Seasonal variations in 7Be activity in air from 2001 to 2020 at Rawatbhata, Chittorgarh District, Rajasthan (India)

This article presents the results of seasonal variation in 7 Be activity in air, measured over the last two decades (2001–2020) in air particulate samples from Rawatbhata in the Chittorgarh district of Rajasthan, India, in the Northern Hemisphere. The activity of 7 Be was measured using the nondestructive technique of gamma-ray spectrometry with an high purity germanium detector (400 cc) with 110% relative efficiency. Analysis of measured activity reveals that 7 Be activity decreased from 2001 to 2004, then slightly increased until 2020 due to fluctuations in solar activity and meteorological parameters. The mean value of measured 7 Be activity is 50%, 67%, and 22% higher in the spring, summer, and winter seasons in comparison to the rainy season, while it is 23% and 36% higher in spring and summer as compared to the winter season in the last two decades. The trend of seasonal variation of 7 Be in the air is summer > spring > winter > rainy. The 7 Be activity variation is insignificantly correlated with meteorological parameters of atmospheric pressure, temperature, and relative humidity, although this is not conclusive because this relation also depends on other associated endemic meteorological and suspended particulate matter (SPM), which affect the distribution and migration of 7 Be. The results for 7 Be activity in particulate matter were positively correlated with temperature variations and SPM.