Effects of stratocumulus, cumulus, and cirrus clouds on the UV-B Diffuse to Global Ratio: experimental and modeling results.

MARIA L. LÓPEZ; GUSTAVO G. PALANCAR; BEATRIZ M. TOSELLI

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2012 p. 461 - 461

roadband measurements of global and diffuse UV-B irradiance (280-315 nm) together with modeled and measured diffuse to global ratios (DGR) have been used to characterize the influence of different types of clouds on irradiance at the surface. Measurements were carried out during 2000-2001 in Córdoba City, Argentina. The Tropospheric Ultraviolet Visible (TUV) model was used to analyze the behavior of the modeled DGRs for different cloud optical depths and at different altitudes and solar zenith angles (SZA). Different cloud altitudes were also tested, although only the results for a cloud placed at 1.5-2.5 km of altitude are shown. A total of 16 days with stratocumulus, 12 with cumulus, and 16 with cirrus have been studied and compared among them and also against 21 clear sky days. Different behaviors were clearly detected and also differentiated through the analysis of the averages and the standard deviations of the DGRs: 1.02 ± 0.06 for stratocumulus, 0.74 ± 0.18 for cumulus, 0.63 ±