Cosmic ray flux and lockdown due to COVID19 in Kolkata -- any correlation?

TL;DR

This study measures cosmic ray muon flux in Kolkata before and after COVID-19 lockdown to investigate potential correlations with atmospheric pollution changes caused by restricted human activity.

Contribution

It provides the first comparative analysis of cosmic ray flux and atmospheric pollutants in Kolkata related to COVID-19 lockdown effects.

Findings

Cosmic ray flux showed measurable differences before and after lockdown.

Significant reduction in air pollutants was observed during lockdown.

Data suggests atmospheric conditions may influence cosmic ray detection.

Abstract

Cosmic ray muon flux is measured by the coincidence technique using plastic scintillation detectors in the High Energy Physics detector laboratory at Bose Institute, Kolkata. Due to the COVID19 outbreak and nationwide complete lockdown, the laboratory was closed from the end of March 2020 till the end of May 2020. After lockdown, although the city is not in its normal state, we still were able to take data on some days. The lockdown imposed a strict restriction on the transport service other than the emergency ones and also most of the industries were shut down in and around the city. This lockdown has significant effect on the atmospheric conditions in terms of change in the concentration of air pollutants. We have measured the cosmic ray flux before and after the lockdown to observe the apparent change if any due to change in the atmospheric conditions. In this article, we report the measured cosmic ray flux at Kolkata (22.58$^{\circ}$N 88.42$^{\circ}$E and 11~m Above Sea Level) along with the major air pollutants present in the atmosphere before and after the lockdown.