Characteristic Analysis of Sunshine Duration Change in China during the Last 50 Years

The sunshine duration daily data for 1956-2005, which was made available by the National Meteorological Information Center, is used to calculate sunshine duration trends, abrupt changes, temporal and spatial distribution, and seasonal variation through empirical orthogonal function (EOF) and Mann-Kendall analyses. The results show that: (1) Significant decreases in sunshine duration occurred over much of China during the latter half of the 20th century. The decreasing trend halted until the 1990s, after which time it was maintained at a low state. (2) Most of the meteorological stations happened abrupt climate change in 1980. (3) This change was significant, particularly in the eastern half of the country. (4) The change in summer sunshine duration is a major contributor to this decrease.