| | 155 | == PDAF_set_comm_pdaf == |
| | 156 | |
| | 157 | This routie allows to sepacify the communicator on which the overall PDAF communication bases. |
| | 158 | |
| | 159 | By default, PDAF bases on `MPI_COMM_WORLD`, thus all processes in a program. This routine allows to set a different communicator. This can be useful if a model is e.g. run with an OI-server so that the world communicator is split into processes for the IO (file) operations and other processes for the actual model run. In this casem, the model would run using a communicator distinct from `MPI_COMM_WORLD` and PDAF should operate only with this communicator. `PDAF_set_comm_pdaf` allows the user to specify this communicator for PDAF. |
| | 160 | |
| | 161 | {{{ |
| | 162 | SUBROUTINE PDAF_set_comm_pdaf(comm_pdaf) |
| | 163 | |
| | 164 | INTEGER,INTENT(in) :: comm_pdaf ! MPI communicator for PDAF |
| | 165 | }}} |
| | 166 | |
| | 167 | Notes: |
| | 168 | * `comm_pdaf` has to be used consistently in `init_parallel_pdaf` where the commuicators for PDAF are prepared on the user side. |
| | 169 | * The size of `comm_pdaf` has to be large enough so that the ensemble run can be performed |
| | 170 | * `PDAF_set_comm_pdaf` has to be called before calling `PDAF_init` |
| | 171 | |
| | 172 | |
| | 173 | |
| | 174 | == PDAF_reset_forget == |
| | 175 | |
| | 176 | This routine was introduced with PDAF V2.0 |
| | 177 | |
| | 178 | The routine allows a user to reset the forgetting factor manually during the assimilation process. |
| | 179 | |
| | 180 | For the local ensemble Kalman filters the forgetting factor can be set either globally of differently for each local analysis domain. For the LNETF and the global filters only a global setting of the forgeting factor is possible. This routine allows users to set the forgetting factor case-specific. In addition, the implementation of adaptive choices for the forgetting factor (beyond what is implemented in PDAF) are possible. |
| | 181 | |
| | 182 | The interface is the following: |
| | 183 | {{{ |
| | 184 | SUBROUTINE PDAF_reset_forget(forget) |
| | 185 | }}} |
| | 186 | with the following argument: |
| | 187 | * `forget`: `real, intent(in)`[[BR]] The new value of the forgetting factor |
| | 188 | |
| | 189 | '''How to use PDAF_reset_forget''' |
| | 190 | |
| | 191 | * '''Global Filters and LNETF''': For global filters `PDAF_reset_forget` has to be called before the actual analysis step. Within the PDAF context the call can be inserted in `prepoststep_pdaf`. Alternatively, the call can be inserted in the routine `assimilation_pdaf` before the call to the PDAF_assimilate_X or PDAF_put_state_X routines |
| | 192 | * '''Local Filters''': |
| | 193 | * global setting: The forgetting factor is reset globally, thus equal for all local analysis dimains, if `PDAF_reset_forget` is called before the local analysis loop is executed (e.g. in `init_obs_pdomi` or earlier in the analysis step; see [ImplementAnalysisLocal] for the order of the execution of the call-back routines). Thus, it can also be called in `prepoststep_pdaf` to get a global seeting as fo rthe global filters. |
| | 194 | * To reset `forget` specific for each local analysis domain, `PDAF_reset_forget` should be called during the local analysis loop. In particular the routines `init_dim_l` or `init_dim_obs_l_pdafomi` are suited for this. |
| | 195 | |
| | 196 | |
| | 197 | = PDAF_force_analysis = |
| | 198 | |
| | 199 | This routine was introduced with PDAF 2.0. |
| | 200 | |
| | 201 | The routine allows a user to enforce the execution of the analysis step at the next call to `PDAF_put_state_X` or `PDAF_assimilate_X`. |
| | 202 | |
| | 203 | In particular for `PDAF_assimilate_X`, the number of time steps is set before the forecast phase is entered. However, one might not know the actual length of the forecast time, e.g. the time when new observation arrive. In this case, one can set for number of time steps to a large value and then check for new observations during the time stepping and call `PDAF_force_analysis` just before `PDAF_assimilate_X` is called to enforce that the analysis step is executed. |
| | 204 | |
| | 205 | [[span(style=color: #FF0000, '''Warning:''' This is a routine for advanced functionality of PDAF. Use it carefully, since it can break the assimilation process.)]] |
| | 206 | |
| | 207 | For `PDAF_put_state_X`, one can use `PDAF_force_analysis` to overwrite the counting of the ensemble members that PDAF does internally. |
| | 208 | |
| | 209 | {{{ |
| | 210 | SUBROUTINE PDAF_reset_forget() |
| | 211 | }}} |
| | 212 | without any argument |
| | 213 | |
| | 214 | |
| | 215 | = PDAF_set_memberid = |
| | 216 | |
| | 217 | This routine was introduced with PDAF 2.0. |
| | 218 | |
| | 219 | The routine allows a user to reset the ensemble member counter inside PDAF. This routine should only be used in the flexible parallelization mode, thus when `PDAF_put_state_X` is used. Resetting the member counter, allows e.g. to enforce the execution of the analysis step in the case, when according to the PDAF-internal counter, the ensemble integration is not yet complete. For this, one has to specify the member-ID to be the ensemble size. |
| | 220 | |
| | 221 | To just enforce an analysis step, we recommend to use the routine [wiki:PDAF_force_analysis]. This routine is also compatible with `PDAF_assimilate_X`. |
| | 222 | |
| | 223 | [[span(style=color: #FF0000, '''Warning:''' This is a routine for advanced functionality of PDAF. Use it carefully, since it can break the assimilation process.)]] |
| | 224 | |
| | 225 | The interface is the following: |
| | 226 | {{{ |
| | 227 | SUBROUTINE PDAF_set_memberid(member) |
| | 228 | }}} |
| | 229 | without the argument: |
| | 230 | * `member`: `integer, intent(in)` Member in index to which the PDAF-internal counting is reset. |
