The study of the formation of a hailstone by means of isotopic analysis

The deuterium-hydrogen ratio of the water at various levels in a cloud can be computed from the pressure, the temperature, and the mean D/H ratio of the cloud, assuming that the condensed phase is in equilibrium with the vapor phase. A hailstone has been collected and the D/H ratio of the successive layers has been determined. From these values and the knowledge of the vertical structure of the atmosphere during the shower, the life history of the hailstone can be traced. The results of the isotopic analysis have also been compared with the photographic analysis of other hailstones collected from the same shower. A further exploration of the isotopic technique for the investigation of hail may lead to other important conclusions.