Description of Atmospheric Conditions at the Pierre Auger Observatory Using Meteorological Measurements and Models

TL;DR

This paper details the atmospheric monitoring methods at the Pierre Auger Observatory, including balloon measurements, monthly models, and weather prediction data, crucial for accurate cosmic ray air shower reconstruction.

Contribution

It introduces a comprehensive atmospheric monitoring system combining balloon data, monthly models, and weather prediction models for improved air shower analysis.

Findings

Development of monthly atmospheric models for the observatory

Implementation of a rapid monitoring system triggered by high-energy events

Transition from balloon launches to weather prediction models for atmospheric data

Abstract

Atmospheric conditions at the site of a cosmic ray observatory must be known well for reconstructing observed extensive air showers, especially when measured using the fluorescence technique. For the Pierre Auger Observatory, a sophisticated network of atmospheric monitoring devices has been conceived. Part of this monitoring was a weather balloon program to measure atmospheric state variables above the Observatory. To use the data in reconstructions of air showers, monthly models have been constructed. Scheduled balloon launches were abandoned and replaced with launches triggered by high-energetic air showers as part of a rapid monitoring system. Currently, the balloon launch program is halted and atmospheric data from numerical weather prediction models are used. A description of the balloon measurements, the monthly models as well as the data from the numerical weather prediction are presented.