C.-K.*, Ho, T.-T., Ku, I-T., Tsai, C.-Y., Tsao, T.-M., Tsai, M.-J., Su, T.-C. (2022). Extensive urban air pollution footprint evidenced by submicron organic aerosols molecular composition. npj Clim Atmos Sci, 5, 96. https://doi.org/10.1038/s41612-022-00314-x
Jhang S.-R., Chen, Y.-Y., Shiau, Y.-J., Lee, C.-W., Chen, W.-N., Chang, C.-C., Chiang, C.-F., Guo, H.-Y., Wang, P.-K., Chou, C. C.-K.* (2022). Denitrifiers and nitrous oxide emissions from a subtropical vegetable cropland. ACS Earth and Space Chemistry, Article ASAP, https://doi.org/10.1021/acsearthspacechem.2c00106
Jung, C.-C., Chou, C. C.-K.*, Huang, Y.-T., Chang, S.-Y., Lee, C.-T., Lin, C.-Y., Cheung, H.-C., Kuo, W.-C., Chang, C.-W., Chang, S.-C. (2022). Isotopic signatures and source apportionment of Pb in ambient PM2.5. Scientific Reports,12,4343. https://doi.org/10.1038/S41598-022-08096-1
Salvador, C. M., Chou, C. C.-K.*, Cheung, H.-C., Ho, T.-T., Tsai, C.-Y., Tsao, T. -M., Tsai, M.-J., Su, T.-C. (2020). Measurements of submicron organonitrate particles: Implications for the impacts of NOx pollution in a subtropical forest. Atmospheric Research, 245, 105080. https://doi.org/10.1016/j.atmosres.2020.105080
Cheung, H. C., Chou, C. C.-K.*, Lee, C. S. L., Kuo, W.-C., Chang, S.-C. (2020). Hygroscopic properties and cloud condensation nuclei activity of atmospheric aerosols under the influences of Asian continental outflow and new particle formation at a coastal site in eastern Asia. Atmos. Chem. Phys., 20, 5911–5922. https://doi.org/10.5194/acp-20-5911-2020
Droste, E. S., Adcock, K. E., Ashfold, M. J., Chou, C. C.-K., Fleming, Z., Fraser, P. J., Gooch, L. J., Hind, A. J., Langenfelds, R. L., Leedham Elvidge, E., Mohd Hanif, N., O'Doherty, S., Oram, D. E., Ou-Yang, C.-F., Panagi, M., Reeves, C. E., Sturges, W. T., and Laube, J. C. (2020). Trends and emissions of six perfluorocarbons in the northern hemisphere and southern hemisphere. Atmos. Chem. Phys., 20, 4787–4807, https://doi.org/10.5194/acp-20-4787-2020.
Adcock, K. E.*, Ashfold, M. J., Chou, C. C.-K., Gooch, L. J., Hanif, N., Laube, J. C., Oram, D. E., .Ou-Yang, C.-F., Panagi, M., Surges, W. T., Reeves, C. E. (2020). Investigation of East Asian Emissions of CFC-11 Using Atmospheric Observations in Taiwan. Environmental Science & Technology, 54, 3814-3822. https://pubs.acs.org/doi/10.1021/acs.est.9b06433
Lee, C. S. L., Chou, C. C.-K.*, Cheung, H. C., Tsai, C.-Y., Huang, W.-R., Huang, S.-H., Chen, M.-J., Liao, H.-T., Wu, C.-F., Tsao, T.-M., Tsai, M.-J., Su, T.-C. (2019). Seasonal variation of chemical characteristics of fine particulate matter at a high-elevation subtropical forest in East Asia. Environmental Pollution, 246, 668-677. DOI: 10.1016/J.ENVPOL.2018.11.033.
Jung, C.-C., Chou, C. C.-K.*, Lin, C.-Y., Shen, C.-C., Lin, Y.-C., Huang, Y.-T., Tsai, C.-Y., Yao, P.-H., Huang, C.-R., Huang, W.-R., Chen, M.-J., Huang, S.-H., Chang, S.-C. (2019). C-Sr-Pb isotopic characteristics of PM2.5 transported on the East-Asian continental outflows. Atmos. Res., 223, 88-97. DOI: 10.1016/J.ATMOSRES.2019.03.011.
