Merge pull request #733 from NCAR/THM_variable_doc

THM is mandatory WRF temp variable

models/wrf/model_mod.f90

@@ -694,6 +694,22 @@ subroutine static_init_model()
 
    ! JPH now that we have the domain ID just go ahead and get type indices once
    ! NOTE: this is not strictly necessary - can use only stagger info in the future (???)
+
+   ! Prevent boundscheck error by making WRF temperature variable 'THM' as mandatory. 
+   ! Also, for WRFv4 and later versions variable 'T' is 
+   ! diagnostic, thus updating the 'THM' variable (prognostic) is also preferred
+   ! for all DA applications.
+
+
+
+   if (get_type_ind_from_type_string(id,'T') >=0 .or. get_type_ind_from_type_string(id,'THM') <=0) then
+
+      write(errstring,*)'WRF temperature variable THM must appear in DART model_nml', &
+                        ' for WRFv4 and later'
+      call error_handler(E_ERR,'static_init_model', errstring, source, revision, revdate)
+
+   endif        
+
    wrf%dom(id)%type_u      = get_type_ind_from_type_string(id,'U')
    wrf%dom(id)%type_v      = get_type_ind_from_type_string(id,'V')
    wrf%dom(id)%type_w      = get_type_ind_from_type_string(id,'W')

models/wrf/readme.rst

@@ -24,7 +24,10 @@ Some important WRF-DART updates include:
   operator calculations.
 
 - Version 11.5.0: Improves compatibility with WRFv4+ versions where
-  the prognostic 3D temperature variable is THM.
+  the prognostic 3D temperature variable is THM.  It is now mandatory to
+  include THM instead of T in the ``wrf_state_variables`` namelist.
+
+
 
 It is always recommended that you update your DART version to the 
 `latest release <https://github.com/NCAR/DART/releases>`__ before beginning new research.
@@ -336,6 +339,13 @@ For example:
                            'PSFC','QTY_PRESSURE','TYPE_PS','UPDATE','999',
 
 
+.. Important::
+
+   It is mandatory to include ``THM`` instead of ``T`` as the ``TYPE_T`` WRF 
+   temperature variable. This is because ``THM`` is the prognostic temperature variable
+   that will impact the forecast when updated. 
+
+
 - polar, periodic_x
 
 The ``Polar`` and ``periodic_x`` namelist values are used in global WRF simulations.

models/wrf/tutorial/README.rst

@@ -19,12 +19,14 @@ either WRF or DART.
   versions 11.4.0 and earlier because those older versions do not account
   for different coordinate systems including the sigma hybrid coordinates as 
   described in `DART Issue #650 <https://github.com/NCAR/DART/pull/650>`__.
+  
   Furthermore, older versions do not account for the prognostic temperature variable
   switch from ``T`` (perturbation potential temperature) to ``THM``, (either perturbation
   potential temperature or perturbation moist potential temperature) as described in
   `DART issue #661 <https://github.com/NCAR/DART/issues/661>`__. The current implementation
   of the code sets ``T=THM`` because within &dynamics section of ``namelist.input``
-  ``use_theta_m=0``.
+  ``use_theta_m=0``.  For this reason, It is mandatory to include ``THM`` instead of 
+  ``T`` as the ``TYPE_T`` within the wrf_state_variables namelist.
 
   Earlier version of WRF (v3.9) may run without errors with more recent versions of
   DART (later than 11.4.0), but the assimilation performance will be deprecated.