ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-12-9581-2012 Atmospheric impacts on climatic variability of surface incident solar radiation Wang K. C. 1 Dickinson R. E. 2 Wild M. 3 Liang S. 4 State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, Beijing, China Department of Geological Sciences, The University of Texas at Austin, Austin, TX 78712, USA Institute for Atmospheric and Climate Science, ETH Zürich, 8092 Zürich, Switzerland Department of Geography, University of Maryland, College Park, MD 20742, USA 22 10 2012 12 20 9581 9592 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.net/12/9581/2012/acp-12-9581-2012.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/9581/2012/acp-12-9581-2012.pdf

The Earth's climate is driven by surface incident solar radiation (<i>R</i><sub>s</sub>). Direct measurements have shown that <i>R</i><sub>s</sub> has undergone significant decadal variations. However, a large fraction of the global land surface is not covered by these observations. Satellite-derived <i>R</i><sub>s</sub> has a good global coverage but is of low accuracy in its depiction of decadal variability. This paper shows that daily to decadal variations of <i>R</i><sub>s</sub>, from both aerosols and cloud properties, can be accurately estimated using globally available measurements of Sunshine Duration (SunDu). In particular, SunDu shows that since the late 1980's <i>R</i><sub>s</sub> has brightened over Europe due to decreases in aerosols but dimmed over China due to their increases. We found that variation of cloud cover determines <i>R</i><sub>s</sub> at a monthly scale but that aerosols determine the variability of <i>R</i><sub>s</sub> at a decadal time scale, in particular, over Europe and China. Because of its global availability and long-term history, SunDu can provide an accurate and continuous proxy record of <i>R</i><sub>s</sub>, filling in values for the blank areas that are not covered by direct measurements. Compared to its direct measurement, <i>R</i><sub>s</sub> from SunDu appears to be less sensitive to instrument replacement and calibration, and shows that the widely reported sharp increase in <i>R</i><sub>s</sub> during the early 1990s in China was a result of instrument replacement. By merging direct measurements collected by Global Energy Budget Archive with those derived from SunDu, we obtained a good coverage of <i>R</i><sub>s</sub> over the Northern Hemisphere. From this data, the average increase of <i>R</i><sub>s</sub> from 1982 to 2008 is estimated to be 0.87 W m<sup>−2</sup> per decade.

 References Angstrom, A.: Solar and terrestrial radiation. Report to the international commission for solar research on actinometric investigations of solar and atmospheric radiation, Q. J. Roy. Meteorol. Soc., 50, 121–126, 1924. Akinoglu, B. G.: Recent Advances in the Relations between Bright Sunshine Hours and Solar Irradiation, in: Modeling Solar Radiation at the Earth's Surface, edited by: Badescu, V., Springer Berlin Heidelberg, 115–143, 2008. CMA: Observation method of Meteorological radiation, Meteorological Press, Beijing, 1996. Cong, Z. T., Yang, D. W., and Ni, G. H.: Does evaporation paradox exist in China?, Hydrol. Earth Syst. Sci., 13, 357–366, http://dx.doi.org/10.5194/hess-13-357-2009doi:10.5194/hess-13-357-2009, 2009. Dai, A., Karl, T. R., Sun, B., and Trenberth, K. E.: Recent trends in cloudiness over the United States – A tale of monitoring inadequacies, B. Am. Meteorol. Soc., 87, 597–606, 2006. Essa, K. S. and Etman, S. M.: On the relation between cloud cover amount and sunshine duration, Meteor. Atmos. Phys., 87, 235–240, 2004. Evan, A. T., Heidinger, A. K., and Vimont, D. J.: Arguments against a physical long-term trend in global ISCCP cloud amounts, Geophys. Res. Lett., 34, L04701, http://dx.doi.org/10.1029/2006GL028083doi:10.1029/2006GL028083, 2007. Gilgen, H., Wild, M., and Ohmura, A.: Means and trends of shortwave irradiance at the surface estimated from global energy balance archive data, J. Climate, 11, 2042–2061, 1998. Hayasaka, T., Kawamoto, K., Shi, G. Y., and Ohmura, A.: Importance of aerosols in satellite-derived estimates of surface shortwave