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ALADIN documentation / 3DVAR aspects, 2007 updated

November 2002

This note gives a detailed description of the algorithmic part, for the benefit of phasing, remote installations and development. A theoretical overview is recalled for completeness with the technical section. A "User’s guide" is added for the general users of 3dvar.

  • Formalism of incremental variational analysis
    • 3dvar
    • Background error covariance matrix B
    • Preconditioning
    • 4dvar
  • Data flow and code organisation
    • Screening
    • 3dvar minimisation
    • 4dvar minimisation
  • User’s guide : scripts and namelists
    • Sequences of execution and Input/Output
    • Most important namelist parameters
    • How to check for the execution ?
    • Frequently encountered ... crashes
  • Domain definitions in ALADIN
  • Aspects of the data distribution on MPP machines

The 3dvar ALADIN was also presented during the 1st ALADIN phasing and maintenance workskop, Budapest, November 2002.


titre documents joints

The variational computations inside ARPEGE/ALADIN cycle CY32

2 February 2007
info document : PostScript
1.1 Mb

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