References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-11-3281-2011

Analysis on the impact of aerosol optical depth on surface solar radiation in the Shanghai megacity, China

¹ Li

² ³ Shi

¹ He

⁴ Pan

Shanghai Center for Urban Environmental Meteorology, Shanghai Meteorological Bureau, Shanghai, China

Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China

Laboratory for Climate and Ocean-Atmosphere Studies, Peking University, Beijing, China

Shanghai Center for Satellite Remote-sensing and Application, Shanghai Meteorological Bureau, Shanghai, China

06 04 2011

11 7 3281 3289

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This study investigated the decadal variation of the direct surface solar radiation (DiSR) and the diffuse surface solar radiation (DfSR) during 1961–2008 in the Shanghai megacity as well as their relationships to Aerosol Optical Depth (AOD) under clear-sky conditions. Three successive periods with unique features of long term variation of DiSR were identified for both clear-sky and all-sky conditions: a "dimming" period from the late 1960s to the mid 1980s, a "stabilization"/"slight brightening" period from the mid 1980s to the mid 1990s, and a "renewed dimming" period thereafter. During the two dimming periods of DiSR, DfSR brightened significantly under clear-sky conditions, indicating that change in atmospheric transparency resulting from aerosol emission has an important role on decadal variation of surface solar radiation (SSR) over this area. The analysis on the relationship between the Moderate-resolution Imaging Spectroradiometer (MODIS) retrieved AOD and the corresponding hourly measurements of DiSR and DfSR under clear-sky conditions clearly revealed that AOD is significantly correlated and anti-correlated with DfSR and DiSR, respectively, both above 99% confidence in all seasons, indicating the great impact of aerosols on SSR through absorption and/or scattering in the atmosphere. In addition, both AOD and the corresponding DiSR and DfSR measured during the satellite passage over Shanghai show obvious weekly cycles. On weekends, AOD is lower than the weekly average, corresponding to higher DiSR and lower DfSR, while the opposite pattern was true for weekdays. Less AOD on weekends due to the reduction of transportation and industrial activities results in enhancement of atmospheric transparency under cloud free conditions so as to increase DiSR and decrease DfSR simultaneously. Results show that aerosol loading from the anthropogenic emissions is an important modulator for the long term variation of SSR in Shanghai.

References 1

Bäumer, D., Rinke, R., and Vogel, B.: Weekly periodicities of Aerosol Optical Thickness over Central Europe - evidence of an anthropogenic direct aerosol effect, Atmos. Chem. Phys., 8, 83–90, http://dx.doi.org/10.5194/acp-8-83-2008doi:10.5194/acp-8-83-2008, 2008.

Che, H. Z., Shi, G. Y., Zhang, X. Y., Arimoto, R., Zhao, J. Q., Xu, L., Wang, B., and Chen, Z. H.: Analysis of 40~years of solar radiation data from China, 1961–2000, Geophys. Res. Lett., 32, L06803, http://dx.doi.org/10.1029/2004GL022322doi:10.1029/2004GL022322, 2005.

Chu, D. A., Kaufman, Y. J., Ichoku, C., Remer, L. A., Tanré, D., and Holben, B. N.: Validation of MODIS aerosol optical depth retrieval over land, Geophys. Res. Lett., 29(12), 8007, http://dx.doi.org/10.1029/2001GL013205doi:10.1029/2001GL013205, 2002.

Geng, F., Tie, X., Xu, J., Zhou, G., Peng, L., Gao, W., Tang, X., and Zhao, C.: Characterizations of ozone, NO<sub>x</sub>, and VOCs measured in Shanghai, China, Atmos. Environ., 42, 6873–6883, http://dx.doi.org/10.1016/j.atmosenv.2008.05.045doi:10.1016/j.atmosenv.2008.05.045, 2008.

Jin, M., Shepherd, J. M., and King, M. D.: Urban aerosols and their variations with clouds and rainfall: A case study for New York and Houston, J. Geophys. Res., 110, D10S20, http://dx.doi.org/10.1029/2004JD005081doi:10.1029/2004JD005081, 2005.

Kaufman, Y. J., Tanré, D., Remer, L. A., Vermote, E. F., Chu, A., and Holben, B. N.: Operational remote sensing of tropospheric aerosol over land from EOS moderate resolution imaging spectroradiometer, J. Geophys. Res., 102(D14), 17051–17067, http://dx.doi.org/10.1029/96JD03988doi:10.1029/96JD03988, 1997.

Levy, R. C., Remer, L. A., and Dubovik, O.: Global aerosol optical properties and application to Moderate Resolution Imaging Spectroradiometer aerosol retrieval over land, J. Geophys. Res., 112, D13210, http://dx.doi.org/10.1029/2006JD007815doi:10.1029/2006JD007815, 2007.

Li, C. C., Mao, J. T., Alexis, L., Chen, J. C., Yuan, Z. B., Liu, X. Y., Zhu, A. H., and Liu, G. Q.: Characteristics of distribution and seasonal variation of aerosol optical depth in Eastern China with MODIS products, Chinese Sci. Bull., 48, 2094–2100, 2003.

Li, J. P., Wu, Z. W., Jiang, Z. H., and He, J. H.: Can global warming strengthen the East Asian summer monsoon?, J. Climate, 23, 6696–6705, http://dx.doi.org/10.1175/2010JCLI3434.1doi:10.1175/2010JCLI3434.1, 2010.

Liang, F. and Xia, X. A.: Long-term trends in solar radiation and the associated climatic factors over China for 1961–2000, Ann. Geophys., 23, 2425–2432, http://dx.doi.org/10.5194/angeo-23-2425-2005doi:10.5194/angeo-23-2425-2005, 2005.

