The 1994 North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers.
Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. To assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks, the first North American Intercomparison of Ultraviolet Monitoring Spectroradiometers was held September 19-29, 1994 at Table Mountain outside Boulder, Colorado, USA. This Intercomparison was coordinated by the National Institute of Standards and Technology and the National Oceanic and Atmospheric Administration (NOAA). Participating agencies were the Environmental Protection Agency, National Science Foundation, Smithsonian Environmental Research Center, and Atmospheric Environment Service, Canada. Instruments were characterized for wavelength accuracy, bandwidth, stray-light rejection, and spectral irradiance responsivity, the latter with a NIST standard lamp calibrated to operate in the horizontal position. The spectral irradiance responsivity was determined once indoors and twice outdoors, and demonstrated that, while the responsivities changed upon moving the instruments, they were relatively stable when the instruments remained outdoors. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST standard lamp, and a simple convolution technique to account for the different bandwidths of the instruments, the measured solar irradiances agreed within 5 %.
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA.
Ambler
A
Thompson
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA.
Edward A
EA
Early
National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80303, USA.
John
J
DeLuisi
National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80303, USA.
Patrick
P
Disterhoft
Atmospheric Environment Service, Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada.
David
D
Wardle
Atmospheric Environment Service, Environment Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada.
James
J
Kerr
Dept. Physics and Astronomy, University of Georgia, Athens, GA 30602, USA.
John
J
Rives
Dept. Physics and Astronomy, University of Georgia, Athens, GA 30602, USA.
Yongchen
Y
Sun
Biospherical Instruments Inc., 5340 Riley Street, San Diego, CA 92110-2621, USA.
Timothy
T
Lucas
Biospherical Instruments Inc., 5340 Riley Street, San Diego, CA 92110-2621, USA.
Tanya
T
Mestechkina
Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037, USA.
Patrick
P
Neale
environmental monitoring; intercomparison; solar ultraviolet; spectroradiometers