Fix for Schultz Microphysics (IMPHYS=8)
      for MM5v3 Release 2 (and probably Release 1)
      Also affects V2.12 (see end of this message)
--------------------------------------------------

The bug will cause "window" like patterns in the output, especially
in the vertical wind velocity and moisture fields, on multiple distributed
memory processors. The windows correspond to processor boundaries, and it
is the result missing halo values for horizontal advection of the QGA, QGB,
QNCA, and QNCB moisture quantities in solve.  This fix adds those quantities
to the stencil definition for STEN_A when IMPHYS=8.  The bug only affects
the SCHULTZ (IMPHYS=8) microphysics option.

This fix applies to all platforms that use the MPP version of MM5.

Edit the file:

   MPP/RSL/parallel_src/define_comms.F

Around line 331, comment out the line:

          IF(IMPHYS(INEST).EQ.6.OR.IMPHYS(INEST).EQ.7)THEN

and replace the line with:

          IF(IMPHYS(INEST).GE.6)THEN

The changed code should look like this.


      IF(IMOIST(INEST).EQ.2)THEN
        call rsl_build_message(msg,RSL_REAL,qca,3,decomp,glen,llen)
        call rsl_build_message(msg,RSL_REAL,qcb,3,decomp,glen,llen)
        call rsl_build_message(msg,RSL_REAL,qra,3,decomp,glen,llen)
        call rsl_build_message(msg,RSL_REAL,qrb,3,decomp,glen,llen)
        IF(IMPHYS(INEST).GE.5)THEN
          call rsl_build_message(msg,RSL_REAL,qia,3,decomp,glen,llen)
          call rsl_build_message(msg,RSL_REAL,qib,3,decomp,glen,llen)
          call rsl_build_message(msg,RSL_REAL,qnia,3,decomp,glen,llen)
          call rsl_build_message(msg,RSL_REAL,qnib,3,decomp,glen,llen)  <<< LINE 330
C          IF(IMPHYS(INEST).EQ.6.OR.IMPHYS(INEST).EQ.7)THEN
          IF(IMPHYS(INEST).GE.6)THEN
            call rsl_build_message(msg,RSL_REAL,qga,3,decomp,glen,llen)
            call rsl_build_message(msg,RSL_REAL,qgb,3,decomp,glen,llen)
            call rsl_build_message(msg,RSL_REAL,qnca,3,decomp,glen,llen)
            call rsl_build_message(msg,RSL_REAL,qncb,3,decomp,glen,llen)
          ENDIF
        ENDIF
      ENDIF

Save the edited file and then in the top level directory (the directory
that contains the configure.user file) type "make mpp".  It is not
necessary to type "make mpclean" first to pick up this correction.

__________________________________________________________________
NOTE TO V2.12 users:

 (Users are urged to upgrade to MM5v3 as soon as expedient.)

  The fix to V3 for Schultz microphysics also applies to the the MPP
  version of the V2.12 code as well.  The affected V2 file is
  MPP/RSL/parallel_src/define_comms.F and the line to comment out and
  replace occurs at line 367:

c          IF(IMPHYS(INEST).EQ.6.OR.IMPHYS(INEST).EQ.7)THEN
          IF(IMPHYS(INEST).GE.6)THEN

  As with the V3 correction, this only affects the Schultz micro
  physics option.

------------------------------------------------------------------

-Rotang, Nov. 9, 1999