Mi, W., Li, Z., Xia, X., Holben, B., Levy, R., Zhao, F., Chen, H., and Cribb, M.: Evaluation of the moderate resolution mmaging spectroradiometer aerosol products at two Aerosol Robotic Network stations in China, J. Geophys. Res., 112, D22S08, http://dx.doi.org/10.1029/2007JD008474doi:10.1029/2007JD008474, 2007.

Norris, J. R. and Wild, M.: Trends in aerosol radiative effects over China and Japan inferred from observed cloud cover, solar "dimming," and solar "brightening", J. Geophys. Res., 114, D00D15, http://dx.doi.org/10.1029/2008JD011378doi:10.1029/2008JD011378, 2009.

Pan, L., Che, H., Geng, F., Xia, X., Wang, Y., Zhu, C., Chen, M., Gao, W., and Guo, L.: Aerosol optical properties based on ground measurements over the Chinese Yangtze Delta Region, Atmos. Environ., 44, 2587–2596, http://dx.doi.org/10.1016/j.atmosenv.2010.04.013doi:10.1016/j.atmosenv.2010.04.013, 2010.

Peterson, J. T., Flowers, E. C., Berri, G. J., Reynolds, C. L., and Rudisill, J. H.: Atmospheric turbidity over central North Carolina, J. Appl. Met., 20, 229–241, 1981.

Qian, Y., Kaiser, D. P., Leung, L. R., and Xu, M.: More frequent cloud-free sky and less surface solar radiation in China from 1955 to 2000, Geophys. Res. Lett., 33, L01812, http://dx.doi.org/10.1029/2005GL024586doi:10.1029/2005GL024586, 2006.

Qian, Y., Wang, W., Leung, L. R., and Kaiser, D. P.: Variability of solar radiation under cloud-free skies in China: The role of aerosols, Geophys. Res. Lett., 34, L12804, http://dx.doi.org/10.1029/2006GL028800doi:10.1029/2006GL028800, 2007.

Quaas, J., Boucher, O., Jones, A., Weedon, G. P., Kieser, J., and Joos, H.: Exploiting the weekly cycle as observed over Europe to analyse aerosol indirect effects in two climate models, Atmos. Chem. Phys., 9, 8493–8501, http://dx.doi.org/10.5194/acp-9-8493-2009doi:10.5194/acp-9-8493-2009, 2009.

Remer, L. A., Kaufman, Y. J., Tanré, D., Mattoo, S., Chu, D. A., Martins, J. V., Li, R. R., Ichoku, C., Levy, R. C., Kleidman, R. G., Eck, T. F., Vermote, E., and Holben, B. N.: The MODIS aerosol algorithm, products, and validation, J. Atmos. Sci., 62(4), 947–973, http://dx.doi.org/10.1175/JAS3385.1doi:10.1175/JAS3385.1, 2005.

Shi, G. Y., Hayasaka, T., Ohmura, A., Chen, Z. H., Wang, B., Zhao, J. Q., Che, H. Z., and Xu, L.: Data quality assessment and the long-term trend of ground solar radiation in China, J. Appl. Meteor. Climatol., 47, 1006–1016, http://dx.doi.org/10.1175/2007JAMC1493.1doi:10.1175/2007JAMC1493.1, 2008.

Smirnov, A., Holben, B. N., Eck, T. F., Slutsker, I., Chatenet, B., and Pinker, R. T.: Diurnal variability of aerosol optical depth observed at AERONET (Aerosol Robotic Network) sites, Geophys. Res. Lett., 29(23), 2115, http://dx.doi.org/10.1029/2002GL016305doi:10.1029/2002GL016305, 2002.

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.: Discerning human and natural signatures in regional aerosol trends, 1980–2006, J. Geophys. Res., 114, D00D18, http://dx.doi.org/10.1029/2008JD011624doi:10.1029/2008JD011624, 2009.

Wild, M.: Global dimming and brightening: A review, J. Geophys. Res., 114, D00D16, http://dx.doi.org/10.1029/2008JD011470doi:10.1029/2008JD011470, 2009.

Wild, M., Gilgen, H., Roesch, A., Ohmura, A., Long, C. N., Dutton, E. G., Forgan, B., Kallis, A., Russak, V., and Tsvetkov, A.: From dimming to brightening: decadal changes in solar radiation at Earth's surface, Science, 308, 847–850, http://dx.doi.org/10.1126/science.1103215doi:10.1126/science.1103215, 2005.

Wu, Z. W., Wang, B., Li, J. P., and Jin, F. F.: An empirical seasonal prediction model of the East Asian summer monsoon using ENSO and NAO, J. Geophys. Res., 114, D18120, http://dx.doi.org/10.1029/2009JD011733doi:10.1029/2009JD011733, 2009.

Xia, X.: A closer looking at dimming and brightening in China during 1961–2005, Ann. Geophys., 28, 5, 1121–1132, http://dx.doi.org/10.5149/angeo-28-1121-2010doi:10.5149/angeo-28-1121-2010, 2010.

Xia, X., Eck T. F., Holben, B. N., Phillippe, G., and Chen, H. B.: Analysis of the weekly cycle of aerosol optical depth using AERONET and MODIS data, J. Geophys. Res., 113, D14217, http://dx.doi.org/10.1029/2007JD009604doi:10.1029/2007JD009604, 2008.

Xu, J., Geng, F., Gao, W., and Zhen, C.: Aerosol scattering coefficient and the factors affecting them in Shanghai Pudong, Acta Sci. Circumstantiae, 30, 211-216, 2009.

Yang, J. M., Qiu, J. H., and Zhao, Y. L.: Validation of Aerosol Optical Depth from Terra and Aqua MODIS retrievals over a tropical coastal site in China, Atmos. Ocean. Sci. Lett., 3, 36–39, 2010.