A Measurement of Time-Averaged Aerosol Optical Depth using Air-Showers Observed in Stereo by HiRes

Abstract

Air fluorescence measurements of cosmic ray energy must be corrected for attenuation of the atmosphere. In this paper we show that the air-showers themselves can yield a measurement of the aerosol attenuation in terms of optical depth, time-averaged over extended periods. Although the technique lacks statistical power to make the critical hourly measurements that only specialized active instruments can achieve, we note the technique does not depend on absolute calibration of the detector hardware, and requires no additional equipment beyond the fluorescence detectors that observe the air showers. This paper describes the technique, and presents results based on analysis of 1258 air-showers observed in stereo by the High Resolution Fly's Eye over a four year span.

7 pages, 3 figures, accepted for publication by Astroparticle Physics Journal

References in corpus (2)

• New measurement on photon yields from air and the application to the energy estimation of primary cosmic rays
• Techniques for measuring atmospheric aerosols at the High Resolution Fly's Eye experiment

Cited by in corpus (7)

• Indications of Proton-Dominated Cosmic Ray Composition above 1.6 EeV
• Measurement of the Flux of Ultra High Energy Cosmic Rays by the Stereo Technique
• Cosmic Rays: The Second Knee and Beyond
• The Rapid Atmospheric Monitoring System of the Pierre Auger Observatory
• Highest Energy Cosmic Rays and results from the HiRes Experiment
• Studies of systematic uncertainties in the estimation of the monocular aperture of the HiRes experiment
• Atmospheric effects in astroparticle physics experiments and the challenge of ever greater precision in measurements