Anderson , J. L. 2003 . A local least squares framework for ensemble filtering . Mon. Wea. Rev . 131 , 634 – 642 .
Anderson , J. L. 2007 . Exploring the need for localisation in ensemble data assimilation using a hierarchical ensemble filter . Physica D 230 , 99 – 111 .
Anderson , J. L. , Wyman , B. , Zhang , S. and Hoar , T. 2005 . Assimilation of surface pressure observations using an ensemble filter in an idealised global atmospheric prediction system. J. Atmos. Sci. 62 , 2925 - 2938.
Bishop , C. H. , Etherton , B. J. and Majumdar , S. 2001 . Adaptive sampling with the ensemble transform Kalman filter. Part 1: theoretical aspects . Mon. Wea. Rev . 129 , 420 – 436 .
Bishop , C. H. , Reynolds , C. A. and Tippett , M. K. 2003 . Optimisation of the fixed global observing network in a simple model . J. Atmos. Sci . 60 , 1471 – 1489 .
Burgers , G. , van Leeuwen , P. J. and Evensen , G. 1998 . Analysis scheme in the ensemble Kalman filter . Mon. Wea. Rev . 126 , 1719 – 1724 .
Cohn , S. E. 1997 . An introduction to estimation theory . JMeteoro/. Soc. Jpn . 75 , 257 – 288 .
Cohn , S. E. , Sivakumaran , N. S. and Todling , R. 1994 . A fixed-lag Kalman smoother for retrospective data assimilation . Mon. Wea. Rev . 122 , 2838 – 2867 .
Daley , R. 1991 . Atmospheric Data Analysis . Vol. 2. Cambridge Univer-sity Press , New York , 457 pp .
Evensen , G. 1994 . Sequential data assimilation with a nonlinear quasi-geostrophic model using Monte Carlo methods to forecast error statis-tics . J. Geophys. Res . 99 , 10143 – 10162 .
Evensen , G. and van Leeuwen , P. J. 2000 . An ensemble Kalman smoother for nonlinear dynamics . Mon. Wea. Rev . 128 , 1852 – 1867 .
Evensen , G. 2003 . The ensemble Kalman filter: theoretical formulation and practical implementation . Ocean Dyn . 53 , 343 – 367 .
Gaspari , G. and Cohn , S. E. 1999 . Construction of correlation functions in two and three dimensions , J. R. MeteoroL Soc . 125 , 723 – 757 .
Hamill , T. M. and Snyder , C. 2001 . Using improved background error covariances from an ensemble Kalman filter for adaptive observations . Mon. Wea. Rev . 130 , 1552 – 1572 .
Held , I. and Suarez , M. J. 1994 . A proposal for the intercomparison of the dynamical cores of atmospheric general circulation models . Bull. Am. Meteorol. Soc . 75 , 1825– 1830 .
Houtekamer , P. L. and Mitchell , H. L. 1998 . Data assimilation using an ensemble Kalman filter technique . Mon. Wea. Rev . 126 , 796 – 811 .
Houtekamer , P. L. and Mitchell , H. L. 2005 . Atmospheric data assimi-lation with an ensemble Kalman filter: results with real observations . Mon. Wea. Rev . 133 , 604 – 620 .
Jazwinski , A. H. 1970 . Stochastic Processes and Filtering Theory . Aca-demic Press , San Diego , 376 pp .
Kalman , R. E. 1960 . A new approach to linear filtering and prediction problems . Trans. AMSE Ser D. J. Basic. Eng . 82 , 35 – 45 .
Kalnay , E. , Kanamitsu , M. , Kistler , R. , Collins , W. , Deaven , D. and co-authors , 1996. The NCEP/NCAR reanalysis project. Bull. Am. Mete-oroL Soc . 77 , 437 - 471 .
Khare , S. P. 2004 . Observing Network Design for Improved Prediction of Geophysical Fluid Flows-Analysis of Ensemble Methods . PhD thesis , Princeton University , 195 pp .
Khare , S. P. and Anderson , J. L. 2006a . An examination of ensemble filter based adaptive observation methodologies . Tellus 58A , 179 - 195 .
Khare , S. P. and Anderson , J. L. 2006b . A methodology for fixed obser-vational network design: theory and application to a simulated global prediction system . Tellus 58A , 523 – 537 .
Lorenz , E. N. and Emanuel , K. A. 1998 . Optimal sites for supplementary weather observations: simulation with a small model , J. Atmos. Sci . 55 , 399 – 414 .
Lorenz , E. N. 1996 . Predictability: a problem partly solve. Proceedings of the Seminar on Predictability Volume 1, ECMWF, Reading, Berk-shire, UK, pp. 1 - 18 .
Simmons , A. J. and Burridge , D. M. 1981 . An energy and angular-momentum conserving vertical finite-difference scheme and hybrid vertical coordinates . Mon. Wea. Rev . 109 , 758 – 766 .
Simmons , A. J. and Gibson , J. K. 2000 . ERA-40 Project report series no. 1. The ERA-40 project plan, ECMWF, Reading, UK.
Snyder , C. and Zhang , E 2003 . Assimilation of simulated doppler radar observations with an ensemble Kalman filter . Mon. Wea. Rev . 131 , 1663 – 1667 .
Tippett , M. K. , Anderson , J. L. , Bishop , C. H. , Hamill , T. M. and Whitaker , J. S. 2003 . Ensemble square-root filters. Mon. Wea. Rev . 131 , 1485 - 1490 .
Whitaker , J. S. and Compo , G. P. 2002 . An ensemble Kalman smoother for reanalysis. Proc. Symp. on Observations, Data Assimilation and Probabilistic Prediction , Orlando, FL , Amer. Meteor. Soc. , 144 - 147 .
Whitaker , J. S. and Hamill , T. M. 2002 . Ensemble data assimilation without perturbed observations . Mon. Wea. Rev . 130 , 1931 – 1924 .