The capacitance of solid and hollow hexagonal ice columns

The capacitances of solid and hollow hexagonal ice columns are calculated using the classical electrostatic analogy theory. Finite element techniques are used to solve the Laplace equation to obtain water vapor density distribution from which the capacitance can be determined. The results show that solid and hollow columns of the same dimensions have nearly the same capacitance despite the existence of cavities in the latter, which implies the same mass growth rates of the two. The computed capacitances agree well with experimental measurements. Since the volume of a hollow column is smaller than that of a solid column of the same dimensions, the same mass growth rate prompts the hollow column to grow faster in linear dimensions and hence interact stronger with radiation. This will have important implications on the cirrus influence on climate.