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Charge transfer accompanying the splashing of supercooled raindrops on hailstones
Author(s) -
Latham J.,
Warwicker R.
Publication year - 1980
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49710644912
Subject(s) - supercooling , drop (telecommunication) , electric field , thunderstorm , materials science , mechanics , meteorology , environmental science , physics , quantum mechanics , computer science , telecommunications
Measurements have been made of the charge transfer accompanying the splashing of a supercooled water drop, of raindrop dimensions, onto a simulated hailstone. The important variables were: temperature of drop and hailstone (–4°C to –20°C); impact velocity (1 to 4ms −1 ); impact parameter (0 to ±1); drop composition (pure water; NaCl and (NH 4 ) 2 CO 3 solution; CO 2 ‐saturated water; water containing detergent); and surface structure of the hailstone. It was found that the hailstone always acquired a positive charge, of magnitude invariably less than 200 fC, and usually around 20 fC. These values are much less than those measured by other workers (in experiments where the drops were not significantly supercooled), and are far too small to be of significance in thunderstorm electrification. When these experiments were performed in the presence of an electric field substantial charges (up to 300 fC m V −1 ) were measured, but their sign was such as to dissipate the field.