TY - GEN AU - Rabier, F. AU - Andersson, E. AU - AU - TI - The ECMWF implementation of three dimensional variational assimilation (3D-Var) T2 - ECMWF Technical Memorandum VL - 242 PY - 1997/// CY - Reading PB - ECMWF KW - PREVISAO NUMÉRICA KW - IM ER -