A. Aab, Universität Siegen
P. Abreu, Instituto Superior Técnico
M. Aglietta, Università degli Studi di Torino
M. Ahlers, University of Wisconsin-Madison
E. J. Ahn, Fermi National Accelerator Laboratory
I. F.M. Albuquerque, Universidade de São Paulo
I. Allekotte, Centro Atomico Bariloche
J. Allen, New York University
P. Allison, The Ohio State University
A. Almela, Universidad Nacional de San Martín
J. Alvarez Castillo, Universidad Nacional Autónoma de México
J. Alvarez-Muñiz, Universidad de Santiago de Compostela
R. Alves Batista, Universität Hamburg
M. Ambrosio, Università degli Studi di Napoli Federico II
A. Aminaei, Radboud Universiteit
L. Anchordoqui, University of Wisconsin-Milwaukee
S. Andringa, Instituto Superior Técnico
T. Anticic, Institute Ruder Boskovic
C. Aramo, Università degli Studi di Napoli Federico II
F. Arqueros, Universidad Complutense de Madrid
H. Asorey, Centro Atomico Bariloche
P. Assis, Instituto Superior Técnico
J. Aublin, Laboratoire de Physique Nucléaire et de Hautes Energies
M. Ave, Universidad de Santiago de Compostela
M. Avenier, Laboratoire de Physique Subatomique et de Cosmologie de Grenoble
G. Avila, Comision Nacional de Energia Atomica Argentina
A. M. Badescu, University Politehnica of Bucharest
K. B. Barber, The University of Adelaide
R. Bardenet, Universite Paris-Saclay
J. Bäuml, Karlsruher Institut für Technologie, Campus Nord
C. Baus, Karlsruher Institut für Technologie, Campus Süd
J. J. Beatty, The Ohio State University
K. H. Becker, Bergische Universität Wuppertal

Document Type


Publication Date



The Pierre Auger Observatory is making significant contributions towards understanding the nature and origin of ultra-high energy cosmic rays. One of its main challenges is the monitoring of the atmosphere, both in terms of its state variables and its optical properties. The aim of this work is to analyse aerosol optical depth τa(z) values measured from 2004 to 2012 at the observatory, which is located in a remote and relatively unstudied area of Pampa Amarilla, Argentina. The aerosol optical depth is in average quite low - annual mean τa(3.5km)~0.04 - and shows a seasonal trend with a winter minimum - τa(3.5km)~0.03 -, and a summer maximum - τa(3.5km)~0.06 -, and an unexpected increase from August to September - τa(3.5km)~0.055. We computed backward trajectories for the years 2005 to 2012 to interpret the air mass origin. Winter nights with low aerosol concentrations show air masses originating from the Pacific Ocean. Average concentrations are affected by continental sources (wind-blown dust and urban pollution), whilst the peak observed in September and October could be linked to biomass burning in the northern part of Argentina or air pollution coming from surrounding urban areas. © 2014 Elsevier B.V.

Publication Source (Journal or Book title)

Atmospheric Research

First Page


Last Page