Study of radon and its progeny concentrations and its effect on atmospheric conductivity

In this paper, we have reported ionization rate calculated from the Radon and its progeny is closely representing the derived ionization rate from Ion-Aerosol Equilibrium equation. We derived the concentration of small ions from the ionization rate from radon and its progeny and results shows good agreement of the concentration of small ions from direct measurement from NAIS (Neutral Air ion Spectrometer). The ionization rate at this tropical station shows minima in the afternoon and maxima in the early morning. Also examined the variation of ionization rate with the meteorological parameter. At lower layers of the atmosphere, ionization is mainly due to the radiations emitted by radon and its decay products. Short-lived daughters of radon (²¹⁸Po, ²¹⁴Pb, ²¹⁴Bi and ²¹⁴Po) are electrically charged and are chemically reactive. So we have calculated the conductivity of the atmosphere. The observed conductivity shows a maximum values in small ions. A mean ± Standard deviation value of Conductivity varies 2.90 ± 1.73, 4.77 ± 1.58, 2.93 ± 1.50, 8.54 ± 3.23, 6:19 ± 2.72 for small, big cluster, and intermediate, light large and heavy large ions respectively. The conductivity varies from 1.23 x 10^-9 to 8.50 x 10^-9 for small ions, 2.59 x 10^-10 to 8.36 x 10^-10 for big clusters ions, 1.46 x 10^-10 to 7.52 x 10^-10 for intermediate ions, 4.68 x 10^-11 to 1.91 x 10^-11 for light large ions, 6.20 x 10^-11 to 1.36 x 10^-10 per ohm per meter. (author)