Researchers lead by principal investigator Ellsworth Dutton used more than 30 years of surface irradiance data obtained from Barrow, Alaska, in a study of temporal and spatial variations (Dutton et al. 2006). The high-temporal-resolution (1- to 3-minute averages) data and the quality-assured hourly averages are now available from the ARM Data Archive. See http://www.arm.gov/xdc/xds/noaarad for details or go here to order the data.