Chou, C. C.-K.*, Hsu, W.-C., Chang, S.-Y., Chen, W.-N., Chen, M.-J., Huang, W.-R., Huang, S.-H., Tsai, C.-Y., Chang, S.-C., Lee, C.-T., Liu, S.-C. (2017). Seasonality of the mass concentration and chemical composition of aerosols around an urbanized basin in East Asia. J. Geophys. Res. Atmos., 122, doi:10.1002/ 2016JD025728
Salvador, C. M., Ho, T.-T., Chou, C. C.-K.*, Chen, M.-J., Huang, W.-R., Huang, S.-H. (2016). Characterization of the organic matter in submicron urban aerosols using a Thermo-Desorption Proton-Transfer-Reaction Time-of-Flight Mass Spectrometer (TD-PTR-TOF-MS). Atmos. Environ., 140, 565-575. DOI: 10.1016/J.ATMOSENV.2016.06.029
Cheung, H. C., Chou, C. C.-K.*, Chen, M.-J., Huang, W.-R., Huang, S.-H., Tsai, C.-Y., Lee, C. S. L. (2016). Seasonal variations of ultra-fine and submicron aerosols in Taipei, Taiwan: implications for particle formation processes in a subtropical urban area. Atmos. Chem. Phys., 16, 1317-1330. DOI: 10.5194/ACP-16-1317-2016
Salvador, C. M. and Chou, C. C.-K.* (2014). Analysis of semi-volatile materials (SVM) in fine particulate matter. Atmos. Environ., 95, 288-295.
Cheung, H. C., Chou, C. C.-K.*, Huang, W.-R., and Tsai, C.-Y. (2013). Characterization of ultrafine particle number concentration and new particle formation in urban environment of Taipei, Taiwan. Atmos. Chem. Phys., 13, 8935-8946. https://doi.org/10.5194/acp-13-8935-2013.
Lin, C.-Y.*, Chou, C. C.-K., Wang, Z., Lung, S.-C., Lee, C.-T., Yuan, C.-S., Chen, W.-N., Chang, S.-Y., Hsu, S.-C., Chen, W.-C., Liu, S. C. (2012). Impact of different transport mechanisms of Asian dust and anthropogenic pollutants to Taiwan. Atmos. Environ., 60, 403-418.
Chou, C. C.-K.*, Tsai, C.-Y., Chang, C.-C., Lin, P.-H., Liu, S. C., Zhu, T. (2011). Photochemical production of ozone in Beijing during the 2008 Olympic Games. Atmos. Chem. Phys., 11, 9825-9837. https://doi.org/10.5194/acp-11-9825-2011.
Chou, C. C.-K.*, Lee, C. T., Cheng, M. T., Yuan, C. S., Chen, S. J., Wu, Y. L., Hsu, W. C., Lung, S. C., Hsu, S. C., Lin, C. Y., Liu, S. C. (2010). Seasonal variations and spatial distribution of carbonaceous aerosols in Taiwan, Atmos. Chem. Phys, 10, 9563–9578. https://doi.org/10.5194/acp-10-9563-2010.
Lu, K., Zhang, Y., Su, H., Brauers, T., Chou, C. C.-K., Hofzumahaus, A., Liu, S. C., Kondo, Y, Shao, M., Wahner, A., Wang, J., Wang, X., Zhu, T.* (2010). Oxidant (O3 + NO2) production processes and formation regimes in Beijing, J. Geophys. Res., 115, D07303, doi:10.1029/2009JD012714.
Chou, C. C.-K.*, Tsai, C.-Y., Shiu, C. J., Liu, S. C., Zhu, T. (2009). 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., 114, D00G01, https://doi.org/10.1029/2008JD010446
Chou, C. C.-K.*, Lee, C.-T., Yuan, C. S., Hsu, W. C., Hsu, S. C., Liu, S. C. (2008). Implications of the chemical transformation of Asian outflow aerosols for the long-range transport of inorganic nitrogen species. Atmospheric Environment, 42, 7508-7519. https://doi.org/10.1016/j.atmosenv.2008.05.049.
