Satellite imagery

Satellite images are nowadays routinely used in weather forecasting, both visually and as input information for the weather models. Part of the information directly describes the state of the atmosphere such as: cloud cover, water vapour, aerosols (such as volcanic ash), trace gases, as well as wind speed and direction. Another important part of the information characterizes the surface conditions of the globe, both land and ocean such as: surface temperature, surface albedo, snow cover, glaciers, sea ice, wave height, pollution of water (such as oil spills), soil moisture, biomass, leaf area index, fires etc.

FMI participates in the Satellite Application Facility projects CM-SAF and H-SAF financially supported by EUMETSAT (the European Organisation for the Exploitation of Meteorological Satellites). CM-SAF concentrates on climate and H-SAF on hydrology.

In CM-SAF, FMI is responsible for developing the global surface albedo product for polar orbiting satellites carrying the AVHRR instrument, which has a long history. In H-SAF, FMI develops snow cover products for meteorological and hydrological purposes. The meteorological snow cover product is daily and operationally available for the SEVIRI instrument of the geostationary satellite MSG. The corresponding snow product for the polar orbiting satellite METOP carrying the AVHRR instrument is pre-operational.

The Arctic surface albedo in August 1982 (left) and in August 2009 (right). The brightest area is Greenland (about 0.8) and the darkest area is open water (about 0.06). Sea ice albedo varies between these extremes. The white area at the centre of the image is not covered by the satellite used for albedo retrieval.