README

Author:      Daniel Neumann
Institution: Institute of Coastal Research, Helmholtz-Zentrum Geesthacht
Contact:     daniel.neumann@hzg.de
Version:     1.0
Date:        2015-10-29



~~~ CONTENT ~~~
  (1) Changes in the CMAQ Code
  (2) Changes in the Namelist files
  (3) Additions in the CMAQ Run Script
  (4) CMAQ Setup
~~~~~~~~~~~~~~~



~~~ (1) Changes in the CMAQ Code ~~~
The modules AERO_EMIS.F (minor changes) and SSEMIS.F were modified. All other 
modules were kept unchanged. Modifications in the modules and subroutines/
functions are documented in the beginning of each one by "[DATE] Neumann: ..." 
and indicated in the code by "NEUMANND". There are four types of in-code 
indications for modifications:

  1) long new code passages
    ! START NEUMANND
    [CODE]
    ! END NEUMANND

  2) new variables
    ! NEW VARIABLES BY NEUMANND
    [VARIABLE DEFINITION]

  3) individual new code lines 
    ! NEW NEUMANND: [DESCRIPTION]
    [CODE] ! NEW

  4) individual modified code lines
    ! MODIFIED NEUMANND: [DESCRIPTION]
    [CODE] ! 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



~~~ (2) Changes in the Namelist files ~~~
If I mode (Aitken mode) sea salt emissions are read in, they should be probably 
displayed in the output files as well. For this purpose the aerosol namelist 
file (AE_cb05tucl_ae5_aq.nml) should be modified. In the line starting with 
“ANAI”, the columns DDEP, WDEP and CONC should be set to “Yes”. Alternatively, 
one can replace the line 
    'ANAI:23.0:ANAI:1.0:VMASSI:1.0:NA_AITKEN:1.0:::NA_AITKEN:Yes:::',
with the line
    'ANAI:23.0:ANAI:1.0:VMASSI:1.0:NA_AITKEN:1.0:::NA_AITKEN:Yes:Yes:Yes:Yes',

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



~~~ (3) Additions in the CMAQ Run Script ~~~
Two new environment variables need to be set in the CMAQ run script in order
to read in sea salt emissions externally. Below, a code example is given:

  #> read sea-salt emissions from external file [ N|F ]
   setenv CTM_READSSEMIS Y

  #> Sea Salt emissions
   set SS_FILE = SSEMIS.${STDATE}  # example file name
   set SS_DIR  = /example/ssemis    # example directory name

  #> file containing the sea-salt emissions
   setenv SSEMIS_1 ${SS_DIR}/${SS_FILE}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



~~~ (4) CMAQ Setup ~~~
The 24 x 24 km2 and 72 x72 km2 grids are denoted as CD24 and CD72 grids and 
defined in the attached GRIDDESC file.

Six OCEAN files are attached – three for each grid. The identifier “sf050m” 
indicates that a surf zone of 50 m width is assumed. The identifier “_sal” 
indicates that the OPEN and SURF variables are scaled by the salinity as 
described in section 4.1. The identifier “_noSalt” indicates that OPEN and 
SURF are set to 0 (zero) so that no sea salt is emitted. The identifier 
“_GIS_ubound” indicates that the coastline data was extracted via ArcGIS 
according to Neumann et al. (2015) and that the SURF variable has an upper 
bound (Neumann et al., 2015). The table below indicates in which emission case 
which OCEAN file is used.


Employed Ocean Files (* = CD24|CD72)
 _______________________________________________________________________________
 CASE | OCEAN FILE                       | Description
 Zero | OCEAN_*_noSalt_GIS.nc            | OPEN=0 and SURF=0 => no sea salt emis
 GO03 | OCEAN_*_sf050m_GIS_ubound_sal.nc | ubound => threshold for SURF per cell
      |                                  | sal => salinity scaled
 OV14 | OCEAN_*_sf000m_GIS_ubound.nc     | ubound => threshold for SURF per cell
 SP13 | OCEAN_*_sf050m_GIS_ubound.nc     | ubound => threshold for SURF per cell
 -------------------------------------------------------------------------------

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