General Heat and Mass Exchange of Spherical Hailstones

Abstract

By setting up and solving general equations for the heat balance and the material transfer between a spherical hailstone and its environment it is possible to show how the different variables such as air temperature, air pressure, liquid water content of the air (in the form of drops), hailstone diameter, speed of fall of the hailstone, its surface temperature and growth rate are interdependent. At the same time growth zones can he delimited within which accretion is accompanied by evaporation or sublimation of H₂0, or where an increase of mass by sublimation exceeds the amount of accretion. From the growth conditions it is possible to classify the resulting ice deposits on a physical basis.