Model Change Bulletin

                                MCB#5                       06/30/2015

                        AERSCREEN (dated 15181)

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 15181) includes the following
modifications relative to the previous version (14147):

Enhancements

1.  Added subroutine FUMINP to prompt user for inversion break-up and
    shoreline fumigation inputs, including distance from source to shoreline,
    optional direction from source to shoreline, and option to not run the 
    full AERSCREEN program and only run fumigation calculations.
2.  Added subroutine SUBSETMET to determine stable hours from meteorological files
    that fit criteria for fumigation, F stability and stack top wind speed of 2.5 m/s.
3.  Added subroutine RECALCPLUME to calculate effective plume heights for fumigation.
4.  Added function THETA to calculate potential temperature and potential temperature
    gradient at specified height.
5.  Added subroutine BRUNT to calculate Brunt-Vaisala frequency from potential
    temperature and potential temperature gradient.
6.  Added subroutine BID to calculate sigma-y and sigma-z contributions from
    buoyancy induced turbulence.
7.  Added functions SIGMAV and SIGMAW to calculate sigma-v and sigma-w.
8.  Added functions SIGMAY and SIGMAZ to calculate sigam-y and sigma-z.
9.  Modified subroutine plumehght to output potential temperature,
    potential temperature gradient, plume flux due to buoyancy, and
    plume flux due to momentum as well as calculate plume height under
    stable conditions.
10. Added subroutine FUMIGATE and INVMAX to loop through stable hours
    to calculate inversion break-up fumigation concentrations.
11. Added subroutines SHORELINE, SHOREMAX, and TIBL to calculate
    shoreline fumigation concentrations.
12. Added debug option to output intermediate outputs from PROBE,
    FLOWSECTOR, SUBSETMET, INVMAX, and SHORELINE.
13. Modified subroutine FINDSEC to accomodate optional source to
    shoreline direction.



Miscellaneous

1.  Eliminated system calls to copy files and use write statements instead
    to make code more portable across operating systems.
2.  Eliminated system calls to delete files and use close statements instead
    to make code more portable across operating systems.
3.  No longer copy surface and profile files to AERSCREEN.SFC and AERSCREEN.PFL,
    instead using actual filenames.
4.  Added diagonal angle for AREA sources in maximum concentrations file.
5.  Make variables RUNDATE and RUNTIME global variables.
6.  Modified subroutine METDATA that if user selects option 3 for
    surface characteristics by accident, enter return to return
    to option selection when prompted for filename.
7.  Modified subroutine MAKEMET2 to enter "N" for surface friction
    velocity adjustment in MAKEMET version 15181 when called by AERSCREEN.

Bug Fixes
1.  Corrected bug in WRITETOLOG for flare diameter output.