irradiance over China, Geophys. Res. Lett., 33, L06802, http://dx.doi.org/10.1029/2005GL025093doi:10.1029/2005GL025093, 2006. Hess, M., Koepke, P., and Schult, I.: Optical properties of aerosols and clouds: The software package OPAC, B. Am. Meteorol. Soc., 79, 831–844, 1998. Holben, B. N., Eck, T. F., Slutsker, I., Tanré, D., Buis, J. P., Setzer, A., Vermote, E., Reagan, J. A., Kaufman, Y. J., Nakajima, T., Lavenu, F., Jankowiak, I., and Smirnov, A.: AERONET – a federated instrument network and data archive for aerosol characterization, Remote Sens. Environ., 66, 1–16, 1998. Horseman, A., MacKenzie, A. R., and Timmis, R.: Using bright sunshine at low-elevation angles to compile an historical record of the effect of aerosol on incoming solar radiation, Atmos. Environ., 42, 7600–7610, 2008. Hoyt, D. V.: Percent of Possible Sunshine and the Total Cloud Cover, Mon. Weather Rev., 105, 648–652, 1977. Kaiser, D. P. and Qian, Y.: Decreasing trends in sunshine duration over China for 1954-1998: Indication of increased haze pollution?, Geophys. Res. Lett., 29, 2042, http://dx.doi.org/10.1029/2002GL016057doi:10.1029/2002GL016057, 2002. Kimball, H. H.: Variations in the total and luminous solar radiation with geographical position in the United States, Mon. Weather Rev., 47, 769–793, http://dx.doi.org/10.1175/1520-0493(1919)47<769:vittal>2.0.co;2doi:10.1175/1520-0493(1919)47<769:vittal>2.0.co;2, 1919. 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. Liepert, B. G.: Observed reductions of surface solar radiation at sites in the United States and worldwide from 1961 to 1990, Geophys. Res. Lett., 29, 1421, http://dx.doi.org/10.1029/2002GL014910doi:10.1029/2002GL014910, 2002. Long, C. N., Dutton, E. G., Augustine, J. A., Wiscombe, W., Wild, M., McFarlane, S. A. and Flynn, C. J.: Significant decadal brightening of downwelling shortwave in the continental United States, J. Geophys. Res., 114, D00D06, http://dx.doi.org/10.1029/2008JD011263doi:10.1029/2008JD011263, 2009. Norris, J. R. and Wild, M.: Trends in aerosol radiative effects over Europe inferred from observed cloud cover, solar "dimming" and solar "brightening", J. Geophys. Res., 112, D08214, http://dx.doi.org/10.1029/2006JD007794doi:10.1029/2006JD007794, 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. Ohmura, A.: Observed decadal variations in surface solar radiation and their causes, J. Geophys. Res., 114, D00D05, http://dx.doi.org/10.1029/2008JD011290doi:10.1029/2008JD011290, 2009. Pinker, R. T., Zhang, B., and Dutton, E. G.: Do satellites detect trends in surface solar radiation?, Science, 308, 850–854, 2005. Podgorny, I. A., Li, F., and Ramanathan, V.: Large Aerosol Radiative Forcing due to the 1997 Indonesian Forest Fire, Geophys. Res. Lett., 30, 1028, http://dx.doi.org/10.1029/2002GL015979doi:10.1029/2002GL015979, 2003. Prescott, J. A.: Evaporation from water surface in relation to solar radiation, T. Roy. Soc. South Aust., 64, 114–118, 1940. 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. Raschke, E., Bakan, S., and Kinne, S.: An assessment of radiation budget data provided by the ISCCP and GEWEX-SRB, Geophys. Res. Lett., 33, L07812, http://dx.doi.org/10.1029/2005GL025503doi:10.1029/2005GL025503, 2006. Roderick, M. L. and Farquhar, G. D.: The cause of decreased pan evaporation over the past 50 years, Science, 298, 1410–1411, 2002. Ruckstuhl, C., Norris, J. R., and Philipona, R.: Is there evidence for an aerosol indirect effect during the recent aerosol optical depth decline in Europe?, J. Geophys. Res., 115, D04204, http://dx.doi.org/10.1029/2009JD012867doi:10.1029/2009JD012867, 2010. Sanchez-Lorenzo, A. and Wild, M.: Decadal variations in estimated surface solar radiation over Switzerland since the late 19th century, Atmos. Chem. Phys., 12, 8635–8644, http://dx.doi.org/10.5194/acp-12-8635-2012doi:10.5194/acp-12-8635-2012, 2012. Sanchez-Lorenzo, A., Calbo, J., and Martin-Vide, J.: Spatial and Temporal Trends in Sunshine Duration over Western Europe (1938–2004), J. Climate, 21, 6089–6098, 2008. Sanchez-Lorenzo, A., Calb, J., Brunetti, M. and Deser, C.: Dimming/brightening over the Iberian Peninsula: Trends in sunshine duration and cloud cover and their relations with atmospheric circulation, J. Geophys. Res., 114, D00D09, http://dx.doi.org/10.1029/2008JD011394doi:10.1029/2008JD011394, 2009. 