Study Of Casleo Clear Sky Aerosol Loads In 2011 From One Year Of Aeronet Quality Assured Data

In this work we analyze one year observation of an Aeronet (GSFC-NASA Aerosol Robotic Network) sun-photometer installed on January 11, 2011 in CASLEO and being operational up to date. The main goal of placing the instrument in this location is to characterize the aerosol loads of this astronomical complex which is close and has the same sky characteristics of El Leoncito (31deg 43.33' South - 69deg 15.93' West, 2552 m ASL) one of the southern candidate site for Cherenkov Telescope Array (CTA). The low aerosol optical depth (AOD) annual mean of 0.038 measured at 500 nm shows exceptional clear sky quality. Data is compared with the measurements being done at Mauna Loa (19deg 32.34' North, 55deg 34.68' West, 3397 m ASL), where Aeronet reference instruments are being re-calibrated two to four times per year. Long term MODIS observations are studied, showing that the site is far enough to biomass burning transport regions to be affected by its influence.