Cb-TRAM: Tracking and monitoring severe convection from onset over rapid development to mature phase using multi-channel Meteosat-8 SEVIRI data

摘要

Cb-TRAM is a new fully automated tracking and nowcasting algorithm. Intense convective cells are detected, tracked and discriminated with respect to onset, rapid development, and mature phase. The detection is based on Meteosat-8 SEVIRI (Spinning Enhanced Visible and Infra-Red Imager) data from the broad band high resolution visible, infra-red 6.2 µm (water vapour), and the infra-red 10.8 µm channels. In addition, tropopause temperature data from ECMWF operational model analyses is utilised as an adaptive detection criterion. The tracking is based on geographical overlap between current detections and first guess patterns of cells predicted from preceeding time steps. The first guess patterns as well as short range forecast extrapolations are obtained with the aid of a new image matching algorithm providing complete fields of approximate differential cloud motion. Based on these motion vector fields interpolation and extrapolation of satellite data are obtained which allow to generate synthetic intermediate data fields between two known fields as well as nowcasts of motion and development of detected areas. Examples of the application of Cb-TRAM and a comparison to precipitation radar and lightning data as independent data sources demonstrate the capabilities of the new technique.