Instructions for interpreting satellite images
Cloud animations have been produced at the Finnish Meteorological Institute using measurements from the EUMETSAT Meteosat satellite. The satellite is located above the equator at an altitude of approximately 36 000 km.
The satellite images show high and cold clouds as white. The lower clouds appear in different shades of grey.
The satellite images for daylight are a combination of reflected sunlight measurements. In addition to clouds, sunlight also reflects from vegetation and from ground and water surfaces. During the daytime, the pictures also show the greenery of vegetation during the growing season. In winter, snow and ice appear as white, making the clouds less visible.
At night, the image shows the level of infra-red radiation in grey. When the sun is shining at a low level, such as in the morning and in winter, the images may be overexposed in some places.