Pierre Auger Observatory - cloud monitoring system 

The Pierre Auger Observatory, located in Argentina, is devoted to the study of ultra-high energy cosmic rays. The Observatory is a scientific collaboration between 18 countries around the world and the University of Adelaide is currently the only Australian university with scientists in the collaboration.

The Pierre Auger Observatory was initially funded under the Australian Government's Education Investment Fund (EIF) and received further funds as part of the Australian Government's National Collaborative Research Infrastructure Strategy (NCRIS).

The Observatory operates with water tanks fitted with 1600 detectors that detect Cherenkov light and allow the number of particles in each cosmic ray shower to be determined. Four sites, each containing six UV telescopes, view nitrogen fluorescence light from incoming cosmic ray showers over the 3000 km2area of the Observatory. Each of those sites comprise six 4-metre diameter Schmidt telescopes, each with approximately 500 photomultiplier tubes and an elevation range of 2-30o.

Australia, through the University of Adelaide, is playing a central role in the Observatory, based on its long experience in high energy astrophysics and, particularly, in the atmospheric fluorescence techniques employed by the optical detectors of the Observatory.

Pierre Auger

A Pierre Auger Observatory surface detector station with the Andes in the background. Image credit: www.auger.org

Atmospheric monitoring

The University of Adelaide's leads data analysis work, observing shifts, and, importantly, atmospheric monitoring, a critical service task for the Observatory. Atmospheric monitoring is important since the fluorescence detectors often view cosmic ray air showers at distances of over 30 km and corrections must be made for cloud obscuration and the absorption and scattering of the light by molecules and aerosols. Thus the presence of night-time cloud must be monitored over the full Observatory area.

Using EIF funding, the University of Adelaide built four new cloud monitoring systems for the Observatory, which were commissionied in 2013. Each of the four new cloud cameras scans across the field of view of each fluorescence detector telescope, plus surrounding areas of sky, using a commercial pan-and-tilt platform as used in security camera applications. The images thus produced will provide both data on cloud cover for each fluorescence telescope pixel and real-time all-sky cloud images for observers. Using NCRIS funding, the University of Adelaide can operate and maintain the cloud detectors until 30 June 2017.

Pierre Auger observatory fact sheet

Key Contacts

Prof Roger Clay and Prof Bruce Dawson, University of Adelaide.