A strategy for operational implementation of 4D‐Var, using an incremental approach

Quarterly Journal of the Royal Meteorological Society - Tập 120 Số 519 - Trang 1367-1387 - 1994
Philippe Courtier1, Jean‐Noël Thépaut1, A. Hollingsworth1
1European Centre for Medium‐Range Weather Forecasts, UK

Tóm tắt

AbstractAn order of magnitude reduction in the cost of four‐dimensional variational assimilation (4D‐Var) is required before operational implementation is possible. Preconditioning is considered and, although it offers a significant reduction in cost, it seems that it is unlikely to provide a reduction as large as an order of magnitude. An approximation to 4D‐Var, namely the incremental approach, is then considered and is shown to produce the same result at the end of the assimilation window as an extended Kalman filter in which no approximations are made in the assimilating model but in which instead a simplified evolution of the forecast error is introduced. This approach provides the flexibility for a cost—benefit trade‐off of 4D‐Var to be made.

Từ khóa


Tài liệu tham khảo

10.1017/CBO9780511569647

10.1002/qj.49712051707

Cohn S. E.1992Short‐term dynamics of forecast error covariances. Pp.157–170in Proc. ECMWF workshop on variational assimilation with special emphasis on three‐dimensional aspects 9–12 November 1992 Reading UK

10.1175/1520-0493(1991)119<1757:TBOFEC>2.0.CO;2

Courtier P.1987‘Application du contrǒle optimal à la prévision numérique en météorologie’. Thèse de doctorat de l'université Paris VI

Courtier P.1991‘Two difficulties encountered in the validation of cycle 7’. Note ARPEGE No. 24 (available from METEO‐FRANCE)

10.1034/j.1600-0870.1990.t01-4-00004.x

Courtier P. Thépaut J.‐N.andHollingsworth A.1992A strategy for operational implementation of 4D‐Var. Pp.437–464in Proc. 1992 ECMWF workshop on variational assimilation with special emphasis on three‐dimensional aspects 9–12 November 1992 Reading UK

Courtier P. Andersson E. Heckley W. Kelly G. Pailleux J. Rabier F. Thépaut J.‐N. Undén P. Vasiljevic D. Cardinali C. Eyre J. Hamrud M. Haseler J. Hollingsworth A. McNally A.andStoffelen A.1993Variational assimilation at ECMWF. ECMWF Tech. Memo 194 (available from ECMWF)

Daley R., 1991, Atmospheric data analysis

Davidon W. C.1959‘Variable metric for minimization’. Report ANL‐5990 Argonne National Laboratory Argonne Illinois

10.1002/qj.49711749806

10.1175/1520-0493(1989)117<2437:AVCAT>2.0.CO;2

10.1090/S0002-9939-1955-0069585-4

10.1034/j.1600-0870.1992.00002.x

10.1175/1520-0493(1993)121<1803:AOSWLD>2.0.CO;2

Ghil M., 1981, Dynamic Meteorology: Data assimilation method

10.1007/BF01589113

Gill P. E., 1981, Practical optimization

10.1137/1031003

Heckley W. A. Courtier P. Pailleux J.andAndersson E.1992On the use of background information in the variational analysis at ECMWF. Proc. ECMWF workshop on variational assimilation with emphasis on 3D aspects. 9–12 November 1992 Reading UK

10.6028/jres.049.044

10.1016/S0076-5392(09)60368-4

10.1111/j.1600-0870.1988.tb00408.x

10.1111/j.1600-0870.1986.tb00459.x

Lönnberg P.1988Developments in the ECMWF analysis system. Pp.75–119in Proc. 1988 ECMWF seminar on data assimilation and the use of satellite data Reading UK

10.1002/qj.49711247414

10.1002/qj.49711447911

10.1175/1520-0493(1987)115<1479:CGMFLS>2.0.CO;2

10.1175/1520-0493(1992)120<1433:VDAWAA>2.0.CO;2

10.1175/1520-0493(1992)120<1747:TNMCSS>2.0.CO;2

10.1111/j.1600-0870.1986.tb00418.x

10.1002/qj.49711850604

10.1002/qj.49711951213

10.1034/j.1600-0870.1993.00016.x

Talagrand O.1988Four‐dimensional variational assimilation. Proc. 1988 ECMWF seminar on data assimilation and the use of satellite data Reading UK

10.1002/qj.49711750206

10.1002/qj.49711649609

10.1175/1520-0493(1993)121<3393:IODAOI>2.0.CO;2

10.1256/smsqj.50906

10.1175/1520-0493(1991)119<1602:NALEOI>2.0.CO;2

Wergen W., 1992, The effect of model errors in variational assimilation, Tellus, 44, 297, 10.3402/tellusa.v44i4.14962

10.1093/biomet/39.1-2.1

Zou X., 1993, Variational data assimilation with moist threshold processes using NMC spectral model, Tellus, 45, 370, 10.3402/tellusa.v45i5.14900

10.1034/j.1600-0870.1993.00013.x

10.1175/1520-0493(1993)121<2396:RFDVDA>2.0.CO;2

Zupanski M., 1993, A preconditioning algorithm for large‐scale minimization problems, Tellus, 45, 478, 10.3402/tellusa.v45i5.15048