Changes between Initial Version and Version 1 of PDAFomi_diag_stats

Timestamp:

Mar 23, 2025, 8:53:26 AM (10 days ago)

Author:

lnerger

Comment:

--

PDAFomi_diag_stats

@@ +1 @@
+= PDAFomi_diag_stats = 
+
+This page documents the routine `PDAFomi_diag_stats` of PDAF, which was introduced with PDAF V3.0. This is part of the PDAF-OMI observation diagnostics module. 
+
+The routine returns 
+a pointer to an array of a selection of 6 statistics comparing 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. These statistics can, for exmaple, be used to plot a Taylor diagram.
+
+The interface is the following: 
+{{{
+  SUBROUTINE PDAFomi_diag_stats(nobs, obsstats_ptr, verbose)
+}}}
+with the following arguments:
+{{{
+    INTEGER, INTENT(inout) :: nobs                     ! Number of observation types
+    REAL, POINTER, INTENT(inout) :: obsstats_ptr(:,:)  ! Array of observation statistics; content:
+                                                       ! (1,:) correlations between observation and observed ensemble mean
+                                                       ! (2,:) centered RMSD between observation and observed ensemble mean
+                                                       ! (3,:) mean bias for observation minus observed ensemble mean
+                                                       ! (4,:) mean absolute difference between observation and observed ensemble mean
+                                                       ! (5,:) variance of observations
+                                                       ! (6,:) variance of observed ensemble mean
+    INTEGER, INTENT(in) :: verbose                     ! Verbosity flag
+}}}
+
+**Note:**
+ * The computed statistics are for the global model domain. Thus, in case of a parallelized model, all process sub-domains are taken into account and calling `PDAFomi_diag_stats` will return the same value for all processes.
+ * In Fortran user code the pointer should be declared in the form[[BR]] `REAL, POINTER :: obsstats_ptr(:)`[[BR]] It does not need to be allocated.. The target array has the size `(6, 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. One can check this value before assessing the pointer array
+ * The routine returns the centered RMSD as displayed in Taylor diagrams. The non-centered RMSD can be computed using [wiki:PDAFomi_diag_obs_rmsd].
+
+