Investigation about the dependence of spectral diffuse-to-direct-beam irradiance ratio on atmospheric turbidity and solar zenith angle

Kaskaoutis, D. G.; Kambezidis, H. D.; Tóth, Z.
July 2007
Theoretical & Applied Climatology;2007, Vol. 89 Issue 3/4, p245
Academic Journal
The modifications of the solar spectral diffuse and direct-beam irradiances as well as the diffuse-to-direct-beam ratio, Edλ/Ebλ, as a function of the aerosol optical depth, AOD, and solar zenith angle, SZA, is investigated. The Edλ/Ebλ ratios decrease rapidly with wavelength and exponential curves in the form Edλ/Ebλ = aλ−b can be fitted with a great accuracy. These curves are strongly modified by the solar spectrum distribution, which is affected by the aerosol loading, aerosol optical properties and SZA. The spectral dependence of the above Edλ/Ebλ ratios in logarithmic coordinates does not yield a straight line, while a significant departure from the linearity is revealed. The reasons for this departure are investigated in detail and it is established that the aerosol physical properties such as single scattering albedo and size distribution along with the effect of SZA are responsible. These parameters strongly affect the scattering processes in the atmosphere and as a consequence the diffuse spectral distribution. The Edλ/Ebλ ratio, which is an indicator of the atmospheric transmittance (King, 1979), exhibits a strong wavelength and aerosol-loading dependence. The observed differences between turbid and clear atmospheres constitute a manifestation of contrasting air properties and influence solar irradiance spectra. The present work aims at investigating the effect of atmospheric turbidity and SZA on the Edλ/Ebλ ratio. For this reason, two distinct cases are examined: one having different atmospheric turbidity conditions but same SZA and a second having different SZAs and same atmospheric turbidity levels.


Related Articles

  • Comparison of the Ã…ngström parameters retrieval in different spectral ranges with the use of different techniques. Kaskaoutis, D. G.; Kambezidis, H. D. // Meteorology & Atmospheric Physics;Apr2008, Vol. 99 Issue 3/4, p233 

    Ground-based spectroradiometric measurements obtained in Athens have been used in order to derive the aerosol optical depth and the Ångström parameters. Their derivation is achieved using three well-established and widely used techniques; the Volz method, the direct method and the...

  • Solar occultation with SCIAMACHY: algorithm description and first validation. Meyer, J.; Bracher, A.; Rozanov, A.; Schlesier, A. C.; Bovensmann, H.; Burrows, J. P. // Advances in Geosciences;2005, Vol. 5, p17 

    This presentation concentrates on solar occultation measurements with the space-borne spectrometer SCIAMACHY in the UV-Vis wavelength range. Solar occultation measurements provide unique information about the vertical distribution of atmospheric constituents. For retrieval of vertical trace gas...

  • The Baseline The Solar Spectrum. Ball, David W. // Spectroscopy;Jun2005, Vol. 20 Issue 6, p30 

    Comments on the method applied in studying solar spectrometry in the U.S. Method used by astronomers at the Kitt Peak National Observatory in measuring the spectrum of the sun; Indication of chemical elements on the Sun absorbing light; Cause of dark lines found in rainbows.

  • The UV-A and visible solar irradiance spectrum: inter-comparison of absolutely calibrated, spectrally medium resolution solar irradiance spectra from balloon- and satellite-borne measurements. Gurlit, W.; Bösch, H.; Bovensmann, H.; Burrows, J. P.; Butz, A.; Camy-Peyret, C.; Dorf, M.; Gerilowski, K.; Lindner, A.; Noël, S.; Platt, U.; Weidner, F.; Pfeilsticker, K. // Atmospheric Chemistry & Physics;2005, Vol. 5 Issue 7, p1879 

    Within the framework of the ENVISAT/-SCIAMACHY satellite validation, solar irradiance spectra are absolutely measured at moderate resolution in the UV/visible spectral range (in the UV from 316.7-418 nm and the visible from 400-652 nm at a full width half maximum resolution of 0.55 nm and 1.48...

  • The Solar Spectral Irradiance from 200 to 2400 nm as Measured by the SOLSPEC Spectrometer from the Atlas and Eureca Missions. Thuillier, G.; Hersé, M.; Labs, D.; Foujols, T.; Peetermans, W.; Gillotay, D.; Simon, P. C.; Mandel, H. // Solar Physics;May2003, Vol. 214 Issue 1, p1 

    The SOLar SPECtrum (SOLSPEC) and the SOlar SPectrum (SOSP) spectrometers are two twin instruments built to carry out solar spectral irradiance measurements. They are made of three spectrometers dedicated to observations in the ultraviolet, visible and infrared domains. SOLSPEC flew with the...

  • Inter-comparison of stratospheric O3 and NO2 abundances retrieved from balloon borne direct sun observations and Envisat/SCIAMACHY limb measurements. Butz, A.; Bösch, H.; Camy-Peyret, C.; Chipperfield, M.; Dorf, M.; Dufour, G.; Grunow, K.; Jeseck, P.; Kühl, S.; Payan, S.; Pepin, I.; Pukite, J.; Rozanov, A.; Savigny, C. von; Sioris, C.; Wagner, T.; Weidner, F.; Pfeilsticker, K. // Atmospheric Chemistry & Physics Discussions;2005, Vol. 5 Issue 5, p10747 

    Stratospheric O3 and NO2 abundances measured by different remote sensing instruments are inter-compared: (1) Line-of-sight absorptions and vertical profiles inferred from solar spectra in the ultra-violet (UV), visible and infrared (IR) wavelength ranges measured by the LPMA/DOAS (Limb Profile...

  • Tungsten black absorber for solar light with wide angular operation range. Rephaeli, Eden; Fan, Shanhui // Applied Physics Letters;5/26/2008, Vol. 92 Issue 21, p211107 

    Using three-dimensional finite-difference time-domain simulations, we designed a structured tungsten slab with subwavelength periodicity that displays near-complete absorptivity throughout the entire solar spectrum over a wide angular range. The structure consists of a square lattice array of...

  • Himalayas: the Saudi Arabia of solar.  // New Scientist;10/22/2011, Vol. 212 Issue 2835, p20 

    The article reports on research published in "Environmental Science and Technology" by Kotaro Kawajiri and colleagues that mapped global solar irradiance levels, finding that the most ideal conditions for solar panels are in high-altitude locations such as the Himalaya and Andes mountains.

  • Solar irradiance in clear atmosphere: study of parameterisations of change with altitude. Oumbe, A.; Blanc, Ph.; Gschwind, B.; Lefevre, M.; Qu, Z.; Schroedter-Homscheidt, M.; Wald, L. // Advances in Science & Research;2011, Vol. 6, p199 

    The article presents a research study concerning the altitudinal change parameterizations in determining the solar irradiance in France. It mentions its significance in assessing the sun's irradiance depending on the level of the altitude. Researchers found out the parameterizations' time saving...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics