Model Change Bulletin

                                MCB#4                              

                        PCRAMMET (dated 99169)



     This Model Change Bulletin initiates the update of the PCRAMMET (dated 
99169) program located on the SCRAM web site under Models/Related Programs.

     PCRAMMET (dated 99169) begins the Year 2000 compliant version of
PCRAMMET.  The program has been successfully tested for operability in the
next millenium.  Minor changes to the source code were made.  

     In addition, the first test case was changed from a Year 1994 HUSWO
testcase to a Year 2000 HUSWO testcase.  In the other four testcases, the
output file was updated due to a slight change in rounding of the interpolated
mixing height data output (e.g. 1000.0 vs 1000.1, 778.9 vs 778.8)  If at all, 
this rounding difference occurred in no more than 7 out of the 8760 to 8784 
hours in a year.  The change in output is attributed to the change in compilers 
as the input data are identical and the mixing height algorithm has not been
altered.

     The PCRAMMET User's Guide was updated to change the compilation
procedures from Lahey F77L-32 to Lahey Fortran 90 (pages 5-1 to 5-3).  In
addition, an attention statement is described (page 6-1).  This message is
issued when the program first reads ASOS data from a HUSWO dataset.  See the
PCRAMMET User's Guide for further details.  The PCRAMMET User's Guide is in 
PDF format.

     PCRAMMET is offered only in Lahey-compiled format on the SCRAM web site.  
This compiler requires that a floating point unit be available either on the 
main processor (Intel 80486 DX or better) or a separate math coprocessor.

     This program will henceforth be identified by its name and a Julian
date, i.e.: PCRAMMET (dated 99169).  Future changes to this program will be
identified by an updated Julian date found on the first line of the model
source code and followed by a reference to a SCRAM web site Model Change
Bulletin (MCB#n) which will explain the nature and contents of the changes.
All Model Change Bulletins for this program will always be available for
back reference on this web site. In the future, notification of changes
(MCBs) to this model will be made in the Model Change Bulletins/Related
Programs section of this web site.