Changes between Version 27 and Version 28 of GeneralImplementationConcept

Timestamp:

May 30, 2025, 5:52:55 PM (3 days ago)

Author:

lnerger

Comment:

--

GeneralImplementationConcept

@@ -18 +18 @@
 
 Data assimilation requires 3 components. These are
- * **Model**:[[BR]] The numerical model provides the initialization and integration of all model fields. It defines the dynamics of the system that is simulated. This provides the first source of information on the system.
+ * **Model**:[[BR]] The numerical model provides the initialization and time development of all model fields. It defines the dynamics of the system that is simulated. This provides the first source of information on the system.
  * **Observations**:[[BR]] The observations of the system provide the second source of information. 
  * **Assimilation method**:[[BR]] The assimilation method combines the information from the model and observations. 
@@ -30 +30 @@
 PDAF combines these three components, which are otherwise independent. 
 * The **model** is provided by the user. It computes the time evolution of the model fields. For the data assimilation, it provides information on the model state fields, the time, and the model grid to the other components.
-* The **assimilation methods** (DA methods) are implemented in the core part of PDAF. They obtain information from the model and the observations and operate on abstract state vectors. For this, one has to fill and ensemble of state vectors with the values of the model fields. After the assimilation update, the analysis state vector is written back to the model fields. This functionality is implemented in separate routines that are supplied to the assimilation system by the user. The DA methods also interacts with the observations, providing the state vectors to the observation operator and obtaining observed model state vectors. 
-* Information on **observations** (observation values, their coordinates and error estimates) have to be read from files. Further, one has to define the observation operator, which computes the model equivalent to the observations. PDAF-OMI provides a structured way for the handling of observations and to provide PDAF with the required information. 
+* Information on **observations** (observation values, their coordinates and error estimates) have to be read from files. Further, one has to define the observation operator, which computes the model equivalent to the observations. The PDAF Observation Module Interface (PDAF-OMI) provides a structured way for the handling of observations and to provide PDAF with the required information. 
+* The **assimilation methods** (DA methods) are implemented in the core part of PDAF. They obtain information from the model and the observations and operate on abstract state vectors. For this, one has to fill an ensemble of state vectors with the values of the model fields. After the assimilation update, the analysis state vector is written back to the model fields, or to restart files of the model for offline coupling. This functionality is implemented in separate routines that are supplied to the assimilation system by the user. The DA methods also interacts with the observations. PDAF provides the state vectors to the observation operator and obtaining observed model state vectors. Further the vector of observations, their error and coordinates to provided by PDAF-OMI.
 
 Both, the subroutines of PDAF and the user-provided subroutines are called through a well-defined standard interface. To ease the implementation complexity, the 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.