Changes between Version 5 and Version 6 of PDAFomi_additional_functionality
- Timestamp:
- Nov 24, 2024, 4:53:05 PM (3 hours ago)
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PDAFomi_additional_functionality
v5 v6 61 61 === Activating observation omission === 62 62 63 To use this omission functionality one has to augment [wiki:OMI_observation_modules#init_dim_obs_OBSTYPE ] in the observation modules as follows: [[BR]]63 To use this omission functionality one has to augment [wiki:OMI_observation_modules#init_dim_obs_OBSTYPE init_dim_obs_OBSTYPE] in the observation modules as follows: [[BR]] 64 64 Set the variable 65 65 {{{ … … 74 74 ! (should be much larger than actual observation error variance) 75 75 }}} 76 Thus, the observation is prescribed to have a large error variance and hence has no effect in the assimilation. (The observation is not removed from the assimilation, but just made irrelevant). Depending on the observation, this default value might not be sufficient to make an observation irrelevant. If this is the case, one can also specify a different value of `thisobs%inno_omit_ivar` in the observation module. 76 Thus, the observation is prescribed to have a large error variance and hence has no effect in the assimilation. (The observation is not removed from the assimilation, but just made irrelevant). Depending on the observation, this default value might not be small enough to make an observation irrelevant. If this is the case, one can also specify a different value of `thisobs%inno_omit_ivar` in the observation module. 77 78 || **Note:** From PDAF V2.3.1 one can also call the routines [wiki:PDAFomi_set_inno_omit] and [wiki:PDAFomi_set_inno_omit_ivar] instead of setting the values directly in the code || 77 79 78 80 When `thisobs%inno_omit` is set to >0, you should see a screen output like … … 111 113 In the domain-localized filters (LESTK, LETKF, LSEIK, LNETF) observations are assimilated that are located within the localization around some grid point. When a model uses parallelization with domain-decomposition some of these observations might belong to a different process-domain. In the default mode (`thisobs%use_global_obs`=1) PDAF-OMI gathers all globally available observations so that each process has access to all observations. 112 114 113 It can be more efficient to limit the observations on a process-domain to those observations that are located inside the domain or within the localization radius around it. Then, in the local analyses less observations have to be checked for their distance. Setting `thisobs%use_global_obs=0` activates this feature. However, it needs additional preparations to make PDAF-OMI aware of the limiting coordinates of a process sub-domain.115 It can be more efficient to limit the observations on a process-domain to those observations that are located inside the domain or within the localization radius around it. Then, in the local analyses less observations have to be checked for their distance. Setting `thisobs%use_global_obs=0` (or `CALL PDAFomi_set_use_global_obs(thisobs,0)` from PDAF V2.3.1) activates this feature. However, it needs additional preparations to make PDAF-OMI aware of the limiting coordinates of a process sub-domain. 114 116 115 117 In order to make use of the domain-limited observations, one has to provide PDAF-OMI with the limiting coordinates of a process-subdomain. There are two routines that can to this task:
