The determination of snow albedo using combined AATSR and MERIS observations
Alexander Kokhanovsky(1) and Mathias Schreier(1)
(1) University of Bremen, O. Hahn Allee 1, 28213 Bremen, Germany
The snow and ice fields along with clouds are major reflectors of the solar radiation back to the outer space. It was found that the ice extent is considerably reduced in recent decades. This can lead to the less reflective planet and also to the enhanced global warming. Not only the extent of ice and snow but also reflective properties of these media (e.g., albedo) influence the reflective power. Therefore, it is of importance to study the temporal changes and long term trends in snow and ice properties from a satellite.
In this work we use combined measurements of MERIS and AATSR to retrieve the snow albedo in Spitsbergen. AATSR data are mostly used for the cloud screening and for the separation of cloud and snow (e.g., using 3.7micrometer measurements). Then the snow albedo is retrieved using MERIS measurements in the spectral range 412-865nm. The absorption of ozone is accounted for using simultaneous SCIAMACHY observations. Also the effective grain size is retrieved using near IR top-of-atmosphere reflectance measurements over extended snow fields.
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,