Water Shells on Ice Pellets and Hailstones

Abstract

A numerical model has been developed to investigate water films or shells on ice pellets and hailstones with radii from 0.1 to 0.5 cm. The model considers a hydrometeor consisting of a rigid, spherical ice core of density 0.9 gm cm?3 surrounded by a shell or film of water. The water volume of the hydrometeor is assumed to be conserved. A set of deformation equations for the water film is constructed from a series expansion of an equation which is based on the balance of pressures acting on the hydrometeor. The results indicate that an ice pellet or hailstone with radius <0.45 cm can have a water film more or less evenly distributed over the ice core; for a hailstone >0.45 cm radius a rather unrealistic water distribution is obtained from the present model.