Open AccessCharge transfer between colliding hydrometeors: Role of surface tension gradients
Author(s) -
Graciaa A.,
Creux P.,
Lachaise J.,
Schechter R. S.
Publication year - 2001
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2001jd900015
Subject(s) - surface tension , mechanics , charge (physics) , flow (mathematics) , tension (geology) , materials science , chemical physics , physics , thermodynamics , composite material , quantum mechanics , ultimate tensile strength
A mechanism is postulated to account for the exchange of electrical charge that has been observed to take place when hydrometeors in a “cloud” created in the laboratory collide. A hydrodynamic flow induced by variation of the surface tension at an air/water interface is regarded as the main driving force. This flow created by forces acting within an interfacial region will transport the excess negative charge that normally resides at an air/water interface from one interfacial region to another, thereby yielding a separation of charge. An estimate of the quantity of charge exchanged by this process, using reasonable parametric values, is in accord with laboratory observations. In some interactions our proposed mechanism is only valid if a stable thick water film coats the surface of one of the colliding hydrometeors. Measurements are presented to show that the ice/water interface is negative, and this is a condition needed to confer stability of thick water films on ice.