Model Change Bulletin

                                MCB#4                       05/27/2014

                        AERSCREEN (dated 14147)

This Model Change Bulletin (MCB) documents changes made to the AERSCREEN 
screening model.  A brief description of the changes is provided below. 
Additional details are available in the FORTRAN source code and in 
the AERSCREEN user's guide.


This revised version of AERSCREEN (dated 14147) includes the following
modifications relative to the previous version (11126):

Modifications

1.  Modified subroutines MAKETERRAIN and MAKEGRID to include a new variable,
    REFDIST for calculating receptors for the REFINE stage.  Previously, the
    variable NUMPT was used in these subroutines to represent the number of 
    receptor points for the PROBE and FLOWSECTOR stages and distance for
    the REFINE stage.  REFDIST was created to avoid confusion with different
    meanings of NUMPT.  REFDIST is also set to the probe distance if REFDIST
    exceeds the probe distance.
2.  Modifed subroutine MAKEINPUT to eliminate a blank line as the first line
    of the AERMOD input file.  This makes AERSCREEN compatible with AERMOD
    version 14134 and later due to the skipping of blank lines in AERMOD (see
    miscellaneous change #3 of AERMOD MCB #10).
3.  Modified subroutine FINDMAX to read the AERMOD version number from AERSCREEN.FIL
    so that it is independent of the AERMOD version.  Previous versions of AERSCREEN
    read the version number using a fixed format that changed with AERMOD 12345.
    AERSCREEN no longer uses a fixed format to read the version number and is flexible
    for later AERMOD versions.

Bug Fixes

1.  Modified subroutine READINP to set the discrete receptor use flag
    DISCFLAG to N instead of setting the logical variable DISCDAT to N.
    Previous versions of AERSCREEN were setting the wrong variable (DISCDAT).