title: Traveling reference spectroradiometer for routine quality assurance of spectral solar ultraviolet irradiance measurements.
abstract: A transportable reference spectroradiometer for measuring spectral solar ultraviolet irradiance has been developed and validated. The expanded uncertainty of solar irradiance measurements with this reference spectroradiometer, based on the described methodology, is 8.8% to 4.6%, depending on the wavelength and the solar zenith angle. The accuracy of the spectroradiometer was validated by repeated site visits to two European UV monitoring sites as well as by regular comparisons with the reference spectroradiometer of the European Reference Centre for UV radiation measurements in Ispra, Italy. The spectral solar irradiance measurements of the Quality Assurance of Spectral Ultraviolet Measurements in Europe through the Development of a Transportable Unit (QASUME) spectroradiometer and these three spectroradiometers have agreed to better than 6% during the ten intercomparison campaigns held from 2002 to 2004. If the differences in irradiance scales of as much as 2% are taken into account, the agreement is of the order of 4% over the wavelength range of 300-400 nm.
authors.affiliation: European Reference Centre for Ultraviolet Radiation Measurements, Institute for Health and Consumer Protection, European Commission, Joint Research Centre, Ispra, Italy. julian.groebner@pmodwrc.ch
authors.forename: Julian
authors.initials: J
authors.lastname: Gröbner
authors.forename: Josef
authors.initials: J
authors.lastname: Schreder
authors.forename: Stelios
authors.initials: S
authors.lastname: Kazadzis
authors.forename: Alkiviadis F
authors.initials: AF
authors.lastname: Bais
authors.forename: Mario
authors.initials: M
authors.lastname: Blumthaler
authors.forename: Peter
authors.initials: P
authors.lastname: Görts
authors.forename: Rick
authors.initials: R
authors.lastname: Tax
authors.forename: Tapani
authors.initials: T
authors.lastname: Koskela
authors.forename: Gunther
authors.initials: G
authors.lastname: Seckmeyer
authors.forename: Ann R
authors.initials: AR
authors.lastname: Webb
authors.forename: Diana
authors.initials: D
authors.lastname: Rembges