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. Meteorol. Clim., 47, 1006–1016, 2008. Simmons, A. J., Willett, K. M., Jones, P. D., Thorne, P. W., and Dee, D. P.: Low-frequency variations in surface atmospheric humidity, temperature, and precipitation: Inferences from reanalyses and monthly gridded observational data sets, J. Geophys. Res., 115, D01110, http://dx.doi.org/10.1029/2009jd012442doi:10.1029/2009jd012442, 2010. Smith, A., Lott, N., and Vose, R.: The Integrated Surface Database Recent Developments and Partnerships, B. Am. Meteorol. Soc., 92, 704–708, 2011. Stanhill, G. and Cohen, S.: Global dimming: a review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences, Agr. Forest Meteorol., 107, 255–278, 2001. Stanhill, G. and Cohen, S.: Solar radiation changes in the United States during the Twentieth Century: Evidence from sunshine measurements, J. Climate, 18, 1503–1512, 2005. Stevermer, A. J., Petropavlovskikh, I. V., Rosen, J. M., and DeLuisi, J. J.: Development of a global stratospheric aerosol climatology: Optical properties and applications for UV, J. Geophys. Res., 105, 22763–22776, 2000. Tang, W.-J., Yang, K., He, J., and Qin, J.: Quality control and estimation of global solar radiation in China, Sol. Energy, 84, 466–475, 2010. Tang, W.-J., Yang, K., Qin, J., Cheng, C. C. K., and He, J.: Solar radiation trend across China in recent decades: a revisit with quality-controlled data, Atmos. Chem. Phys., 11, 393–406, http://dx.doi.org/10.5194/acp-11-393-2011doi:10.5194/acp-11-393-2011, 2011. van der Werf, G. R., Dempewolf, J., Trigg, S. N., Randerson, J. T., Kasibhatla, P. S., Gigliof, L., Murdiyarso, D., Peters, W., Morton, D. C., Collatz, G. J., Dolman, A. J., and DeFries, R. S.: Climate regulation of fire emissions and deforestation in equatorial Asia, P. Natl. Acad. Sci. USA, 105, 20350–20355, 2008. Wang, K., Dickinson, R. E., and Liang, S.: Clear sky visibility has decreased over land globally from 1973 to 2007, Science, 323, 1468–1470, 2009. Warren, S. G., Eastman, R. M., and Hahn, C. J.: A survey of changes in cloud cover and cloud types over land from surface observations, 1971–96, J. Climate, 20, 717–738, 2007. Wielicki, B. A., Wong, T. M., Allan, R. P., Slingo, A., Kiehl, J. T., Soden, B. J., Gordon, C. T., Miller, A. J., Yang, S. K., Randall, D. A., Robertson, F., Susskind, J., and Jacobowitz, H.: Evidence for large decadal variability in the tropical mean radiative energy budget, Science, 295, 841–844, 2002. 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, 2005. Wild, M., Trüssel, B., Ohmura, A., Long, C.N., König-Langlo, G., Dutton, E. G., and Tsvetkov, A.: Global dimming and brightening: An update beyond 2000, J. Geophys. Res., 114, D00D13, http://dx.doi.org/10.1029/2008JD011382doi:10.1029/2008JD011382, 2009. WMO: Measurement of sunshine duration, WMO guide to meteorological instruments and methods of observation manual on the global observing system, WMO, http://www.wmo.int/pages/prog/gcos/documents/gruanmanuals/CIMO/CIMO_Guide-7th_Edition-2008.pdf (last access: October 2012), 2008. Xia, X.: A closer looking at dimming and brightening in China during 1961–2005, Ann. Geophys., 28, 1121–1132, http://dx.doi.org/10.5194/angeo-28-1121-2010doi:10.5194/angeo-28-1121-2010, 2010. Xia, X.: Significant decreasing cloud cover during 1954–2005 due to more clear-sky days and less overcast days in China and its relation to aerosol, Ann. Geophys., 30, 573–582, http://dx.doi.org/10.5194/angeo-30-573-2012doi:10.5194/angeo-30-573-2012, 2012. Xia, X. A., Wang, P. C., Chen, H. B., and Liang, F.: Analysis of downwelling surface solar radiation in China from National Centers for Environmental Prediction reanalysis, satellite estimates, and surface observations, J. Geophys. Res., 111, D09103, http://dx.doi.org/10.1029/2005JD006405doi:10.1029/2005JD006405, 2006. Yang, K., Koike, T., and Ye, B. S.: Improving estimation of hourly, daily, and monthly solar radiation by importing global data sets, Agr. Forest Meteorol., 137, 43–55, 2006.