THE THEORY OF HAILSTONE GROWTH

R. G. Zakinyan

An attempt is made to combine the available theories on hailstone growth. The Schumann—Ludlam, Kachurin, and Zhekamukhov theories are analyzed for that purpose. A notion of critical water content which determined the transition from dry conditions of hailstone growth to its moist conditions is introduced into the Schumann—Ludlam theory. The film regime itself in moist conditions is not studied. The Kachurin theory studies the liquid film motion. A notion of a balanced film thickness is introduced. It determines the transition from dry conditions of hailstone growth to its moist conditions. Two approaches are independent. Zhekamukhov made the next step in the development of the theory of hailstone growth. In his theory the conditions of liquid film growth are studied at the hailstone surface. This shows that the thickness of liquid film increases with time if the cloud water content exceeds critical water content by Schumann—Ludlam.