Two Approaches for an Icing Climatology Over Europe : Surface Freezing Precipitations and Altitude Icing Areas Based on the SIGMA System

Two approaches have been attempted to establish an icing climatology over Europe.

Firstly, a climatology has been established by using the results of SIGMA (Severe Icing Geographic identification in Meteorology for Aviation). The situations calculated by SIGMA during two winters have been studied. Secondly, a climatology of the occurrence of freezing precipitations at ground level has been established. It is based on reports of freezing precipitation in SYNOP messages from the winters covering the years 1995 to 1998. The geographical domain covered is Western and Central Europe. The frequency of occurrence of freezing precipitations (freezing rain, freezing drizzle and ice pellets) and freezing fog was computed. The results of these two climatologies show that north eastern Europe is more prone to icing phenomena.