title: The 1997 North American Interagency Intercomparison of Ultraviolet Spectroradiometers Including Narrowband Filter Radiometers.
abstract: The fourth North American Intercomparison of Ultraviolet Monitoring Spectroradiometers was held September 15 to 25, 1997 at Table Mountain outside of Boulder, Colorado, USA. 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. The main purpose of the Intercomparison was to assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks. This Intercomparison was coordinated by NIST and NOAA, and included participants from the ASRC, EPA, NIST, NSF, SERC, USDA, and YES. The UV measuring instruments included scanning spectroradiometers, spectrographs, narrow band multi-filter radiometers, and broadband radiometers. Instruments were characterized for wavelength accuracy, bandwidth, stray-light rejection, and spectral irradiance responsivity. The spectral irradiance responsivity was determined two to three times outdoors to assess temporal stability. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST traceable standard lamp, and a simple convolution technique with a Gaussian slit-scattering function to account for the different bandwidths of the instruments, the measured solar irradiance from the spectroradiometers excluding the filter radiometers at 16.5 h UTC had a relative standard deviation of ±4 % for wavelengths greater than 305 nm. The relative standard deviation for the solar irradiance at 16.5 h UTC including the filter radiometer was ±4 % for filter functions above 300 nm.
authors.affiliation: Cooperative Institute for Research in Environmental Studies, University of Colorado, Boulder, CO 80309, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Lantz
authors.affiliation: Cooperative Institute for Research in Environmental Studies, University of Colorado, Boulder, CO 80309, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Disterhoft
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Early
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA.
authors.forename: Ambler
authors.initials: A
authors.lastname: Thompson
authors.affiliation: National Oceanic and Atmospheric Administration, David Skaggs Research Bldg., 325 Broadway, Boulder, CO 80303, USA.
authors.forename: John
authors.initials: J
authors.lastname: DeLuisi
authors.affiliation: Atmospheric Sciences Research Center, State University of New York, Albany, 251 Fuller Road, Albany, NY 12203, USA.
authors.forename: Jerry
authors.initials: J
authors.lastname: Berndt
authors.affiliation: Atmospheric Sciences Research Center, State University of New York, Albany, 251 Fuller Road, Albany, NY 12203, USA.
authors.forename: Lee
authors.initials: L
authors.lastname: Harrison
authors.affiliation: Atmospheric Sciences Research Center, State University of New York, Albany, 251 Fuller Road, Albany, NY 12203, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Kiedron
authors.affiliation: Biospherical Instruments Inc., 5340 Riley Street, San Diego, CA 92110-2621, USA.
authors.forename: James
authors.initials: J
authors.lastname: Ehramjian
authors.affiliation: Biospherical Instruments Inc., 5340 Riley Street, San Diego, CA 92110-2621, USA.
authors.forename: Germar
authors.initials: G
authors.lastname: Bernhard
authors.affiliation: Biospherical Instruments Inc., 5340 Riley Street, San Diego, CA 92110-2621, USA.
authors.forename: Lauriana
authors.initials: L
authors.lastname: Cabasug
authors.affiliation: Biospherical Instruments Inc., 5340 Riley Street, San Diego, CA 92110-2621, USA.
authors.forename: James
authors.initials: J
authors.lastname: Robertson
authors.affiliation: National Ultraviolet Monitoring Center, University of Georgia, Athens, GA 30602, USA.
authors.forename: Wanfeng
authors.initials: W
authors.lastname: Mou
authors.affiliation: National Ultraviolet Monitoring Center, University of Georgia, Athens, GA 30602, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Taylor
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: James
authors.initials: J
authors.lastname: Slusser
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: David
authors.initials: D
authors.lastname: Bigelow
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Bill
authors.initials: B
authors.lastname: Durham
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: George
authors.initials: G
authors.lastname: Janson
authors.affiliation: Smithsonian Environmental Research Center, P.O. Box 28, Edgewater, MD 21037, USA.
authors.forename: Douglass
authors.initials: D
authors.lastname: Hayes
authors.affiliation: Yankee Environmental Systems, 101 Industrial Road, P.O. Box 746, Turners Falls, MA 01376, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Beaubien
authors.affiliation: Yankee Environmental Systems, 101 Industrial Road, P.O. Box 746, Turners Falls, MA 01376, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Beaubien
keywords: environmental monitoring; intercomparison; solar ultraviolet; spectroradiometers