Mária Putsay, Zsófia Kocsis, Gergely Bölöni, Mihály Szűcs (Hungarian Meteorological Service) and Marianne König (EUMETSAT) have performed a study of the Impact of Background Models to the Global Instability Index product. Here you can download a presentation of the study.

The Global Instability Indices product provide information on the pre-convective environment: precipitable water content (total column and three distinct layers) and instability indices, in clear sky conditions.

It is derived by a physical retrieval using 6 SEVIRI infrared channels. The physical retrieval tries to find an atmospheric profile which best reproduces the observations. This is a multi-solution problem, and a “background profile” is used as a constraint.

Different NWP models (ECMWF, ALADIN/HU, AROME) were used as a background for several cases to study the impact of the background fields. Cases when the models had similar and different forecasts were selected then the GII outputs were compared to each other. The effects of the horizontal and vertical resolution of the background fields were studied.