Quantitative effects of PM concentrations on spectral distribution of global normal irradiance

Daylight refers to a free and valuable resource exhibiting photometric and radiometric features, and the physical parameters commonly used to represent its features are irradiance and illuminance. They are both obtained by the spectral power distribution (SPD) of global irradiance, demonstrating that values noticeably affect indoor thermal and luminous environments. Nevertheless, outdoor particulate matter (PM) significantly affects SPD conditions, and two relative spectral notions, i.e., percentage of spectral irradiance (PSIr) and percentage of spectral illuminance (PSIl), were proposed to study the effects of PM10 concentrations in radiometry and photometry with a field measurement, Beijing. As a result, the strong impact of PM10 on PSIr/ PSIl can be noticed in the range (380 to 540 nm) (P-value