Charge separation in updraft of convective regions of thunderstorm

Abstract

The experiments described in this work are concerned with ice-crystal graupel interactions. The influence of the impact velocity on charge separation during collisions is analyzed for three different velocities: 6, 8 and 11 m s-1. The ambient temperature was varied in the range -5 to -30°C and the effective water content between 0 to 2 g m-3. Charge diagrams of the sign of the electric current on the graupel as a function of the ambient temperature and the effective liquid water content for each velocity are presented. The results indicate that increasing the velocity leads to negative particle charging during riming at higher velocity and the implication of these findings to non-severe thunderstorm are discussed. Copyright 2006 by the American Geophysical Union.