Abstract: Under the background of global warming, the gross radiation intensity on the ground changes obviously, thus the effects of the natural and human factors on solar radiation have become a hot issue. The characteristics of gross radiation intensity on the ground were analyzed from 1961 to 2009 in Datong using methods of a linear regression analysis, a Mann-Kendall test and a wavelet analysis. The abrupt change year, cycle feature and the future change trends of gross radiation intensity on the ground were revealed, and the relationship between solar radiation and meteorological factors was discussed. The results showed that the annual average gross radiation intensity on the ground is 5617.28 MJ/m² and it is in a significantly declining trend in the whole period from 1961 to 2009. However, it begins to rise slowly after 2000. The mutation of gross radiation intensity on the ground by M-K test occurs in 1975. There is a 9-year cycle for gross radiation intensity in Datong. Now, it is in the year of high solar radiation. The sunshine duration reduces yearly, and gross radiation intensity on the ground decreases, too. Both are in a significantly positive correlation. Precipitation decreases slowly with the fluctuation, so is gross radiation intensity on the ground. Both are also in a positive correlation. Cloud cover reduces yearly, while the correlation with the ground solar radiation is not significant. The correlation between the climatic elements and the ground solar radiation is not significant.

Key words: Solar radiation feature, Meteorological elements, Correlation, Datong