TY - JOUR A1 - Wei, M. A1 - De Pondeca, M. S. F. V. A1 - Toth, Z. A1 - Parrish, D. T1 - Estimation and calibration of observation impact signals using the Lanczos method in NOAA/NCEP data assimilation system JO - Nonlin. Processes Geophys. J1 - NPG VL - 19 IS - 5 SP - 541 EP - 557 Y1 - 2012/09/25 PB - Copernicus Publications SN - 1607-7946 UR - https://npg.copernicus.org/articles/19/541/2012/ L1 - https://npg.copernicus.org/articles/19/541/2012/npg-19-541-2012.pdf DO - 10.5194/npg-19-541-2012 ER -