Factors affecting the surface radiation trends over China between 1960 and 2000

In this paper, the surface solar radiation data from 1960 to 2000 gathered from 40 weather stations over China were reexamined, and the relationship of long-term trends of the solar radiation and climate factors were analyzed. The results indicate that the surface solar radiation in most regions of China begins to increase after 1990. Decreases in cirrus and cirrostratus clouds, which account for a larger percentage of the total cloud amount over China, have an important contribution to the increasing trend of the surface solar radiation. Further examination of the surface water vapor changes reveals that the surface solar radiation negatively correlates with the near surface water vapor in most region of China, and this negative correlation is more pronounced in higher latitudes of China where the atmosphere is compared to regions in southern China.

► Alto-clouds have a large impact on surface solar radiation trends over China.
► Aerosols are not the main factor affecting solar radiation trends over China.
► The surface solar radiation negatively correlates with water vapor in dry regions.