A new look at solar dimming and brightening in China

Abstract

Published estimates on the magnitude of solar dimming and brightening in China show large discrepancies and inconsistencies in its seasonal variations. A nationwide reorganization of the surface solar radiation (SSR) network during 1990–1993 contributed to these uncertainties, which is reflected in a sudden upward jump in the published composite SSR time series. This jump is found to be prevalent in 23 out of 130 stations due to both natural (7 stations) and operational factors (16 stations). After eliminating the stations containing artifacts and discontinuous records, a new magnitude of solar dimming and brightening was estimated for China, and seasonal trends were determined. A transition from dimming to brightening remains in the SSR trend in China after excluding the affected stations and associated jump, in line with the global SSR trend.