README -- Describes contents of the HEMCO/SfcFix/v2019-12 directory
18 Dec 2019
GEOS-Chem Support Team
geos-chem-support@g.harvard.edu


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

This directory contains NetCDF files of spatially-resolved species
concentrations.  These are used by GEOS-Chem/HEMCO to fix concentrations of
certain long-lived species in the planetary boundary layer.

The files for OCS and H2 (surface_vmr_?.nc) contain a spatial field with a
single value for all locations. Values of 500 pptv and 500 ppbv are present
for OCS and H2 respectively. Please contact Tomas Sherwen
(tomas.sherwen@york.ac.uk) with any questions or to report any issues about
H2/OCS files.

The WMO_2018 (originally "GMI") and WMO_2006 (originall "UCX") subfolders
each contain a single NetCDF with spatially and temporally resolved fields
for multiple long-lived species. These files were processed from the
existing HEMCO data used by GEOS-Chem (HEMCO/GMI/v2015-02). Please contact
Sebastian Eastham (seastham@mit.edu) with any questions or to report any
issues about these files.

2x2.5 files were created in addition to the native resolution files for use
with older versions of MAPL/ESMF models (GCHP, GEOS) that put restrictions on
input file resolution relative to model resolution.

Further processing by the GEOS-Chem Support Team:
===============================================================================

NOTE: Bob Yantosca (yantosca@seas.harvard.edu) used the following bash
scripts to post-process the original data:

(1) WMO_2018/scripts/split_gmi_data_by_years.py

    - Splits the original GMI data files (which contained one file for all
      years 1959-2099) into one file per year with all species.

(2) WMO_2018/scripts/post_process_gmi_data.sh

    - Post-processes the GMI data files that were split by year for
      COARDS compliance.  Also chunks and compresses data, and edits
      file permissions.

(3) WMO_2006/scripts/split_ucx_data_by_years.py

    - Splits the original UCX data files (which contained one file for all
      years 1959-2099) into one file per year with all species.

(4) WMO_2006/scripts/post_process_ucx_data.sh

    - Post-processes the UCX data files that were split by year for
      COARDS compliance.  Also chunks and compresses data, and edits
      file permissions.

Please note that all files were also conservatively regridded by GCST to
2x2.5 resolution for use in GHCP. All 2x2.5 files are stored in a 2x2.5
subdirectory within WMO-2006 and WMO-2018 directories.

File List:
===============================================================================

surface_VMR_H2.nc

   - Surface concentration for H2 (time-invariant)

surface_VMR_OCS.nc

   - Surface concentration for OCS (time-invariant)

GMI/surface_VMRs_GMI_YYYY.nc  (YYYY = 1959..2099)

   - Surface concentrations for the following species from GMI:
     C2BR2F4, CBR2F2, CCl4, CFC113, CFC114, CFC115,   CFC11,    CFC12, CH3Br,
     CH3CCl3, CH3Cl,  CH4,  H1211m  H1301m  HCFC141bm HCFC142b, HCFC22

UCX/surface_VMRs_UCX_YYYY.nc  (YYYY = 1959..2099)

   - Surface concentrations for the following species from UCX:
     C2BR2F4, CBR2F2, CCl4, CFC113, CFC114, CFC115,   CFC11,    CFC12, CH3Br,
     CH3CCl3, CH3Cl,  CH4,  H1211m  H1301m  HCFC141bm HCFC142b, HCFC22


References:
===============================================================================

Eastham, S. D., Weisenstein, D. K., and Barrett, S. R. H.: Development and
valuation of the unified tropospheric– stratospheric chemistry extension (UCX)
for the global chemistry-transport model GEOS-Chem, Atmos. Environ., 89,
52–63, doi:10.1016/j.atmosenv.2014.02.001, 2014.