Fu C.,Hainan Meteorological Observatory |
Fu C.,CAS Institute of Atmospheric Physics |
Fu C.,Key Laboratory of South China Sea Meteorological Disaster Prevention |
Dan L.,CAS Institute of Atmospheric Physics |
And 4 more authors.
Journal of Environmental Sciences (China) | Year: 2015
The long-term observational data of sunshine duration (SD) and diffuse radiation percentage (defined as diffuse solar radiation/total solar radiation, DRP) on sunny days during 1960-2005 were analyzed in 7 urban agglomerations and the whole of China. The results show that the sunny sunshine duration (SSD) has decreased significantly except at a few stations over northwestern China in the past 46years. An obvious decrease of the SSD is found in eastern China, with the trend coefficients lower than -0.8. Accompanied by the SSD decline, the sunny diffuse radiation percentage (SDRP) in most stations shows obvious increasing trends during the 46years. The averaged SDRP over China has increased 2.33% per decade, while the averaged SSD shows a decrease of -0.13hr/day per decade. The correlation coefficient between SDRP and SSD is -0.88. SSD decreased over urban agglomerations (small to large city clusters) in the past 46years, especially in large cities and medium cities, due to the strong anthropogenic activities and air pollution represented by aerosol option depth (AOD) and tropospheric column NO2 (TroNO2). On the regional scale, SSD has an opposite trend from SDRP during 1960 to 2005, and the variation trends of regional mean values of SSD and SDRP in southeastern China are more pronounced than those in northwestern China. © 2015 Published by Elsevier B.V.