Analysis of the relationship between UV index and cloud optical depth intercomparing ground based and satellite measurements at Río Gallegos, South of Argentina.

FACUNDO ORTE, ELIAN WOLFRAM, JACOBO SALVADOR, RAÚL D?ELIA, N. PAES LEME, O. BONFILI, EDUARDO QUEL.

Foz do Iguassu, Brasil

Congreso; AGU Meeting of Americas; 2010

Environmental studies in the southern hemisphere are carried on by Lidar Division from CEILAP, with the financial support of JICA (Japan International Cooperation Agency) and the collaboration of IPSL, France. Lidar Division set up a ground based remote sensing site at Río Gallegos city (51º 36?S, 69º 19?W), at southern part of South America for measuring of stratospheric ozone, with lidar remote sensing techniques and passive sensor to measure solar UV irradiance. The Patagonian region is characterized by high cloud cover during day strongly changing the distribution of UV radiation that reaches the ground surface. For that reason some ozone hole passage are masked by cloud cover avoiding the increase in UVB radiation. The aim of this study is to analyze the influence of the cloud cover and cloud optical depth on the UV indexes, comparing ground based and satellites irradiance measurement. Solar UV radiation on the surface is measured with own instrument like a GUV multiband filter radiometer, YES radiometers and a Brewer spectraphotometer. As well, the cloud fraction from satellite platform OMI/NASA is compared with the cloud optical depth obtained from the synergy of radiative transfer model with GUV irradiance measurements taken over 2005-2007 periods.