Atmospheric Aerosol Attenuation Measurements at the Pierre Auger Observatory

摘要

The Fluorescence Detector (FD) of the Pierre Auger Observatory provides anearly calorimetric measurement of the primary particle energy, since thefluorescence light produced is proportional to the energy dissipated by anExtensive Air Shower (EAS) in the atmosphere. The atmosphere therefore acts asa giant calorimeter, whose properties need to be well known during data taking.Aerosols play a key role in this scenario, since their effect on lighttransmission is highly variable even on a time scale of one hour, and thecorresponding correction to EAS energy can range from a few percent to morethan 40%. For this reason, hourly Vertical Aerosol Optical Depth (taer(h))profiles are provided for each of the four FD stations. Starting from 2004, upto now 9 years of taer(h) profiles have been produced using data from theCentral Laser Facility (CLF) and the eXtreme Laser Facility (XLF) of the PierreAuger Observatory. The two laser facilities, the techniques developed tomeasure taer(h) profiles using laser data and the results will be discussed.