World MER RR

Description:

This global composite is made up of true colour images using three bands 3, 5 and 7 of the 15 spectral bands MERIS measures, with data combined from around 500 separate orbits, which were chosen in order to obtain cloud-free images. The full image has a 1.2 km resolution and is made up of 40,000 by 20,000 pixels, equal to 2.5 gigabytes of output data.

MERIS records surface reflectivity, and a wide variety of land surface coverings can be discerned in this way, from ice to forest, grassland to desert. Throughout the month of March, when the acquisitions for this composite were collected, much of the northern hemisphere remains covered in snow and ice, with snows extending far down across Russia. Comparatively small geographical features can be clearly made out, such as the increasingly desiccated Aral Sea in the lowlands of Central Asia, positioned east of the Caspian Sea.

In addition MERIS shows how the Earth's oceans vary in colour almost as much as the land. Particularly noticeable is the effect of the Gulf Stream around the British Isles with greenish sediment and phytoplankton seeming to flare off the coast, the distinctive water colour in the shallows of the Bahamas, and the coral reefs off Australia. Artefacts of Envisat's orbital passes can also be detected around the equatorial ocean areas of the image, caused by the sun glinting off the sea surface.

The image was originally prepared by GAEL Consultant of France and shown for the first time at the ESA stand at the 2003 Paris Air Show at Le Bourget.

Technical Information:

• Instrument: MEdium Resolution Imaging Spectrometer (MERIS)
• Date of Acquisition: 1 March-31 March 2003
• Orbit number: 05224-05667
• Instrument features: Reduced Resolution
• Resolution: 1200-metres
• Coordinates:

Download high resolution tif here (28886 Kbytes)

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry