Atmospheric Aerosol Attenuation Measurements at the Pierre Auger Observatory

Understand

The Fluorescence Detector (FD) of the Pierre Auger Observatory provides a nearly calorimetric measurement of the primary particle energy, since the fluorescence light produced is proportional to the energy dissipated by an Extensive Air Shower (EAS) in the atmosphere.

• The atmosphere therefore acts as a giant calorimeter, whose properties need to be well known during data taking.
• Aerosols play a key role in this scenario, since their effect on light transmission is highly variable even on a time scale of one hour, and the corresponding correction to EAS energy can range from a few percent to more than 40%.
• For this reason, hourly Vertical Aerosol Optical Depth (taer(h)) profiles are provided for each of the four FD stations.