Model Change Bulletin

                               MCB#5                       3/29/94

                       CTSCREEN (dated 94111)


     This Model Change Bulletin is to notify users of changes
made to correct problems in CTSCREEN (dated 93228).  The specific
changes, the problems addressed, and the consequences of the
changes are summarized below.

     These revisions constitute CTSCREEN (dated 94111) and
completely replace CTSCREEN (dated 93228).  With this bulletin,
the source codes and executables for CTSCREEN (dated 94111) are
being made available for downloading from the Air Quality Models
area of the File Transfer Section of SCRAM.  CTSCREEN (dated
93228) is obsolete and, with this bulletin, will no longer be
available on SCRAM.  All copies of such should be discarded.


1.   Problems associated with the SUMRE file

PROBLEM:

      There was a problem with the SUMRE file produced by CTSCREEN
(dated 93228) that were reported by users.  The source contribution
reported in the receptor summary in the SUMRE file was incorrect
for unstable hours.  There was no problem with the source contribution
for stable hours.

SOLUTION:

      This problem has been remedied in CTSCREEN (dated 94111).

SUBROUTINES MODIFIED:
      WRITSCR.FOR


2.  Contacts for Questions (NO CHANGE)

     Questions related to the use of CTSCREEN in specific
regulatory applications should be directed to the appropriate
regulatory agency or Regional Modeling Contact (see State/Local
Modeling Contacts in the Agency Communications Section of SCRAM).

     Generic questions related to the use and regulatory
applicability of the model should be directed to Desmond Bailey
via SCRAM EMAIL or phone (919) 541-5248.

     Questions or problems related to program execution should be
reported to Donna Schwede via SCRAM EMAIL or phone (919) 541-3255
or to Steve Perry phone (919) 541-1341.

     Users who would like to share comments, suggestions, or
helpful hints are encouraged to use the Model Conferencing area
on the SCRAM Bulletin Board (see Model Conferencing area in the
Public Communications Section of SCRAM).


     Technical correspondence should be directed to:

     Ms. Donna Schwede or
     Dr. Steven Perry
     Applied Modeling Research Branch
     ACMD/AREAL/USEPA
     MD-80
     Research Triangle Park, NC  27711

     Fax: (919) 541-1379