The USDA UVB Monitoring Program is a sponsor and participant in this annual interagency intercomparison. The intercomparison takes place at the NOAA Table Mountain, Colorado SURFRAD site located outside of Boulder, Colorado. The intercomparisons are administered jointly by the National Institute of Standards and Technology (NIST) and the National Oceanic and Aeronautical Administration's (NOAA) Surface Radiation Research Branch.

The Canadian Brewer Network is run by the Experimental Studies Division (ARQX) of the Atmospheric Environment Service (AES), a part of Environment Canada. The network was established nearly 15 years ago to examine, measure, and monitor ozone and radiation in Canada. The automated ozone and UVB Brewer Ozone Spectrometer, designed and used by the network, is now considered to be a standard worldwide.

The USDA Network has collocated two fully instrumented climate stations with the Canadian network at Regina, Saskatchewan and Toronto, Ontario. The Regina site is additionally a Baseline Surface Radiation Network (BSRN) station. The BSRN is a project of the World Climate Research Programme (WCRP) aimed at detecting important changes in the earth's radiation field which may cause climate changes. The BSRN/WCRP is sponsored by the World Meteorological Organization (WMO), the International Council of Scientific Unions (ICSU) and Intergovernmental Oceanographic Commission (IOC) of UNESCO.

Sponsor:	Canadian Atmospheric Environmental Service
Locations Involved:	Bratt's Lake Observatory, Saskatchewan Toronto, Ontario
Period Of Intercomparison	December 3, 1997 - present, Bratt's Lake February 3, 1998 - present, Toronto
Publications:	none
Data Availability:	Contact each program

The UV Monitoring Network

The University of Georgia (UGA) operates this network of Brewer spectroradiometers for the US Environmental Protection Agency's (EPA) Office of Research and Development. The UV Monitoring Network is a cooperative effort between both the EPA and the National Park Service and is designed to provide these agencies with measurements of UV radiation, total column ozone, total column sulfur dioxide, optical density and stratospheric ozone profiles in support of ecological and health effects assessments. The UGA has located a Brewer within 47 km of the USDA's UVB climatological station at Big Bend National Park in Texas and both networks maintain permanent UV measurement instruments (UV-MFRSR and Brewer) at the CUCF calibration test site at Table Mountain, Colorado.

The National Oceanic and Atmospheric Administration's (NOAA) Office of Global Programs established the SURFRAD Network in 1993 through its Surface Radiation Research Branch with the intent of providing long-term global surface energy budgets in support of satellite measurement programs.

Broadband UVB pyranometers located at each of the collocated stations provide a permanent and ongoing study of the long-term comparability between the networks.

Sponsor:	National Oceanic and Atmospheric Administration
Locations Involved:	Bondville, IL and Fort Peck, MT
Period Of Intercomparison	November 22, 1994 - present, Bondville September 30, 1997 -present, Fort Peck
Publications:	none
Data Availability:	Contact each program

The Quantitative Links Network

Each program operated a VIS-MFRSR for a brief period of time and were therefore informally collocated. Soon after the USDA UVB program initiated monitoring, the Quantitative Links Network closed their collocated stations.

Sponsor:	US Department of Energy
Locations Involved:	Bondville, IL and Oxford, OH
Period Of Intercomparison:	November 22, 1994 - June 26, 1995 Bondville; December 14, 1994 - June 28, 1995 Oxford
Publications:	none
Data Availability:	Contact each program.