README -- Contents of lightning_NOx_200605/
31 Jan 2007
Bob Yantosca          and Philippe Le Sager
bmy@io.as.harvard.edu     phs@io.as.harvard.edu



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

light_dist.dat.geos1s: 

   PDF for lightning NOx by layer (Pickering et al 1998) -- ASCII format.
   Use this for GEOS-1, GEOS-STRAT met fields.


light_dist.dat.geos345.gcap: 

   The same data contained in the file "light_dist.dat.geos1s", but 
   interpolated onto onto a finer grid for use w/ GEOS-3, GEOS-4, GEOS-5, or 
   GCAP met fields. ASCII format.


OTD-LIS-Scale.CTH.v0.geos4.4x5: 

   File containing scale factors for lightning flash rates taken from OTD-LIS 
   satellite observations on the GEOS-Chem 4x5 grid.  BPCH format.
   %%% NOTE: THIS FILE IS OBSOLETE %%%


OTD-LIS-Regional-Redist.CTH.v1.geos4.4x5: 

   File containing monthly spatial redistribution factors (computed via
   the OTD-LIS regional method of Line Jourdain and as implemented by
   Lee Murray) for lightning flashes computed from OTD-LIS satellite 
   observations.  GEOS-Chem 4x5 grid.  BPCH format.
 

OTD-LIS-Local-Redist.CTH.v1.geos4.4x5: 

   File containing seasonal redistribution factors for lightning flashes  
   (computed via the OTD-LIS local redistribution method of Bastien Sauvage)
   for the GEOS-Chem 4x5 grid. BPCH format.


NOTE: Files may be gzipped, which adds the "*.gz" suffix.


Source:
===============================================================================
The light_dist* files are use to partition the column lightning NOx into 
GEOS-CHEM model layers.  These are taken from from the paper by 
Pickering et al. 1998, JGR 103, 31,203-31,316.  

Pickering computes 3 different PDF's, one for tropical midlatitude lightning,
one for tropical continental lightning, and one for midlatitude continental
lightning.

Mat Evans (mje@io.harvard.edu) had to interpolate the Pickering PDF's onto
a finer vertical resolution grid since the GEOS-3 layers near the surface
are much thinner than GEOS-1, GEOS-STRAT.  These PDF's may also be used with
the GEOS-4, GEOS-5, and GCAP meteorology.

The OTD-LIS-Regional-Redist* files were created by Lee Murray, using IDL code
that is stored within the ../IDL directory.  These files are used to make 
sure that the lightning flashes occur in the proper regions of the globe 
(i.e. corresponding where observed convection takes place).

The OTD-LIS-Local-Redist* files were created by Bob Yantosca with IDL routine 
~bmy/archive/data/lightning_NOx_200605/bastien/rf2bpch.pro.  This routine
reads text files provided by Bastien Sauvage (also in the bastien/ subdir) and
converts them to BPCH format.  The local redistribution is an alternative 
method to the OTD-LIS method.  Both methods can be selected as options in 
GEOS-Chem in order to ensure that lightning flashes occur where the observed
convection occurs.


Notes:
===============================================================================
(1) The light_dist.dat.* files are read into GEOS-Chem by the routine
     LIGHTDIST in "lightning_nox_nl_mod.f".

(2) The OTD-LIS-Regional-Redist.* files are read into GEOS-Chem by the routine
     READ_OTD_LIS_REDIST in "lightning_nox_nl_mod.f".

(3) The OTD-LIS-Local-Redist.* files are read into GEOS-Chem by the routine
     READ_LOCAL_REDIST in "lightning_nox_nl_mod.f".