Comparison of UV-RSS spectral measurements and TUV model runs for clear skies for the May 2003 ARM aerosol intensive observation period
Open Access
- 26 March 2008
- journal article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 8 (6), 1813-1821
- https://doi.org/10.5194/acp-8-1813-2008
Abstract
The first successful deployment of the fully-operational ultraviolet rotating shadow-band spectroradiometer occurred during the May 2003 US Department of Energy's Atmospheric Radiation Measurement program's Aerosol Intensive Observation Period. The aerosol properties in the visible range were characterized using redundant measurements with several instruments to determine the column aerosol optical depth, the single scattering albedo, and the asymmetry parameter needed as input for radiative transfer calculations of the downwelling direct normal and diffuse horizontal solar irradiance in clear-sky conditions. The Tropospheric Ultraviolet and Visible (TUV) radiative transfer model developed by Madronich and his colleagues at the US National Center for Atmospheric Research was used for the calculations of the spectral irradiance between 300–360 nm. Since there are few ultraviolet measurements of aerosol properties, most of the input aerosol data for the radiative transfer model are based on the assumption that UV input parameters can be extrapolated from the visible portion of the spectrum. Disagreements among available extraterrestrial spectra, which are discussed briefly, suggested that instead of comparing irradiances, measured and modeled spectral transmittances between 300–360 nm should be compared for the seven cases studied. Transmittance was calculated by taking the ratios of the measured irradiances to the Langley-derived, top-of-the-atmosphere irradiances. The cases studied included low to moderate aerosol loads and low to high solar-zenith angles. A procedure for retrieving single scattering albedo in the ultraviolet based on the comparisons of direct and diffuse transmittance is outlined.Keywords
This publication has 26 references indexed in Scilit:
- The Spectral Irradiance Monitor: Scientific Requirements, Instrument Design, and Operation ModesPublished by Springer Science and Business Media LLC ,2007
- Version 2 data of the National Science Foundation's Ultraviolet Radiation Monitoring Network: South PoleJournal of Geophysical Research: Solid Earth, 2004
- Further developments in closure experiments for surface diffuse irradiance under cloud‐free skies at a continental siteGeophysical Research Letters, 2004
- The sun’s total and spectral irradiance for solar energy applications and solar radiation modelsSolar Energy, 2004
- Ground‐based determination of the spectral ultraviolet extraterrestrial solar irradiance: Providing a link between space‐based and ground‐based solar UV measurementsJournal of Geophysical Research: Solid Earth, 2001
- MODTRAN4: radiative transfer modeling for remote sensingPublished by SPIE-Intl Soc Optical Eng ,2000
- Comparison of model‐estimated and measured diffuse downward irradiance at surface in cloud‐free skiesJournal of Geophysical Research: Solid Earth, 2000
- Accuracy assessments of aerosol optical properties retrieved from Aerosol Robotic Network (AERONET) Sun and sky radiance measurementsJournal of Geophysical Research: Solid Earth, 2000
- SPECTRAL ALBEDO MEASUREMENTS IN THE UV and VISIBLE REGION OVER DIFFERENT TYPES OF SURFACESPhotochemistry and Photobiology, 1995
- Line‐by‐line calculations of atmospheric fluxes and cooling rates: Application to water vaporJournal of Geophysical Research: Solid Earth, 1992