from README.MPP, MM5V2.12
-------------------------

B.  How to add a physics module to the MPP framework

The new Schultz scheme is used as an example:

  1.  Add physics package to regular MM5 directory hierarchy

        physics/explicit/schultz/schultz.F
        physics/explicit/schultz/schultz_mic.F

  2.  Modify MPP/mpp_objects_all

        #ifdef IMPHYS7
          REISNER2_OBJ= exmoisg.o rslf.o
        #endif
<new>   #ifdef IMPHYS8
<new>     SCHULTZ_OBJ =   schultz.o schultz_mic.o
<new>   #endif

        MOIST_OBJ = $(NONCONV_OBJ) $(SIMPLE_OBJ) $(LSIMPLE_OBJ) \
<new>                $(SCHULTZ_OBJ) \
                     $(REISNER_OBJ) $(REISNER_S_OBJ) $(LREISNER_OBJ)  ...

      Note that for options that are to be compiled into the code all
      the time, you can add the .o files to BASE_OBJ instead.

  3.  For J-callable routines (eg. schultz.F), add an entry to MPP/FLICFILE

        cflic n=lexmoisr:j,exmoisr:j,exmoisg:j,godmic:j
        cflic n=lexmoiss:j,exmoiss:j
<new>   cflic n=schultz:j
        cflic n=cupara2:j
        cflic n=cupara3:j,cup:j,minimi:j,maximi:j

      What this entry says is that the routine 'schultz' is called from
      within a loop over a decomposed dimension, and that the loop
      index is known as 'J' within the subroutine.   (J is passed in
      through the argument list).

  4.  If FLIC doesn't need to be or shouldn't be called for a routine
      (shultz_mic.F) add a rule to MPP/RSL/Makefile.RSL .

        #
        # These modules are column callable as written, and do not need FLIC.
        #
         [...]
        schultz_mic.o : schultz_mic.F
                $(CUT) -c1-72 $*.F | $(M4_FLIC) - | $(CPP) $(INCLUD...
                $(MFC) -c $(FCFLAGS) $*.f 2> $*.lis

      In the case of schultz_mic(), the routine is called for each i,k
      point individually and there are no decomposed data structures or
      loops within the routine.  FLIC doesn't need to work with this.
      Additionally, schultz_mic() contains FUNCTION declarations, which
      FLIC does not handle.  Rather than break these out in a separate
      file, we just add the whole file to this part of Makefile.RSL and
      avoid using FLIC on it.

  5.  Make uninstall and make mpp.  The make uninstall is to get the
      model to reestablish the symbolic links in the MPP/build
      directory to include the new source files you have added.  The
      mechanism (in MPP/Makelinks) will make a link to any source file
      anywhere in the MM5 source tree, so you don't have to do anything
      else to tell the mechanism where the files are.  It will find
      them automatically.