Ratio of UV to global broad band irradiation in Valencia, Spain

Abstract

This paper presents the results of an analysis of 6 years of measurements of UV and broad band irradiation values in Valencia, Spain. Hourly and daily integrated UV irradiance, ITUV, measured by a TUVR Eppley radiometer, and global irradiance IT from a Kipp‐Zonen CM‐11 pyranometer, were highly correlated, with ITUV/IT percentages varying from 2.9% to 3.5% for hourly values and from 2.9% to 3.4% for daily values. If a general linear relation ITUV=mIT is considered, the correlation coefficient r is always greater than 0.96 for hourly values and 0.91 for daily values. However, the relation between ITUV/IT and the clearness index kT is poorly correlated, although improved results, with less dependence on a specific location, can be observed using the kTUV and kT clearness indices. For a general linear relation, kTUV=mkT, the correlation coefficient r is always greater than 0.89 for hourly values and 0.86 for daily values. Copyright © 1999 Royal Meteorological Society

The erythemal clearness index for Valencia, Spain

“…This contrasts with the situation for the k t,m or the k tUV,m values (Martínez-Lozano et al, 1999). The statistics values of the monthly erythemal clearness index, Table I.…”

“…When we eliminate the values corresponding to higher zenith angles, the k t tends to present a nearly constant value (Martínez-Lozano et al, 1999). The k t reaches Figure 4.…”

“…The TUVR is regularly calibrated at the IER (Renewable Energy Institute of CIEMAT) and also periodically in the Eppley laboratories by reference to an absolute cavity radiometer. The inaccuracy of the pyranometer for outdoor measurements is below 15% (Mehos et al, 1991;Martínez-Lozano et al, 1999).…”

UV and global solar radiation in Łódź, Central Poland

“…optical thickness, liquid water content, droplets size and location in the sky. Generally, UV radiation reaching the Earth's surface in Europe does not exceed 5% of global solar radiation under cloud-free sky conditions; however, this does vary spatially and temporally (Feister and Grasnick, 1992;Martinez-Lozano et al, 1999). Knowledge of the amount of UV radiation reaching the Earth's surface is important given UV is known to be an agent in photobiological phenomena such as bactericidal effects, melanogenic and erythogenic processes (skin pigment, redness of skin etc.…”

Selection of cloudless sky conditions by applying solar global ultraviolet irradiance measurements

“…For the UV band it was called k tUV , and it was correlated with broadband k t , UV, and broadband irradiance measurements (Foyo Moreno et al 1999, Martínez Lozano et al 1994, Martínez Lozano et al 1999, Cañada et al 2000, Cañada et al 2003, Ogunjobi and Kim 2004, Bo et al 2010). But it is important to remark that the extraterrestrial solar constant between the wavelengths 290295 to 385 nm, obtained from the spectrum of Gueymard (2004), reaches a value of 83.80280.985 W/m 2 .…”