Chou, C. C.-K.*, Lee, C.-T., Chen, W.-N., Chang, S.-Y., Chen, T.-K., Lin, C.-Y., Chen, J.-P. (2007). Lidar observations of the diurnal variations in the depth of urban mixing layer: A case study on the air quality deterioration in Taipei, Taiwan. Science of the Total Environment, 374, 156-166.
Chou, C. C.-K.*, Liu, S. C., Lin, C.-Y., Shiu, C.-J., Chang, K.-H. (2006), The trend of surface ozone in Taipei, Taiwan, and its causes: implications for ozone control strategies. Atmospheric Environment, 40, 3898-3908. https://doi.org/10.1016/j.atmosenv.2006.02.018.
Chou, C. C.-K.*, Chen, W. N., Chang, S. Y., Chen, T. K., Huang, S. H. (2005). Specific absorption cross-section and elemental carbon content of urban aerosols. Geophysical Research Letters, 32, L21808, doi:10.1029/2005GL024301.
Chou, C. C.-K.*, Huang, S.-H., Chen, T.-K., Lin, C.-Y., Wang, L.-C. (2005). Size segregated characterization of atmospheric aerosols in Taipei during Asian outflow episodes. Atmospheric Research, 75, 89-109.
Chou, C. C.-K.*, Lin, C.-Y., Chen, T.-K., Hsu, S.-C., Lung, S.-C., Liu, S. C., Young, C.-Y. (2004). Influence of long-range transported dust particles on local air quality: A case study on the Asian dust episodes in Taipei during the spring of 2002. Terrestrial Atmospheric and Oceanic Sciences, 15, 881-899.
Chou, C. C.-K.*, Chen, T.-K., Huang, S.-H., Liu, S. C. (2003). Radiative Absorption Capability of Asian Dust with Black Carbon Contamination. Geophysical Research Letters, 30: 1616-1619, doi:10.1029/2003GL017076.
Highlights
Extensive urban air pollution footprint evidenced by submicron organic aerosols molecular composition. (Salvador et al, npj Clim Atmos Sci, 5, 96, 2022) It is well known that organic aerosol is among the major components of particulate matters (e.g., PM2.5) in the atmosphere, whereas the molecular composition of atmospheric organic aerosols remains mostly unclear. This study successfully resolved >80% of organic aerosol mass into explicit molecular components, which was a major breakthrough in aerosol characterization. Moreover, our results evidenced the significance of the transport and transformation of urban air pollutants driving the changes in the atmospheric composition in downwind rural/remote areas of a megacity. This observed fact has not yet been reproduced successfully in theoretical simulations of atmospheric circulations and, thereby, suggests a significant knowledge gap in the dynamics of atmospheric boundary layer.
Isotopic signatures and source apportionment of Pb in ambient PM2.5. (Jung et al., Scientific Reports, 12, 4343, 2022.) This study is the first one resolving successfully the sources of atmospheric Pb in this region. The results showed that the contribution of coal-fired facilities was overwhelming, whereas fossil-fuel vehicles remained a major source of atmospheric Pb despite the current absence of a leaded gasoline supply, implying the potential co-benefits of renewable energy for mitigation of climate changes and improvement of air quality. Moreover, this is the first isotopic dataset of the Pb associated to PM2.5 for this region, which would contribute to a better attribution of the geographical distribution of the isotopic composition of Pb in the atmosphere.
Denitrifiers and nitrous oxide emissions from a subtropical vegetable cropland. (Jhang et al., ACS Earth and Space Chemistry, 6, 2024-2031, 2022.) This paper presented the first soil-atmosphere N2O flux data set on a farmland scale in Taiwan and, to the best of our knowledge, in subtropical region. Our results revealed that fertilization and soil temperature significantly affected the microbial community throughout the cultivation periods, leading to an increased abundance of denitrifiers. The total N2O–N efflux in this study accounts for 2.3–2.5% of the nitrogen in the fertilizers, which is significantly higher than the IPCC default parameter of 1%. The results underline the significance of N2O emissions from fertilized soils, and discover that the emissions are significantly underestimated in the current national emission inventories of greenhouse gases. This study will contribute to a more representative emission factor of N2O from fertilizers applied in the tropical and subtropical Asia.
