Retrieval of High Ice Water Content from MSG-SEVIRI: updated algorithm and pre-operational application (HAIC D32.2)

Geostationary imagers provide a possibly valuable means to monitor situations with high ice water content (high IWC), because they cover large spatial domains with a high temporal repeat frequency. However, passive visible/infrared (VIS/IR) imagers – unlike active sensors – do not provide much vertical context, which may limit their utility for the purpose of detecting high IWC values. This report describes a detailed evaluation of - and improvements to - a previously within the HAIC project developed High Ice Water Content mask for the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument on board the Meteosat Second Generation (MSG) satellites. The evaluation consists of a detailed comparison with measurements of active remote sensing satellites (radar/lidar), and includes the calculation of verification statistics, which are used to define an improved High IWC mask. Limitations of the improved High IWC mask are also discussed, and finally the implementation of the improved High IWC mask in the KNMI operational data stream and near-real time visualization tool on the MSG-CPP web portal is presented. This implementation was done in support of the 2015 HAIC Cayenne measurement campaign. Measurements of this campaign will be used for further future evaluation of the High IWC mask.