Theoretical and Applied Climatology

, Volume 48, Issue 1, pp 23–27

Relationships of photosynthetically active radiation and shortwave irradiance

Authors

  • G. Papaioannou
    • Department of Applied Physics, Laboratory of MeteorologyUniversity of Athens
  • N. Papanikolaou
    • Institute of Meteorology and Physics of the Atmospheric EnvironmentNational Observatory of Athens
  • D. Retalis
    • Institute of Meteorology and Physics of the Atmospheric EnvironmentNational Observatory of Athens
Article

DOI: 10.1007/BF00864910

Cite this article as:
Papaioannou, G., Papanikolaou, N. & Retalis, D. Theor Appl Climatol (1993) 48: 23. doi:10.1007/BF00864910

Summary

Hourly measurements of solar irradiance in the wave band excluding photosynthetically active radiation (PAR) and solar irradiance (SI) were made over a 12-month period at the National Observatory of Athens, for obtaining the ratios of PAR to SI. These irradiance ratios exhibit dependence on sky conditions, with slightly larger values being observed under “cloudy” skies and seasonal variations, attributable to changes in local air mass climatology. The highest values have been obtained during the growing season (April–September). The mean annual value of 0.473 observed for the irradiance ratio in the PAR band compares favorably with values reported in the literature for different locations over a wide geographical area.

Copyright information

© Springer-Verlag 1993