Functionality for gauge-evaluate only option

Made changes to the streamflow obs convertor to allow
for evaluate only option for gauges that are not desired
(i.e., gauges user didn't select but are part of the USGS network
in the domain)

models/wrf_hydro/create_identity_streamflow_obs.f90

@@ -66,7 +66,7 @@ program create_identity_streamflow_obs
 integer,  parameter :: NUM_COPIES      = 1      ! number of copies in sequence
 integer,  parameter :: NUM_QC          = 1      ! number of QC entries
 real(r8), parameter :: MIN_OBS_ERR_STD = 0.1_r8 ! m^3/sec
-real(r8), parameter :: MAX_OBS_ERR_STD = 100000.0_r8 
+real(r8), parameter :: MAX_OBS_ERR_STD = 1000000.0_r8 
 real(r8), parameter :: NORMAL_FLOW     = 10.0_r8
 real(r8), parameter :: contract        = 0.001_r8
 
@@ -104,7 +104,7 @@ program create_identity_streamflow_obs
 real(r8),                       allocatable :: discharge(:)
 
 character(len=IDLength),        allocatable :: desired_gages(:)
-integer         :: n_wanted_gages
+integer         :: n_wanted_gages, n_desired_gages
 real(r8)        :: oerr, qc
 integer         :: oday, osec
 type(obs_type)  :: obs
@@ -209,9 +209,18 @@ program create_identity_streamflow_obs
 call init_obs(obs,      num_copies=NUM_COPIES, num_qc=NUM_QC)
 call init_obs(prev_obs, num_copies=NUM_COPIES, num_qc=NUM_QC)
 
-n_wanted_gages = set_desired_gages(gages_list_file)
+! MEG 6/29/23 [Commented out set_desired_gages(gages_list_file)]
+! Collect all the gauges: 
+! - desired ones will have the provided obs_err_sd
+! - remaining gauges are dummy with very large obs_err_sd
+
+n_desired_gages = set_desired_gages(gages_list_file)
+n_wanted_gages  = 0 !set_desired_gages(gages_list_file)
 call find_textfile_dims(input_files, nfiles)
 
+print *, gages_list_file
+print *, 'n_wanted_gages: ', n_wanted_gages
+
 num_new_obs = estimate_total_obs_count(input_files, nfiles)
 
 inquire(file=output_file, exist=file_exist)
@@ -316,12 +325,21 @@ program create_identity_streamflow_obs
       if (indx == 0) cycle OBSLOOP
 
       ! relate the physical location to the dart state vector index
-      dart_index = linkloc_to_dart(lat(indx), lon(indx))
+      dart_index = linkloc_to_dart(lat(indx), lon(indx)) 
+
+      ! desired gauges get the provided obs_err
+      ! remaining ones are for verification purposes
+      if (ANY(desired_gages == station_strings(n))) then  
+        oerr = max(discharge(n)*obs_fraction_for_error, MIN_OBS_ERR_STD)
+      else 
+        oerr = MAX_OBS_ERR_STD
+      endif
 
+      ! MEG: 6/29/23 [Commented out, oerr is conditionally computed now]
       ! oerr is the observation error standard deviation in this application.
       ! The observation error variance encoded in the observation file
       ! will be oerr*oerr
-      oerr = max(discharge(n)*obs_fraction_for_error, MIN_OBS_ERR_STD)
+      !oerr = max(discharge(n)*obs_fraction_for_error, MIN_OBS_ERR_STD)
 
       ! MEG: A fix to not crush the ensemble in a no-flood period (stagnant water).  
       !if ( discharge(n) < NORMAL_FLOW ) then