TY - GEN AU - Florence Rabier AU - H Järvinen AU - E. Klinker AU - J.-F. Mahfouf AU - Adrian Simmons BT - ECMWF Technical Memoranda CY - Shinfield Park, Reading DA - 02/1999 DO - 10.21957/1yb0ok68e LA - eng M1 - 271 PB - ECMWF PP - Shinfield Park, Reading PY - 1999 EP - 26 T2 - ECMWF Technical Memoranda TI - The ECMWF operational implementation of four dimensional variational assimilation. Part I: Experimental results with simplified physics UR - https://www.ecmwf.int/node/11794 ER -