Daily Solar Radiation

Daily Solar Radiation Data is historical data set DSI-9726 archived at the National Climatic Data Center (NCDC). Elements included are total radiation per day (Langley's), total extraterrestrial radiation, minutes/percent of possible of sunshine, average cloudiness and percent of possible radiation. The dataset covers stations in the United States, Canada, Iceland, West Indies, and the Pacific Islands. Four stations have records beginning December 1, 1951. The majority of stations began taking records in July of 1952. The period of record ends in December 1976. Stations measuring hemispheric solar radiation had a pyrheliometer installed in a suitable exposed location and a recorder installed in the office. Thermo-electric hemisphere pyrheliometers were used in measuring hemispheric solar radiation. Two types were in use: A 10-Junction type in general use, and a more sensitive 50-Junction type used at selected northern stations during months when solar radiation is less intense. Beginning in 07/01/57, solar radiation data was recorded in the international pyrheliometer scale of 1956. This scale provides values that are 2.0% less than those based on the Smithsonian Scale of 1913, the standard previously in use.