An effort to distinguish the effects of cloud cover and aerosols on the decadal variations of surface solar radiation in the Northern Hemisphere

Abstract

Surface solar radiation (SSR) serves as the primary energy source on Earth. However, a relative lack of research systematically quantifies long-term SSR variations and their driving factors based on complete and reliable baseline data. This paper presents a new assessment of the Northern Hemisphere/regional SSR variations and the influence of total cloud cover (TCC) on these variations, based on the latest reconstructed SSR gridded dataset. We also address multicollinearity among multiple aerosol types and quantify the effects of multiple aerosol/precursors on SSR variability using a partial least squares regression model. The results indicate that TCC is not the predominant driver of longer-term SSR variations, known as ‘dimming’ and ‘brightening’. The variations of NH _3 and SO _2 primarily drive inter-decadal SSR variations in North America, while the variations of SO _2 and NO _X mainly influence inter-decadal SSR variations in Europe.

Keywords

• SSR
• TCC
• aerosol/precursors
• PLSR model
• decadal variation