Comparisons of Raindrop Size Distributions Measured by an Optical Disdrometer and Electrically Charged Raindrops

Abstract

Raindrop size distributions observed with a particle size velocity disdrometer are contrasted with respect to the size distributions of charged raindrops obtained with a special device designed to determine the size and electric charge of raindrops. The measurements were performed for three thunderstorms occurred in the vicinity of Córdoba, Argentina during RELAMPAGO campaign. In general, the results show that more than 66% of the raindrops measured with the optical disdrometer have diameters <1 mm and more than 90% of the charged raindrops have diameters >1 mm. A systematic difference between both raindrops size distributions was observed, which remains during the whole evolution of the storms. Under the hypothesis that the electrically charged raindrops were melted ice hydrometeors, we analyze if the larger raindrops recorded by the disdrometer during these storms may also have been melted ice particles.