The G-Rad group was formed in a merger of the former CMDL’s STAR group and OAR/ARL’s former SRRB group on 1 Oct 2006 (see below). G-RAD is pursuing nearly all of the activities of those earlier groups. G-Rad is involved in empirical 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 (SURFRAD). In addition, we make observations of spectral solar radiation for the purpose of remote sensing of certain atmospheric constituents and determination of variations in the UV irradiance. Our research interests include the extent and cause of observed radiation and climate variations, and in collaborating with other research groups making satellite observations and climate model calculations. The various components and activities of G-Rad are given below. A relatively new program in the group is the absolute measurement of spectral solar UV for the investigation of the interaction of ozone and solar radiation.
- Observing Networks - The G-Rad group makes continuous measurements of surface radiation quantities at several field sites around the world and across the continental US, SURFRAD. Additionally, there is developing network concentrating on spectral UV within the US. The individual sites have varying characteristics and attributes and, therefore, are involved in different projects and applications. The emphasis is providing quality surface radiation measurements, and, in cooperation with NIST and the USDA, operating the Central Calibration and Test Facility for national UV monitoring instruments. Other efforts include research on the effects of surface UV radiation, improvement of surface radiation instruments and observing techniques, development of improved calibration and data quality control techniques, support for other national and international data collection programs, management of surface radiation networks, and basic research.
- Measurements & Instruments – Both broadband and spectrally select radiation measurements are made. Upwelling and downwelling broadband solar and thermal irradiances are measured as well as relative spectral direct solar measurements for purposes of determining aerosol optical depth and precipitable water are also made.
- Available Data - Raw data from the observing networks are centrally collected and processed in our Boulder office by the G-Rad staff. The field data have preliminary calibrations applied and initial data editing is preformed. The availability of the data varies as the processing completed for different sites and instruments. Individuals retrieving and using G-Rad data should acknowledge the NOAA/ESRL/G-Rad project or as indicated on the specific page from where the data are retrieved.
- Research Projects - The data collected from the observing network are used by the G-Rad group and its collaborators in a wide variety of research projects. Many of those projects are primarily related to the role of radiation and aerosols in climate variability and forcing. In addition, some field campaigns and laboratory investigations are conducted independently of the field network but generally relate to the common topic of radiation and climate.
- Calibration Facilities – G-Rad maintains basic independent but traceable calibration facilities for broadband solar, broadband IR, and spectral solar primarily in the UV
- Solar Calculators
CMDL - Climate Monitoring and Diagnostics Laboratory was combined with other NOAA laboratories, a branch, and a center in Boulder to become the new NOAA Earth System Research Laboratory. The personnel and programs of CMDL became the major part of the ESRL Global Monitoring Division
STAR and SRRB - The Solar and Terrestrial(or thermal) Atmospheric Radiation (STAR) group of CMDL was merged with the Surface Radiation Research Branch (SRRB) of ARL and has become the GMD-Radiation (G-Rad) group.
Some members from SRRB whose work was more closely related to Ozone research became associated with the GMD OZWV group