Mean diurnal variations of cosmic ray intensity as measured by Andyrchi air shower array and Baksan underground scintillation telescope

TL;DR

This study analyzes diurnal variations in cosmic ray intensity using data from the Andyrchi air shower array and Baksan underground telescope, revealing effects of pressure, Earth's motion, and cosmic ray anisotropy.

Contribution

It provides new measurements of cosmic ray diurnal variations over multiple years and compares data from different detectors to understand anisotropy sources.

Findings

Solar diurnal wave influenced by pressure and Earth's motion

Cosmic ray anisotropy observed in sidereal diurnal wave

Consistent anisotropy signals across different energy ranges

Abstract

The results of measuring diurnal variations of extensive air showers with energy above 100 TeV detected by the Andyrchi air shower array in 1995-2002 are presented. It is shown that solar diurnal wave of intensity is formed by pressure variations and Compton-Getting effect (due to the orbital motion of the Earth). The data on cosmic ray anisotropy of the Baksan underground scintillation telescope (BUST) are also presented for energies above 2.5 TeV covering the period 1982-1998. The diurnal sidereal wave measured by both Andyrchi and BUST is due to anisotropy of the cosmic rays.