Radon and its short-lived progeny: variations near the ground

Abstract

In the atmosphere above the surface of the Earth the concentrations of radon and its progeny are measured, along with the meteorological parameters from December 1997 to December 2000 for a continental location, Pune (18°N,74°E), India. The concentrations show maxima in the early morning hours when the turbulence mixing is minimum; whereas in the afternoon the turbulence mixing is maximum and concentrations exhibit minima. The median values of concentration are 9.70 and 2.84 Bqm^-3, respectively, for radon and its progeny, during the observation period. Ionization rates in the atmosphere are derived for the same period. It is found that the ionization rate exhibits a median value of 5.48 ion pairs cm^-3 s^-1. The diurnal and seasonal variations in the concentrations of radon and its progeny, and the ionization rate due to radioactivity are found to exhibit correlation with the relative humidity, and anti-correlation with the temperature.