G. Bernhard (Biospherical Instruments), and J. E. Frederick (U. Chicago) – Measurement of spectral irradiance between 280 and 600 nm with an SUV-150B spectroradiometer. The instrument is calibrated with standard lamps every two weeks. Observations started in August 2004.  The system has been part of the National Science Foundation’s Arctic Observing Network and was decommissioned in August 2017 due to the lack of funds.  The system is undergoing refurbishment at the factory for possible relocation at a yet-to-be-determined location.