Sensitivity of erythemal UV/global irradiance ratios to atmospheric parameters: application for estimating erythemal radiation at four sites in Thailand

摘要: Factors affecting the ratio of erythemal UV (UVER) to broadband (G) irradiance were investigated in this study. Data from four solar monitoring sites Thailand, namely Chiang Mai, Ubon Ratchathani, Nakhon Pathom and Songkhla used investigate UVER/G response geometric atmospheric parameters. These comprised zenith angle, aerosol load, total ozone column, precipitable water clearness index. A modeling scheme was developed isolate examine effect each individual environmental parameter on ratio. Results showed that all parameters with exception angle index influenced ratios a linear manner. results also develop semi-empirical model for estimating hourly irradiance. 2009 2010 construct while validation performed using at above 2011. The reasonable agreement root mean square difference 13.5% bias − 0.5%, under sky conditions 10.9% 0.3%, respectively, cloudless conditions.