Changes between Initial Version and Version 1 of PDAFomi_diag_rmsd

Timestamp:

Mar 27, 2026, 6:01:37 PM (4 days ago)

Author:

lnerger

Comment:

--

PDAFomi_diag_rmsd

@@ +1 @@
+= PDAFomi_diag_rmsd = 
+
+This page documents the routine `PDAFomi_diag_obs_rmsd` of PDAF, which was introduced with PDAF V3.1. This is part of the [wiki:OMI_observation_diagnostics_PDAF3 PDAF-OMI observation diagnostics module].
+
+The routine returns a pointer to a vector of the root-mean square difference (RMSD) between the observations and the observed ensemble mean for each observation type. 
+
+Usually all PDAFomi_diag routines are called in `prepoststep_pdaf` where the observation information can be retrieved and analyzed.
+
+The interface is: 
+{{{
+  SUBROUTINE PDAFomi_diag_rmsd(nobs, rmsd_pointer, verbose)
+
+    INTEGER, INTENT(inout) :: nobs                   ! Number of observation types
+    REAL, POINTER, INTENT(inout) :: rmsd_pointer(:)  ! Vector of RMSD values
+    INTEGER, INTENT(in) :: verbose                   ! Verbosity flag; >0 for screen output
+}}}
+
+For verbose>0 a list of the RMSD for each observation type is printed like
+{{{
+PDAFomi   obs-ID      RMSD   
+PDAFomi      1      7.097E-01
+PDAFomi      2      1.312E-02
+}}}
+
+**Note:**
+ * The computed RMSD is for the global model domain. Thus, in case of a parallelized model, all process sub-domains are taken into account and calling `PDAFomi_diag_obs_rmsd` will return the same value for all processes.
+ * In Fortran user code the pointer should be declared in the form[[BR]] `REAL, POINTER :: rmsd_ptr(:)`[[BR]] It does not need to be allocated. The target vector has the length `nobs`.
+ * If the observation diagnostics have not be activated by using [wiki:PDAFomi_set_obs_diag] the pointer array will not be set and `nobs=0` is returned. One can check this value before assessing the pointer array.
+ * A more extensive set of statistics can be obtained using the routine [wiki:PDAFomi_diag_diffstats].
+
+