Earth Systems Research Laboratory Global Radiation Surface Radiation Budget (SURFRAD) Quality Control Radiation (QCRAD) Level 3 Measurements

The Global Radiation and Aerosol (GRAD) Group is part of NOAA's Earth System Research Laboratory (ESRL) in Boulder, CO. The GRAD Group is involved in observational and theoretical research of the Earth's surface and atmospheric radiation budgets. The group specializes in the investigation of climatically significant variations in long-term radiation and meteorological measurements made at diverse globally-remote sites and continental US sites. The GRAD Observation Network is comprised of ESRL Global Monitoring Division (GMD) Baseline Observatories, GMD Baseline Surface Radiation Network (BSRN) sites, Surface Radiation (SURFRAD) sites in the continental United States, Global Atmospheric Watch (GAW) international sites, NOAA/EPA Brewer Spectrophotometer Network (NEUBrew) sites in the continental United States, Antarctic UV sites, and Solar Radiation (SOLRAD) sites in the continental United States. In addition to measurements made at GRAD Observation Network sites, the group makes observations of spectral solar radiation for the remote sensing of certain atmospheric constituents and determination of variations in the UV irradiance. Group research interests include the extent and cause of observed radiation and climate variations and collaborations with other research groups to make satellite observations and climate model calculations as accurate as possible.

Accurate and precise ground-based measurements in differing climatic regions are essential to refine and verify satellite-based estimates. To fill this need, the Surface Radiation Budget Network (SURFRAD) was established in 1993 as the first full surface radiation budget network operating across the United States with a primary object to support climate research with accurate, continuous, long-term measurements of the surface radiation budget over the United States. There are seven SURFRAD stations that operate in climatologically diverse regions: Colorado, Illinois, Nevada, Montana, Mississippi, Pennsylvania, and South Dakota. The SURFRAD network collects independent measures of upwelling and downwelling radiation, solar and infrared radiation, ancillary observations include direct and diffuse solar, photosynthetically active radiation, erythemal UVB, spectral solar, and meteorological parameters. Data are downloaded, quality controlled, and processed into daily files that are distributed in near real time by anonymous FTP and the web. Observations from SURFRAD have been used for evaluating satellite-based estimates of surface radiation, and for validating hydrologic, weather prediction, and climate models while working closely with other universities, national labs, and scientific programs.