ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-11-21971-2011 Up/Down trend in the MODIS Aerosol Optical Depth and its relationship to the Sulfur Dioxide Emission Changes in China during 2000 and 2010 Itahashi S. 1 Uno I. 2 Yumimoto K. 3 Irie H. 4 Osada K. 5 Ogata K. 6 Fukushima H. 6 Wang Z. 7 Ohara T. 8 Department of Earth System Science and Technology, Kyushu University, Fukuoka, Japan Research Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan Meteorological Research Institute, Tsukuba, Ibaraki, Japan Research Institute for Global Change, JAMSTEC, Yokohama, Japan Graduate School of Environmental Sciences, Nagoya University, Nagoya, Japan School of High-Technology for Human Welfare, Tokai University, Numazu, Japan Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan 04 08 2011 11 8 21971 21993 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys-discuss.net/11/21971/2011/acpd-11-21971-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/11/21971/2011/acpd-11-21971-2011.pdf

Anthropogenic SO<sub>2</sub> emissions increased alongside economic development in China at a rate of 12.7 % yr<sup>−1</sup> from 2000 to 2005. However, under new Chinese government policy, SO<sub>2</sub> emissions declined by 3.9 % yr<sup>−1</sup> between 2005 and 2009. Between 2000 and 2010, we found that the variability in the fine-mode (submicron) aerosol optical depth (AOD) over the oceans adjacent to East Asia increased by 4–8 % yr<sup>−1</sup> to a peak around 2005–2006 and subsequently decreased by 4–7 % yr<sup>−1</sup>, based on observations by the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA's Terra satellite and simulations by a chemical transport model. This trend is consistent with ground-based observations of the number-size distribution of aerosol particles at a mountainous background observation site in central Japan. These fluctuations in SO<sub>2</sub> emission intensity and AOD are thought to reflect the widespread installation of fuel-gas desulfurization (FGD) devices in power plants in China because aerosol sulfate is a major determinant of the AOD in East Asia. Using a chemical transport model, we confirmed that the above-mentioned fluctuation in AOD is mainly caused by changes in SO<sub>2</sub> emission rather than by varying meteorological conditions in East Asia. High correlation was also found between satellite-retrieved SO<sub>2</sub> vertical column density and bottom-up SO<sub>2</sub> emissions, both of which were also consistent with observed AOD trends. We proposed a simplified approach for evaluating changes in SO<sub>2</sub> emissions in China, combining the use of modeled sensitivity coefficients that describe the variation of AOD with changes in SO<sub>2</sub> emissions and satellite retrieval. Satellite measurements of the AOD above Sea of Japan marked the 4.1 % yr<sup>−1</sup> declining between 2007 and 2010, and this correspond to the SO<sub>2</sub> emissions from China decreased by ~9 % yr<sup>−1</sup> between the same period.

