Effect of relative humidity on the electrical conductivity of marine air

Abstract

Measurements of the atmospheric electric conductivity made in the equatorial Indian Ocean and Arabian Sea in August and September 1991 show that the value of conductivity decreases from 2.3 × 10^-14 mho m^-1 in the equatorial Indian Ocean, where relative humidity of the surface air is 70-80%, to 1.1 × 10^-14 mho m^-1 in the region of the Somali current, where relative humidity of the surface air increases to 80-90%. the inverse relationship observed between conductivity and relative humidity, in spite of showing a large scatter, is stronger in the case of negative than positive conductivity. the sharp increase in the sizes of ions and marine aerosol particles when the relative humidity exceeds 75-80% is proposed as the cause of the observed decrease in conductivity in the region of the Somali current.