MSG cloud products - final report

With the launch of Meteosat Second Generation (MSG) a new era of European geo-stationary meteorological satellites started in 2002. The Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard MSG scans the Earth every 15 minutes with 10 narrow spectral channels. This is a huge improvement over the current generation of METEOSAT satellites that was developed in the 1970s and measures in 3 broad spectral bands. SEVIRI data may be used for developing a whole new range of products for industries that have an interest in atmospheric processes and surface properties. Especially in operational meteorology, MSG is a large step forward. The purpose of the “MSG cloud products” project was to prepare the KNMI processing environment for MSG measurements and to create an interface between the research departments (Climate and Seismology and Weather and Models) and daily operational meteorology. The project aims to communicate new developments to the operational meteorologists and also to obtain user requirements from the meteorologists to be used in research.

For data processing we used a prototype processing environment, KNMI Local implementation of APOLLO retrievals in an Operational System (KLAROS). This environment was designed to generate and display cloud properties products such as top temperature, optical thickness, and liquid water content. Because MSG was not launched during the cause of this project, the cloud products were generated from NOAA-AVHRR data. To present the prototype products a special infrastructure was set up for the MetOffice of KNMI. The researchers consulted the operational meteorologists to assess the usefulness of the products for weather prediction. During the course of the project the meteorologists became familiar with the cloud property products, made suggestions for product improvement, and brought up ideas for new products. These products are expected to contribute to higher quality forecasts. Some suggestions could be implemented directly, while the ideas for new products required more research. We found that products of particular interest for the meteorologists are those, which define the amount of sunlight reaching the ground in cloudy conditions (optical thickness) and those, which describe the geometrical vertical extent of clouds (and thus the cloud top and base height). The first is directly related to the dispersal rate of fog, exposure to UV-B (skin cancer) and crop yield. The results of the consultations will be presented in this report.

The project had length of only 9 months, but it established a valuable link between operational meteorology and research departments. The meteorologists recognized the added value to the MSG cloud products and their importance for daily weather forecasting. However, it was indicated that the visualization tools from the research department were not well suited for use by meteorologists. It took the meteorologists too much time to familiarize with them. It may be concluded that further modifications of the software architecture are needed before the modules for operational processing of MSG data can be implemented. This would greatly improve the quality and efficiency of testing new quantitative cloud products in operational meteorology. In that sense this project is ongoing and will continue until and after the launch of MSG.