 References Byun, D. W. and Schere, K. L.: Review of the governing equations, computational algorithms, and other components of the Model-3 Community Multiscale Air Quality (CMAQ) modeling system, Appl. Mech. Rev., 59, 51–77, 2006. Carmichael G. R., Zhang, Y., Chen, L.-L., Hong, M.-S., and Ueda, H.: Seasonal variation of aerosol composition at Cheju island, Korea, Atmos. Environ., 30, 2407–2416, 1996. Chu, D. A., Kaufman, Y. J., Ichoku, C., Remer, L. A., Tanre, D., and Holben, B. N.: Validation of MODIS aerosol optical depth retrieval over land, Geophys. Res. Lett., 29(12), 1617, http://dx.doi.org/10.1029/2001GL013205doi:10.1029/2001GL013205, 2002. Gottwald, M. and Bovensmann, H. (Eds.): SCIAMACHY: Exploring the Changing Earth's Atmosphere, 1st edition, Springer, ISBN~978-9-481-9895-5, 2011. Haywood, J. and Boucher, O.: Estimates of the direct and indirect radiative forcing due to tropospheric aerosols: a review, Rev. Geophys., 38, 513–543, 2000. Hofmann, D., Barnes., J., O'Neill, M., Trudeau, M., and Neely, R.: Increase in background stratospheric aerosols observed with lidar at Mauna Loa Observatory and Boulder, Colorado, Geophys. Res. Lett., 36, L15808, http://dx.doi.org/10.1029/2009GL039008doi:10.1029/2009GL039008, 2009. Huebert, B. J., Bates, T., Russell, P. B., Shi, G., Kim, Y. J., Kawamura, K., Carmichael, G., and Nakajima, T.: An overview of ACE-Asia: Strategies for quantifying the relationships between Asian aerosols and their climatic impacts, J. Geophys. Res., 108, 8633, http://dx.doi.org/10.1029/2003JD003550doi:10.1029/2003JD003550, 2003. Itahashi, S., Yumimoto, K., Uno, I., Eguchi, K., Takemura, T., Hara, Y., Shimizu, A., Sugimoto, N., and Liu, Z.: Structure of dust and air pollutant outflow over East Asia in the spring. Geophys. Res. Lett., 37, L20806, http://dx.doi.org/10.1029/2010GL044776doi:10.1029/2010GL044776, 2010. Kaufman, Y. J., Boucher, O., Tanre, D., Chin, M., Remer, L. A., and Takemura, T.: Aerosol anthropogenic component estimated from satellite data, Geophys. Res. Lett., 32, L17804, http://dx.doi.org/10.1029/2005GL023125doi:10.1029/2005GL023125, 2005. Lamsal, L. N., Martin, R. V., Padmanabhan, A., van Donkelaar, A., Zhang, Q., Sioris, C. E., Chance, K., Kurosu, T. P., and Newchurch, M. J.: Application of satellite observations for timely updates to global anthropogenic NO<sub>x</sub> emission inventories, Geophys. Res. Lett., 38, L05810, http://dx.doi.org/10.1029/2010GL046476doi:10.1029/2010GL046476, 2011. Lee, C., Martin, R. V., van Donkelaar, A., O'Byrne, G., Krotkov, N., Richter, A., Huey, L. G., and Holloway, J. S.: Retrieval of vertical columns of sulfur dioxide from SCIAMACHY and OMI: air mass factor algorithm development, validation, and error analysis, J. Geophys. Res., 114, D22303, http://dx.doi.org/10.1029/2009JD012123doi:10.1029/2009JD012123, 2009. Li, C., Zhang, Q., Krotkov, N. A., Streets, D. G., He, K., Tsay, S., and Gleason, J. F.: Recent large reduction in sulfur dioxide emissions from Chinese power plants observed by the Ozone Monitoring Instrument, Geophys. Res. Lett., 37, L08807, http://dx.doi.org/10.1029/2010GL042594doi:10.1029/2010GL042594, 2010. Lu, Z., Streets, D. G., Zhang, Q., Wang, S., Carmichael, G. R., Cheng, Y. F., Wei, C., Chin, M., Diehl, T., and Tan, Q.: Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000, Atmos. Chem. Phys., 10, 6311–6331, http://dx.doi.org/10.5194/acp-10-6311-2010doi:10.5194/acp-10-6311-2010, 2010. Malm, W. C., Sisler, J. F., Huffman, D., Eldred, R. A., and Cahill, T. A.: Spatial and seasonal trends in particle concentration and optical extinction in the United States, J. Geophys. Res., 99, 1347–1370, 1994. Matsumoto, K., Uyama, Y., Hayano, T., Tanimoto, H., Uno, I., and Uematsu, M.: Chemical properties and outflow patterns of anthropogenic and dust particles on Rishiri Island during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia), J. Geophys. Res., 108(D23), 8666, http://dx.doi.org/10.1029/2003JD003426doi:10.1029/2003JD003426, 2003. Ministry of Environmental Protection in China (MEP): Report on the state of the