New Spectroradiometers Complying with the NDSC Standards

Abstract

The investigation of the effect of solar ultraviolet (UV) and visible radiation on biological organisms and photochemical reactions requires spectral measurements of the desired radiation parameters of high accuracy. The Network for the Detection of Stratospheric Change (NDSC) and the World Meteorological Organization have set up stringent requirements for high-quality spectral measurements of ultraviolet radiation. It is shown that two new instruments comply with these standards. One is the newly developed spectroradiometer of the Institute of Meteorology and Climatology, University of Hannover, Hannover, Germany. It is capable of covering the spectral range from the UV to the near-infrared (290?1050 nm) in a comparably fine resolution. One major aim is to deploy this instrument as a traveling NDSC spectroradiometer. The other new instrument is built for the U.S. National Science Foundation's UV Monitoring Network. It is designed to monitor UV and visible irradiance at high latitudes and covers a wavelength range from 280 to 600 nm. Data of both instruments show deviations of less than 5% for a wide range of atmospheric conditions compared to a NDSC spectroradiometer owned by the Climate Monitoring and Diagnostics Laboratory during the fifth North American Interagency Intercomparison for UV Spectroradiometers. Such deviations represent state-of-the-art instrumentation for conducting long-term measurements of solar UV radiation capable of detecting trends and supporting long-term measurements by traveling standards. Furthermore, there is now an instrument capable of measuring solar irradiance in a wavelength range from 250 to 1050 nm.