README -- Describes contents of HEMCO/O3/v2014-09 directory
18 Feb 2015
GEOS-Chem Support Team
geos-chem-support@g.harvard.edu


Overview:
===============================================================================

This data directory contains monthly mean O3 concentration data, which is used
as an input by several of GEOS-Chem's specialty simulations.

The files were created by merging tropospheric O3 data saved out from a
GEOS-Chem simulation with stratospheric data saved out from a GMI model
simulation.  Chris Holmes was the author.

These netCDF files were created from the bpch files in the old data directory
sulfate_sim_200508/offline.


Files:
===============================================================================

MERGE.O3.gcap.23L.4x5.nc    : O3 on 23-layer GCAP   4 x 5   horizontal grid
MERGE.O3.geos4.30L.2x25.nc  : O3 on 30-layer GEOS-4 2 x 2.5 horizontal grid
MERGE.O3.geos4.30L.4x5.nc   : O3 on 30-layer GEOS-4 4 x 5   horizontal grid
MERGE.O3.geos4.55L.2x25.nc  : O3 on 55-layer GEOS-4 2 x 2.5 horizontal grid
MERGE.O3.geos4.55L.4x5.nc   : O3 on 55-layer GEOS-4 2 x 2.5 horizontal grid
MERGE.O3.geos5.47L.2x25.nc  : O3 on 47-layer GEOS-5 2 x 2.5 horizontal grid
MERGE.O3.geos5.47L.4x5.nc   : O3 on 47-layer GEOS-4 4 x 5   horizontal grid
MERGE.O3.geos5.72L.2x25.nc  : O3 on 72-layer GEOS-4 2 x 2.5 horizontal grid
MERGE.O3.geos5.72L.4x5.nc   : O3 on 72-layer GEOS-4 4 x 5   horizontal grid
MERGE.O3.geosfp.47L.2x25.nc : symbolic link to MERGE.O3.geos5.47L.2x25.nc
MERGE.O3.geosfp.47L.4x5.nc  : symbolic link to MERGE.O3.geos5.47L.4x5.nc 
MERGE.O3.geosfp.72L.2x25.nc : symbolic link to MERGE.O3.geos5.72L.2x25.nc
MERGE.O3.merra.47L.2x25.nc  : symbolic link to MERGE.O3.geos5.47L.2x25.nc
MERGE.O3.merra.47L.4x5.nc   : symbolic link to MERGE.O3.geos5.47L.4x5.nc
MERGE.O3.merra.72L.2x25.nc  : symbolic link to MERGE.O3.geos5.72L.2x25.nc
MERGE.O3.merra.72L.4x5.nc   : symbolic link to MERGE.O3.geos5.72L.4x5.nc

-- For all files:
   Units                       : vol/vol mixing ratio
   Timestamps                  : Monthly, 1985/01 thru 1985/12
   Compression                 : Level 1 (e.g. nccopy -d1)

###############################################################################
#####  NOTE: For most simulations, you can specify that you want to read  #####
#####  OH data from the MERGE.O3.geos5.72L.2x25.nc filee, and HEMCO will  #####
#####  perform the vertical and horizontal regridding.                    #####
#####                                                                     #####
#####  We will keep the O3 files defined on other other vertical and      #####
#####  horizontal grids for backwards compatibility.                      #####
#####                                                                     #####
#####    -- Bob Yantosca (12 Mar 2015)                                    #####
###############################################################################


How the netCDF files were created:
===============================================================================

The files in this directory were created from the original data files in
binary punch format.  NetCDF files were generated from the bpch files with
GAMAP routine BPCH2COARDS.

Bob Yantosca wrote the following script to adjust the netCDF attributes for 
better COARDS compliance.

   #!/bin/tcsh
   
   # Fixes attributes
   
   ncatted -a axis,time,o,c,"T" $1
   
   ncatted -a long_name,lev,o,c,"GEOS-Chem levels" $1
   ncatted -a axis,lev,o,c,"Z" $1
   ncatted -a positive,lev,o,c,"up" $1
   
   ncatted -a axis,lat,o,c,"Y" $1
   
   ncatted -a axis,lon,o,c,"X" $1
   
   ncatted -a References,global,o,c,"www.geos-chem.org; wiki.geos-chem.org" $1
   ncatted -a Format,global,o,c,"NetCDF-3" $1
   
   exit(0)

NOTE: Using "GEOS-Chem levels" for the level dimension will allow HEMCO to
perform the vertical regridding.