TY - CPAPER AU - Jean-Noël Thépaut BT - ECMWF/Geo Workshop on Atmospheric Reanalyis, 19-22 June 2006 CY - Shinfield Park, Reading DA - 2006 LA - eng PB - ECMWF PP - Shinfield Park, Reading PY - 2006 SP - 107 EP - 112 T2 - ECMWF/Geo Workshop on Atmospheric Reanalyis, 19-22 June 2006 TI - Assimilating only surface-pressure observations in 3D and 4D-Var ER -