Fu Chuanbo, Dan Li, Chen Youlong, Tang Jiaxiang
Hainan Meteorological Observatory, Haikou 570203, China; Key Laboratory of Regional Climate-Environment Research for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province, Haikou 570203, China.
Key Laboratory of Regional Climate-Environment Research for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
J Environ Sci (China). 2015 Aug 1;34:206-11. doi: 10.1016/j.jes.2014.08.027. Epub 2015 Jun 11.
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 46 years. 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 46 years. The averaged SDRP over China has increased 2.33% per decade, while the averaged SSD shows a decrease of -0.13 hr/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 46 years, 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.
对1960 - 2005年期间7个城市群及整个中国晴天的日照时长（SD）和散射辐射百分比（定义为散射太阳辐射/总太阳辐射，DRP）的长期观测数据进行了分析。结果表明，在过去46年里，除了中国西北部的少数站点外，晴天日照时长（SSD）显著减少。在中国东部地区发现SSD明显下降，趋势系数低于 -0.8。伴随着SSD的下降，在这46年里，大多数站点的晴天散射辐射百分比（SDRP）呈现出明显的上升趋势。中国的平均SDRP每十年增加2.33%，而平均SSD则显示出每十年减少 -0.13小时/天。SDRP与SSD之间的相关系数为 -0.88。在过去46年里，城市群（从小型到大型城市群）的SSD均有所下降，尤其是在大城市和中等城市，这是由于以气溶胶光学厚度（AOD）和对流层柱状二氧化氮（TroNO2）为代表的强烈人为活动和空气污染所致。在区域尺度上，1960年至2005年期间，SSD与SDRP呈现相反的趋势，且中国东南部地区SSD和SDRP区域平均值的变化趋势比中国西北部地区更为明显。