environment in China 2008, Beijing, 2009. Ohara, T., Akimoto, H., Kurokawa, J., Horii, N., Yamaji, K., Yan, X., and Hayasaka, T.: Asian emission inventory for anthropogenic emission sources during the period 1980–2020, Atmos. Chem. Phys., 7, 4419–4444, http://dx.doi.org/10.5194/acp-7-4419-2007doi:10.5194/acp-7-4419-2007, 2007. Osada, K., Kido, M., Nishita, C., Matsunaga, K., Iwasaka, Y., Nagatani, M., and Nakada, H.: Temporal variation of water-soluble ions of free tropospheric aerosol particles over central Japan, Tellus, 59, 742–754, 2007. Osada, K., Ohara, T., Uno, I., Kido, M., and Iida, H.: Impact of Chinese anthropogenic emissions on submicrometer aerosol concentration at Mt.\ Tateyama, Japan, Atmos. Chem. Phys., 9, 9111–9120, http://dx.doi.org/10.5194/acp-9-9111-2009doi:10.5194/acp-9-9111-2009, 2009. Park, R. S., Song, C. H., Han, K. M., Park, M. E., Lee, S. S., and Kim, S. B.: A study on the aerosol optical properties over East Asia using a combination of CMAQ-simulated aerosol optical properties and remote-sensing data via a data assimilation technique, Atmos. Chem. Phys. Discuss., submitted, 2011. Remer, L. A., Tanre, D., Kaufman, Y. J., Ichoku, C., Mattoo, S., Levy, R. C., Chu, D. A., Holben, B., Dubovik, O., Smirnov, A., Martins, J. V., Li, R.-R., and Ahmad, Z.: Validation of MODIS aerosol retrieval over ocean, Geophys. Res. Lett., 29(12), 1618, http://dx.doi.org/10.1029/2001GL013204doi:10.1029/2001GL013204, 2002. Remer, L. A., Kleidman, R. G., Levy, R. C., Kaufman, Y. J., Tanre, D., Mattoo, S., Martins, J. V., Ichoku, C., Koren, I., Yu, H., and Holben, B. N.: Global aerosol climatology from the MODIS satellite sensors, J. Geophys. Res., 113, L14S07, http://dx.doi.org/10.1029/2007JD009661doi:10.1029/2007JD009661, 2008. Ruckstuhl, C., Philipona, R., Behrens, K., Coen, M. C., Dürr, B., Heimo, A., Mätzler, C., Nyeki, S., Ohmura, A., Vuilleumier, L., Weller, M., Wehrli, C., and Zelenka, A.: Aerosol and cloud effects on solar brightening and the recent rapid warming, Geophys. Res. Lett., 35, L12708, http://dx.doi.org/10.1029/2008GL034228doi:10.1029/2008GL034228, 2008. Song, C. H., Park, M. E., Lee, K.H., Ahn, H. J., Lee, Y., kim, J. Y., Han, K. M., Kim, J., Ghim, Y. S., and Kim, Y. J.: An investigation into seasonal and regional aerosol characteristics in East Asia using model-predicted and remotely-sensed aerosol properties, Atmos. Chem. Phys., 8, 6627–6654, http://dx.doi.org/10.5194/acp-8-6627-2008doi:10.5194/acp-8-6627-2008, 2008. Streets, D. G., Wu, Y. and Chin, M.: Two-decadal aerosol trends as a likely explanation of the global dimming/brightening transition, Geophys. Res. Lett., 33, L15806, http://dx.doi.org/10.1029/2006GL026471doi:10.1029/2006GL026471, 2006. Streets, D. G., Yan, F., Chin, M., Diehl, T., Mahowald, N., Schultz, M., Wild, M., Wu, Y., and Yu, C.: Anthropogenic and natural contributions to regional trends in aerosol optical depth, 1986–2006, J. Geophys. Res., 114, D00D18, http://dx.doi.org/10.1029/2008JD011624doi:10.1029/2008JD011624, 2009. Uno, I., Uematsu, M., Hara, Y., He, Y. J., Ohara, T., Mori, A., Kamaya, T., Murano, K., Sadanaga, Y., and Bandow, H.: Systematic analysis of interannual and seasonal variations of model-simulated tropospheric NO<sub>2</sub> in Asia and comparison with GOME-satellite data, Atmos. Chem. Phys., 7, 1671–1681, http://dx.doi.org/10.5194/acp-7-1671-2007doi:10.5194/acp-7-1671-2007, 2007. Wang, K, R., Dickinson, R. E. and Liang, S.: Clear sky visibility has decreased over land globally from 1973 to 2007, Science, 323, 1468–1470, 2009.