Intercomparison of the parameterized Linke turbidity factor in deriving global horizontal irradiance

The Variation in Atmospheric Turbidity over a Tropical Site in Nigeria and Its Relation to Climate Drivers

“…In the atmosphere, solar radiation undergoes significant attenuation due to two primary mechanisms: scattering and absorption by air molecules, hydrometeors, and aerosol particles. These processes result in a remarkable reduction in the direct solar component and a moderate increase in the diffuse component [4,[6][7][8][9][10][11][12][13][14][15]. The attenuation processes of solar radiation exhibit significant variability due to factors such as the apparent motion of the sun, changes in meteorological conditions, and fluctuations in aerosol properties with time across different regions [8].…”

“…Generally, precise assessments of atmospheric turbidity require clear-sky spectral radiation data, which can be measured using spectroradiometers or multi-wavelength solar photometers. However, due to the limited availability and high cost of these sensors, turbidity is typically quantified, characterized, and estimated using broadband irradiance measurements, a more cost-effective method, and various turbidity factors and indices such as the Linke turbidity factor, the Ångström turbidity coefficient, the Schüepp turbidity factor, and the Unsworth-Monteith turbidity coefficient [14,15,20,35,38,39]. Among these, the most frequently used are the Linke turbidity factor (Linke, 1922) [40] and the Ångström turbidity coefficient [41].…”

“…Since the introduction of the Linke turbidity factor by [40] and the Ångström turbidity coefficient by [41], numerous researchers have proposed various models, including those by [22,45,[52][53][54][55][56][57][58]. These empirical equations have been used to quantify the impacts of air pollutants and aerosols on horizontal visibility degradation and the reduction in solar radiation received at the Earth's surface under different weather conditions and locations [4,6,8,11,[13][14][15]19,20,22,35,43,[59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74]. The extent of the application of all these indices at both regional and global scales remains unclear.…”