README -- describes contents of /data/ctm/GEOS_MEAN/OHmerge/v5-07-08 09 Jan 2004 Bob Yantosca bmy@io.harvard.edu Files: ------ (1) OH_3Dglobal.geos1.2x25 -- 3-D OH fields for 2 x 2.5 GEOS-1 grid (2) OH_3Dglobal.geos1.4x5 -- 3-D OH fields for 4 x 5 GEOS-1 grid (3) OH_3Dglobal.geoss.2x25 -- 3-D OH fields for 2 x 2.5 GEOS-STRAT grid (4) OH_3Dglobal.geoss.4x5 -- 3-D OH fields for 4 x 5 GEOS-STRAT grid (5) OH_3Dglobal.geos3.2x25 -- 3-D OH fields for 2 x 2.5 GEOS-3 grid (6) OH_3Dglobal.geos3.4x5 -- 3-D OH fields for 4 x 5 GEOS-3 grid (7) OH_3Dglobal.geos4.2x25 -- 3-D OH fields for 2 x 2.5 GEOS-4 grid (8) OH_3Dglobal.geos4.4x5 -- 3-D OH fields for 4 x 5 GEOS-4 grid All files are binary punch format. Each file contains monthly mean data for a 1-year period for a given GEOS-CHEM grid. The data blocks are timestamped assuming year 1985, regardless of the actual year of the data. Source: ------- The monthly mean OH data was taken from the GEOS-CHEM v5-07-08 1-year benchmark run using GEOS-3 winds at 4 x 5 resolution for model year 2001. This run was submitted by Mat Evans and was completed in September 2003. The punch files from the v5-07-08 benchmark run are stored at Harvard at: (1) /data/ctm/GEOS_MEAN/2001/v5-07-08.mje/ctm.bpch.v5-07-08.Jan-Mar-2001 (2) /data/ctm/GEOS_MEAN/2001/v5-07-08.mje/ctm.bpch.v5-07-08.Apr-Jun-2001 (3) /data/ctm/GEOS_MEAN/2001/v5-07-08.mje/ctm.bpch.v5-07-08.Jul-Sep-2001 (4) /data/ctm/GEOS_MEAN/2001/v5-07-08.mje/ctm.bpch.v5-07-08.Oct-Dec-2001 Tropospheric OH data (computed by the SMVGEAR II solver) is stored in these punch files under GAMAP diagnostic category "CHEM-L=$" and tracer=1. The OH data is saved from levels 1-20, since the SMVGEAR II solver cannot operate in the stratosphere. Regridding Process: ------------------- (1) The 12 months of OH data (at GEOS-3, 4x5 grid) were saved into a separate file named "OH.geos3_20L.4x5". This was done by the following commands: gamap, 'CHEM-L=$', tracer=1, file='ctm.bpch.v5-07-08.Jan-Mar-2001' gamap, 'CHEM-L=$', tracer=1, file='ctm.bpch.v5-07-08.Apr-Jun-2001' gamap, 'CHEM-L=$', tracer=1, file='ctm.bpch.v5-07-08.Jul-Sep-2001' gamap, 'CHEM-L=$', tracer=1, file='ctm.bpch.v5-07-08.Oct-Dec-2001' gamap, 'CHEM-L=$', tracer=1, /NOFILE and then when GAMAP prompts you with: Enter S as first character to save data blocks. Select data records. Example: 1,3-9,20 (default : 1, Q=Quit, S=Save) >> type: s1-12 and then it will prompt you with a dialog box for the name of the output file into which the 12 data blocks will be saved. Type "OH.geos3_20L.4x5". (NOTE: you might want to save this file into a temporary directory in your own disk space, i.e. "~/temp/OH.geos3_20L.4x5".) (2) The "OH.geos3_20L.4x5" was combined with stratospheric OH data from the 2-D model of Dylan Jones and Hans Schneider by the IDL program ~bmy/IDL/regrid/merge_oh.pro. Change into the directory where the OH.geos3_20L.4x5 is found. Then you will have to edit the filenames FILE_T and FILE_Out in the CASE statement within the IDL code itself. After that, type: merge_oh, modelname='geos3', resolution=4 This will create an output file named "OH_3Dglobal.geos3.4x5", which contains merged (strat+trop) OH on the 4x5 GEOS-3 grid for 48 vertical levels. (3) The file "OH_3Dglobal.geos3.4x5" must then be vertically regridded from GEOS-3 to both GEOS-STRAT and GEOS-1 resolution. This is done by the IDL program ~bmy/IDL/regridv_3d_oh.pro. To invoke the program, type: ; regrid from GEOS-3 to GEOS-4 regridv_3d_oh, infilename='OH_3Dglobal.geos3.4x5', $ outfilename='OH_3Dglobal.geos4.4x5", $ outmodelname='geos4' ; regrid from GEOS-3 to GEOS-STRAT regridv_3d_oh, infilename='OH_3Dglobal.geos3.4x5', $ outfilename='OH_3Dglobal.geoss.4x5", $ outmodelname='geoss' ; regrid from GEOS-3 to GEOS-STRAT regridv_3d_oh, infilename='OH_3Dglobal.geos3.4x5', $ outfilename='OH_3Dglobal.geos1.4x5", $ outmodelname='geos1' This will create files "OH_3Dglobal.geoss.4x5" and "OH_3Dglobal.geos1.4x5", which contain merged (strat+trop) OH on the 4x5 GEOS-STRAT and GEOS-1 grids, respectively. (4) The 4 x 5 OH_3D* files must then be regridded to 2 x 2.5 resolution. This is done with IDL routine ~bmy/IDL/regrid/regridh_3d_oh.pro. To call this program, type: ; Regrid GEOS-4 4x5 to GEOS-4 2x2.5 regridh_3d_oh, infilename='OH_3Dglobal.geos4.4x5', $ outfilename='OH_3Dglobal.geos4.2x25',$ outresolution=2 ; Regrid GEOS-3 4x5 to GEOS-3 2x2.5 regridh_3d_oh, infilename='OH_3Dglobal.geos3.4x5', $ outfilename='OH_3Dglobal.geos3.2x25',$ outresolution=2 ; Regrid GEOS-STRAT 4x5 to GEOS-STRAT 2x2.5 regridh_3d_oh, infilename='OH_3Dglobal.geoss.4x5', $ outfilename='OH_3Dglobal.geoss.2x25',$ outresolution=2 ; Regrid GEOS-1 4x5 to GEOS-1 2x2.5 regridh_3d_oh, infilename='OH_3Dglobal.geos1.4x5', $ outfilename='OH_3Dglobal.geos1.2x25',$ outresolution=2 This will create files: OH_3Dglobal.geos4.2x25 OH_3Dglobal.geos3.2x25 OH_3Dglobal.geoss.2x25 OH_3Dglobal.geos1.2x25 which contain the merged (strat+trop) OH data at 2 x 2.5 horizontal resolution for the GEOS-3, GEOS-STRAT, and GEOS-1 grids, respectively. (5) In Summary: (a) Start w/ GEOS-3 4x5 tropospheric OH (b) Merge w/ strat OH from 2-D stratospheric model (c) Vertically regrid GEOS-3 4x5 to GEOS-4, GEOS-STRAT and GEOS-1 4x5 (d) Horizonally regrid all 4x5 to 2x2.5 Bob Yantosca bmy@io.harvard.edu 09 Jan 2004