Weather satellites play a key role in meteorology. They show meteorological processes in the atmosphere around the clock. MeteoSwiss obtains the satellite data from EUMETSAT, a consortium of European countries which together operate METEOSAT and other Earth observation satellites.
Satellite observations are of central importance for the creation of weather forecasts. Geostationary satellites provide an accurate picture of weather activity for very large areas of the Earth and do so practically in real time. The weather satellites transmit their data every couple of minutes, allowing for changes in the atmosphere to be tracked continuously. Satellite meteorology is also increasing in significance worldwide for the observance of climate variables.
Among other sources, MeteoSwiss obtains data from the METEOSAT Second Generation (MSG) satellite. This geostationary Earth observation satellite is operated by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). The satellite delivers images in 12 spectral channels of different wavelengths. The satellite's field of vision is restricted to what it can see from its fixed position at an altitude of 36,000 kilometres above the intersection of the equator and the Greenwich Meridian. From this position, METEOSAT covers almost half of the globe. The satellite provides high-resolution, digital images at intervals of 5-10 minutes. These are processed initially by the control centre in Darmstadt (Germany) and then distributed to the recipients. Following further processing, MeteoSwiss distributes the data to its various customers including weather forecasting services, climate researchers and the media.
METEOSAT spectral channels
The data transmitted from weather satellites is usually displayed in the form of images. The METEOSAT Second Generation satellite models possess 12 infrared and visible channels. This not only allows them to represent clouds and their different layers, but also to depict the transportation of sand from the Sahara Desert or ash clouds from volcanoes through the combination of various channels.
Every three hours, MeteoSwiss provides current satellite images of cloud cover free of charge under "Measurement values". Updated images can be obtained under "Services & publications" every 15 minutes subject to a fee.