ON THE SEARCH FOR A REPRESENTATIVE DRAG COEFFICIENT LAW TO BE USED INHAIL TRAJECTORY SIMULATIONS

A new method to calculate the ice particle drag coefficient used in ha ilstone trajectory calculations is presented. The method takes into ac count the high variability of this parameter and also allows for the i nvestigation of the different trajectories that equally initialized em bryos may follow within a cloud due to non-deterministic changes in th eir surface texture. The method is applied in a hail trajectory simula tion model. The results are compared with those obtained by means of c urves fitted to the drag coefficient going through mean, low and high values. The aim of this work is to investigate the representativity of hail trajectories simulated using these curves for the assessment of the drag coefficient value. (C) 1998 Elsevier Science B.V. All rights reserved.