Comparison of global ultraviolet (290–385 nm) and global irradiation measured during the warm season in valencia, spain

Abstract

This paper studies data of ultraviolet (290-385 nm band) horizontal solar irradiation and global horizontal solar irradiation measured at Valencia (Spain) during the period March 1991 to September 1991. Analysis of error estimations and correlation coefficients show that the 10 minute, hourly, and daily values of ultraviolet (UV) and global irradiation are highly correlated. Improved figures and less dependence on location are achieved by defining a clearness index for the UV 290-385 nm band and relating it to the conventional whole-band clearness index. The novel clearness index obtained from Valencia data is approximately half of the conventional clearness index. Considering solar elevation as an additional parameter, the correlation coefficients increase to values in the 094 to 096 interval for solar elevations greater than SS", both for hourly and 10-minute values.

UV and global solar radiation in Łódź, Central Poland

“…In Europe, analyses of short-term variability of broadband UV radiation have been undertaken at: Potsdam (Germany), (Feister and Grasnick, 1992); Valencia (Spain), (Martinez-Lozano and Casanovas, 1994;Martinez-Lozano et al, 1996;Martinez-Lozano et al, 1999); Bratislava (Slovakia), (Zavodska and Reichrt, 1985); Jungfraujoch (Switzerland), (Ambach et al, 1991, Blumthaler et al, 1994; and Granada (Spain), (FoyoMoreno et al, 1998). In Poland, the monitoring of UV radiation focuses on erythemally weighted UV in rural areas (Belsk since 1976, Łeba, Legionowo, Kasprowy Wierch since 1993.…”

The erythemal clearness index for Valencia, Spain

“…The true physical value of the clearness index is instantaneous although it can be used also with hourly values Ogunjobi and Kim, 2004), daily values (Martínez-Lozano et al, 1994a;Kudish and Ianetz, 1996;Ulgen and Hepbasli, 2002;Santos et al, 2003) or monthly values (Udo, 2000;Ulgen and Hepbasli, 2002;Kudish et al, 2005). In order to study the total UV radiation, Martínez-Lozano et al (1994b) defined an ultraviolet clearness index k tUV , with a similar form to k t but referring only to the UV spectral range and using the solar constant for UV radiation, I SCUV (81.13 Wm −2 ) obtained from the SUSIM Atlas 3 extraterrestrial spectrum (http://www.solar.nrl.navy.mil/susim atlas data. htm).…”

Impact of Cloud Cover on Global UV Irradiance over Baghdad, Iraq

“…The increase of UV/G with cloud cover is greater for lower solar elevations and thus for over cast conditions the mean UV/G value does not depend on the solar elevation analysis. To study this relationship furthermore the index K tuv was analyzed, this index is defined as the ratio between the UV irradiance reaching the surface level and the corresponding extraterrestrial flux UV ext [18], that is:…”

“…Solar UV radiation is usually divided into three bands UV-C (100-280 nm) which is completely absorbed by stratospheric ozone; UV-B (280-315 nm) which is only partially absorbed or scattered in the atmosphere and UV-A (315-400 nm) which makes up most of the UV radiation received at the earth's surface [1][2][3][4][5][6][7][8]. In outer space, UV-B and UV-A band represent only 7.45% of the total solar radiation [9].…”