| 49 | | * Revision of the initialization of observations: Now the observations are initialized before the actual analysis step is computed. Also the observation operator is called before the actual analysis step. This chane allows for the option to initialize observations before prepoststep_pdaf is called for the forecast ensemble. Related to this the screen output for the observations was revised and is displayed at a different place from before. |
| 50 | | * New PDAF3 interface: The selection of possible calls to PDAF*_put_state and PDAF*_assimilate has grown over the years since new functionality, in particular PDAF-OMI and PDAFlocal, required a new interfaces. We now defined a new standard interface in which a single routine (PDAF3_assimilate) can execute all available filter methods for the case of a diagonal observation error covariance matrix. The routine leverages the latest features that were introduced in previous PDAF releases to allow for a minimum number of arguments. There is also the routine PDAF3_put_state, which is now mainly recommended when the offline mode is used. |
| 51 | | * New routine PDAF_get_fcst_info: This routine allows to retrieve the return values of PDAF_get_state (nsteps, time, doexit) for the case that PDAF_assimilate routines, which do not return these values, are used. |
| 52 | | * Change for flexible parallelization variant: It is now possible to use PDAF_assimilate for the flexible parallelization, while PDAF_put_state routines had to be called before. Since PDAF_assimilate is called at each time step during the forecast phase this allows to easy use of the IAU functionality. |
| 53 | | * New routine PDAFomi_set_localize_covar: This routine is called in the OMI observation module in init_dim_obs_pdafomi. It sets the information for localization in the LEnKF and ENSRF/EAKF methods. (optional for LEnKF) |
| 54 | | * Calling LEnKF with the universal routine PDAF3_assimilate: In PDAF 2.3 and before, the LEnKF had its own interface due to the additional call-back routine localize_covar_pdafomi required by this filter. With the new routine PDAFomi_set_localize_covar that is called in the OMI observation module in init_dim_obs_pdafomi the additional user-supplied subroutine localize_covar_pdafomi is no longer required which lowers the amount of implementation work for the user. |
| 55 | | * New routine `PDAF_set_seedset`: This routine can be used to seed the random number seed for PDAF's random number generating routine. |
| 56 | | * Introduced named variables for choosing the filter type: The filter type can now also be specified by a named parameter of the form PDAF_DA_X, where 'X' is the DA method, thus, e.g. 'PDAF_DA_ESTKF'. With this, one does not need to look up the number of the filter type. |
| 57 | | * Added routine 'PDAF_print_filter_types': This routine writes a list of the available filter types and named parameters PDAF_DA_X. |
| 58 | | * Added Fortran function PDAF_localfilter as alternative to subroutine PDAF_get_localfilter to make code more compact |
| 59 | | * Added subroutine PDAF_get_local_type and Fortran function PDAF_local_type. These return information which of the different localization variants a filter uses (no localization, local analysis, covariance localization, covariance localization with serial observation processing) |
| 60 | | * The screen output of the configration of the DA method was revised and provides now a complete configuration overview |
| | 50 | In the flexible parallelization mode of PDAF, one had to use `PDAF_put_state`. With PDAF V3 it is possible, and recommended to use `PDAF_assimilate` instead. This functionality is used in combination with calling `PDAF_get_fcst_info`. |
| | 51 | |
| | 52 | Further information: [wiki:ExternalModelLoop Modification of the model code for the 'flexible' ensemble integration]. |
| | 53 | |
| | 54 | === Covariance localization with `PDAF_set_localize_covar` === |
| | 55 | |
| | 56 | In PDAF2 the localization in the LEnKF required an additional routine localize_covar_pdafomi in each OMI obsevation module. With PDAF V3 one can instead use `PDAF_set_localize_covar`. This routine is called in the observation initialization routine. It is used for the LEnKF and also the ENSRF/EAKF methods. Using this routine also ensemble that the LEnKF can be called using the new universal PDAF3 interface. |
| | 57 | |
| | 58 | Further information: [wiki:PDAFomi_set_localize_covar]. |
| | 59 | |
| | 60 | === Initializing observations before prepoststep_pdaf === |
| | 61 | |
| | 62 | In PDAF V3 one can choose to initialize observations after an analysis phase before the routine prepoststep_pdaf is called. This is set using the integer parameter with index 9 (see [wiki:AvailableOptionsforInitPDAFinPDAF3 Options for PDAF_init]). This option allows the code to assess observation information in prepostep_pdaf to compute the forecast ensemble with the observations that will be assimilated in the following analysis step. |
| | 63 | |
| | 64 | Further information: [wiki:AvailableOptionsforInitPDAFinPDAF3 Options for PDAF_init] and [wiki:PDAFomi_observation_diagnostics PDAFomi observation diagnostics] |
| | 65 | |
| | 66 | === Setting random number seed in PDAF === |
| | 67 | |
| | 68 | The new routine `PDAF_set_seedset` provided the possibility to select a set of random number seeds (out of 20 choices). This allows to perform, e.g. sensitivity tests by rerunning a dta assimilation case with different random numbers. |
| | 69 | |
| | 70 | Further information: [wiki:PDAF_set_seedset] |
| | 71 | |
| | 72 | === Named variable for filtertype === |
| | 73 | |
| | 74 | The module `PDAF` provides now a names variable for each filter type. The names are of the structure `PDAF_DA_X`, where 'X' is the assimilation method. Thus, one can specify a filtertype in the call to `PDAF_init` as `PDAF_DA_LESTKF` instead of the number 7. |
| | 75 | |
| | 76 | === Printing filtertype names and numbers === |
| | 77 | |
| | 78 | The named filtertypes (`PDAF_DA_X`) can be listed by calling the routine `PDAF_print_filter_types`. |
| | 79 | |
| | 80 | Further information: [wiki:PDAF_print_filter_types]. |
| | 81 | |
| | 82 | === Checking for type of localization === |
| | 83 | |
| | 84 | Checking whether a filter uses localization can now be done using the Fortran function (instead of subroutine) `PDAF_localfilter`. The return value will be =1 for domain localized filters (e.g. LESTKF, LETKF) and 0 otherwise.[[BR]] |
| | 85 | The function `PDAF_get_local type` allows to distinguish global filters, domain localization and covariance localization (e.g. LEnKF and ENSRF/EAKF). |
| | 86 | |
| | 87 | Further information: [wiki:PDAF_localfilter] and [wiki:PDAF_get_local_type]. |
| | 88 | |
