Direct and Standard Year Earth Radiation Data

Direct and Standard Year Earth Radiation Data is historical data set DSI-9723 archived at the National Climatic Data Center (NCDC). This data set consists of Direct Radiation and Standard Year Radiation (SYI) taken from SOLMET. SOLMET refers to the combination of solar radiation and meteorological data. This term is also used to identify the 27 stations that collected global horizontal data from 1951 through 1976. The SOLMET stations, included instruments that measure the global horizontal solar radiation and researchers modeled the direct beam solar radiation data. Each of the stations measured global horizontal solar radiation. Some of these stations made continuous recordings on strip charts; other stations only recorded the daily total energy (insulation) received. Much of these data were digitized at the station, using instructions that changed over the years, and were forwarded to regional centers (later centralized at the NCDC). During 1976, the network was essentially shut down while new equipment was purchased and installed. When these data were evaluated, only 27 stations were deemed suitable for inclusion in a national data base.