INTRODUCTION
------------

This is the README file for the CAMx model that includes information about:
1) License agreement
2) CAMx e-mail contacts
3) Upgrading to the latest version of CAMx
4) The distributed test case

Further details about CAMx are provided in the Release Notes and in the CAMx
User's Guide, available from www.camx.com.


1. LICENSE AGREEMENT
--------------------

Read the "LICENSE" file included with the source code.
The LICENSE is also accessible from the CAMx website download page:
https://www.camx.com/download/
or directly via:
http://camx.com/Files/LICENSE.txt
You agree to the CAMx license terms by downloading the source code and using
the CAMx model.


2. CAMx E-MAIL CONTACTS
-----------------------

Join the CAMx User's Group by sending an e-mail message to:

 camxdevel at gmail dot com

with the words “subscribe CAMxusers” in the BODY of the message.  You will
receive an invitation to join the Google Group along with additional
information on how to use this service.

The camxusers group is meant for broadcasting useful information about CAMx
and its pre- and post-processors to all users that subscribe to this group, or
to ask about available datasets or issues that other users may have come across.
It is not meant for asking how to run CAMx, how to prepare inputs, or why CAMx
arrived at a particular prediction.

         ** PLEASE REFER TO THE CAMx USER'S GUIDE FIRST **


3. UPGRADING TO CAMx V7 FROM PREVIOUS VERSIONS
----------------------------------------------

V7.x is a major update from previous releases (v6.x). 
Version 7 introduces netCDF input file formats for all large gridded arrays:
meteorology, landcover, initial/boundary/top concentrations, point sources,
2-D and 3-D emissions.  Output concentration, deposition and Probing Tool files
are also generated in netCDF format (since v6.5). The Fortran binary I/O formats
are removed in v7.40, so no binary I/O files generated for v7.3 or earlier can
be used. Such input files must be regenerated or converted.

Multiple point, 2-D and 3-D emission files can be provided to CAMx and Probing
Tools, alleviating the need to merge component emissions into single input
files.

NOTE on Source Apportionment Technology (SAT): With this change, SAT input
      point source emission files are used to define emissions for BOTH the
      core model and the SAT application.  In earlier CAMx versions, separate
      sets of core and SAT point source files were listed and the model compared
      SAT point emissions to core model inputs to ensure consistency.  Now ALL
      SAT point emissions are always used for BOTH SAT and the core model.  A
      "leftover" capability remains available for gridded emissions, based on
      differences between SAT emission inputs and core model emission inputs,
      but not for point emissions. It is no longer necessary to provide a
      consistent list of point sources among all of the SAT point source
      files.  The list of points to model are now an internal concatonation
      of point source lists from each input SAT point source file.

NOTE on DDM and RTRAC: With this change, DDM and RTRAC input point source
      emission files can include stack lists that are entirely unique to
      these Probing Tools.  Earlier CAMx versions required a consistent list
      of point sources among the core model, DDM and RTRAC, which was
      onerous.  This restriction is removed.

See the User's Guide for more information on file formats, requirements and
restrictions.

Refer to the namelist template provided with the source code and the User's
Guide for a full list of namelist variables for this version.  Some new
variables have been added.

Visit www.camx.com to obtain the latest code, version-specific input files 
(e.g., chemistry parameters) and all test case I/O.


4. CAMx TEST CASE
-----------------

A test case is provided to help new CAMx User's get started and permit
performance benchmarking.  The test case is based on the US EPA's 2016 Modeling
Platform, with a single nested domain covering the Eastern U.S.  The test case
includes inputs and outputs for 2 days of simulation over June 10-11, 2016,
which are available at www.camx.com.

You can compare your results to the test case benchmark by displaying
the concentration outputs using graphics programs.  We expect concentrations
to agree within the limits of single precision calculation, namely relative
errors of about 1 in 100,000.
