Abstract
A positive electric charge separates on ice irrespective of the chemical impurities found in liquid water when the liquid water is removed from the ice surface at temperatures warmer than -10°C. This mechanism can be explained in relation to the formation of an electric charge double-layer at the boundary between water and ice. This phenomenon helps to explain the positive electrification of rime when it collides with ice crystals in clouds with warm temperatures and large cloud water contents.
A special electric current is measured when liquid water moves over an ice surface. This phenomenon could affect the charge separation in thundercloud when large, supercooled drops collide with hail.
