Changes between Version 6 and Version 7 of GeneralImplementationConcept

Sep 26, 2010, 9:50:52 PM (10 years ago)



  • GeneralImplementationConcept

    v6 v7  
    1010Generally, all three components are independent. In particular, the filters are implemented in the core part of PDAF. To combine the model and observational information one has to define the relation of the observations to the models fields (For example, model fields might be directly observed or the observed quantities are more complex functions of the model fields? In addition, the observations might be available on grid points. If not, interpolation is required.) In addition one has to define the relation of the state vector that is considered in the filter algorithms to the model fields. These relations are defined in separate routines that are supplied to the assimilation system by the user. These routines are called through a well-defined standard interface. To ease the implementation complexity, these user-defined routines can be implemented like routines of the model code. Thus, if a user has experience with the model, it should be rather easy to extend it by the routines required for the assimilation system.
    13 == Attaching PDAF to a model ==
     12== Online and offline assimilation systems ==
    1514There are two possibilities to build a data assimilation system
    1716 1. '''Online mode:''' The model code is extended by calls to PDAF core routines. A single executable is compiled. Whlie running this single executable the necessary ensemble integrations and the actualy assimilation is performed.
    1817PDAF supports both the online and offline modes. Generally, we recommend to use the online mode because it is more efficient on parallel computers. However, the required coding is simpler for the offline than the online mode.
     19== Online mode: Attaching PDAF to a model ==
    2021Here we describe the extensions of the model code for the online mode of PDAF.