|Title||Evaluation of the impact of the space component of the Global Observing System through Observing System Experiments.|
|Series/Collection||Final Report SOW EUM.MET.SOW.04.0290|
|Authors||Kelly, GA, Thépaut, J-N|
|Event Series/Collection||EUMETSAT/ECMWF Fellowship Programme Research Reports|
|Place of publication||Shinfield Park, Reading|
As many more satellite instruments (both active and passive) became operational the challenge was, and still is, how to assimilate these space measurements together with all the conventional measurements. Since 2001 the number of satellite sensors being used has increased by a factor of four and now is in excess of forty sensors. A study, sponsored by EUMETSAT, has been carried out to evaluate the impact of the space component of the Global Observing System through Observing System Experiments. In this study the relative contributions of the various space observing systems have been assessed within the context of the ECMWF data assimilation system. It is found that all the space based sensors generally contribute in a positive way to the overall improvement of the ECMWF forecast system.