Spectral band resolution of solar radiation in Athens, Greece

✍ Scribed by C. P. Jacovides; G. B. Kallos; M. D. Steven

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 626 KB
• Volume: 13
• Category: Article
• ISSN: 0899-8418
• DOI: 10.1002/joc.3370130608

✦ Synopsis

Abstract

A 14‐year (1977–1990) record of global solar radiation measurements performed in Athens, Greece, has been utilized to determine the distribution of radiant energy in the various wavelength bands. The monthly mean values of the irradiation ratios in the spectral intervals, blue (0·380–0·525 μm), green‐orange (0·525–0·630 μm), red (0·630–0·710 μm), and photosynthetically active radiation (PAR) (0·380–0·710 μm) and the global irradiation (0·3–2·8 μm) compare favourably with values reported in the literature for different locations over a wide geographical area.

The irradiation ratios exhibit seasonal variations attributable to changes in local air‐mass climatology. It is observed that the proportion of the radiant energy in the various spectral bands relative to the global solar irradiation increases as sky conditions change from ‘clear’ to ‘partly cloudy’. Finally, the observed seasonal dependence of the broad‐band spectral energy distribution is essentially caused by changes in the composition of the air masses (turbidity, airborne pollutants, clouds) in residence at the measurement site in the course of the year.