Erythemal radiation is the irradiance in W/m2 of biologically effective solar radiation measured over 280-320 nm's. It is derived using the Broadband UVB-1 Pyranometer. For more information about this instrument please see Instrumentation.
The data is downloaded in CSV format. Each set of data has a header. The header lines begin wth the # sign, and contains a description of location and data, along with possible data issues. The nighttime data is set to -9999 and data that are not currently available or associated with instrument errors are set to -9998.