Original layer-to-space calculations were driven from the various namelists files and scripts in: /asl/s2/hannon/AIRS_prod08/CrIS/Run_trans_cris/. Breakout gases and mixed paths used are:

• all gases have weight 1.0, except H2O and O3 have weight 0.0 (F)
• all gases have weight 1.0 except H2O has weight 0.0 (FO)
• all gases have weight 1.0 (FOW)
• all gases have weight 1.0 except CO2 has weight 1.05 (FOWP)

Convolved kcarta L2S transmittances are at: /home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/REGR49_400ppm/F/
/home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/REGR49_400ppm/FO/
/home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/REGR49_400ppm/FWO/
/home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/REGR49_400ppm/FWOP/

Channel lists are at: ftc_dev/chanLists/list_crisSet1_hrg4 and list_crisSet2_hrg4.

Compiled ctrans data files at: /asl/s1/chepplew/projects/sarta/prod_2016/Prof400/Prof_FOW/

Breakout gases and mixed paths are:

• all gases have weight 1.0 except H2O and CH4 have weight 0.0 (F)
• all gases have weight 1.0 except H2O has weight 0.0 (FM)
• all gases have weight 1.0 (FMW)

Convolved kcarta L2S transmittances are at: /home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/REGR49_400ppm/ch4bandF/
/home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/REGR49_400ppm/ch4bandCH4/

Channel list is at: ftc_dev/chanLists/list_crisSet3_hrg4.

Compiled ctrans data files at: /asl/s1/chepplew/projects/sarta/prod_2016/Prof400/Prof_FMW/

Breakout gases and mixed paths are:

• all gases have weight 1.0 except H2O, CO, and O3 have weight 0.0 (F)
• all gases have weight 1.0 except H2O and O3 have weight 0.0 (FC)
• all gases have weight 1.0 except H2O has weight 0.0 (FCO)
• all gases have weight 1.0 (FCOW)
• all gases have weight 1.0 except CO2 has weight 1.05 (FCOWp)

Channel lists are at: ftc_dev/chanLists/list_crisSet4_hrg4, /list_crisSet5_hrg4, /list_crisSet6_hrg4 and /list_crisSet7_hrg4

Compile ctrans data files at: /asl/s1/chepplew/projects/sarta/prod_2016/Prof400/Prof_FWOsun/

For convenience a shell script is available at: ftc_dev/scripts/run_fitftc that operates on the regression files using the selected executable prescribed by the FITSET and DATATYPE variables.

There is an executable program for the regression of each of the 7 sets, that can be found in ftc_dev/Bin/fit_set{1-7}_*, where * refers to a code to help keep track of the type of predictors used in the fitting. The result is a set of coefficients for the break out gases for all channels, and the next step is to merge these with the water continuum coefficients (see next section). This produces a file with all channels included so the final step is to cut out the channels required, using the channel lists described above.

There is a separate merge and a separate cut program for each of the 7 sets of coefficients also found in /ftc_dev/Bin/merge_set{1-7} and cutlistcoef_set{1-7}, these are also written in Fortran.

Source: ftc_dev/fit_con/src_fitcon/
and: ftc_dev/fit_con/scripts/run_lbl_cris
Regression profiles: /home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/REGR49_400ppm/
regr49_1100_400ppm.op.rtp
with: refprof_truth_jul2000.mat or refprof_regr49_1100_400ppm.mat

A master script is used to drive the matlab template file: run_lbl.m, that runs the run8watercontinuum() line-by-line functions which is configured to use model CKD 6. There are other dependencies and child procs in the source directory. This produces a mat file at the native resolution of 0.25 wavenumber, over an extended spectral range, written to file: wcon8_ckd6_lbl_640_p25_2560.mat.

Source: ftc_dev/fit_con/scripts/run_fit
and: ftc_dev/fit_con/src_fitcon/fit_watercon.m
with: refprof_truth_jul2000.mat or refprof_regr49_1100_400ppm.mat

The bash script run_fit is used to control the matlab template file with the dependencies set accordingly. This produces a full resolution coefficient file: wcon8_ckd6_r49_rawcoef.dat, which must be interpolated on the CrIS spectral grid using the script: run_interp that can be run using the individual channel listings for each of the seven sets or once for the full CrIS channel list. Note that the continuum coefficients are smoothly varying with frequency so the interpolation method is robust. This produces 'mat' files according to the channel sets used. The option used here produces the complete channel set: wcon8_ckd6_r49_coef_cris_hrg4.dat.

The water continuum coefficients are then merged with the 7 breakout sets, see above.

The orignal fitting routine, ftc_dev/fit_therm/fittherm6cris.m gave unsatisfactory results, so although the current sarta program expects to load a thermal coefficient data file, these data are not used. Instead the calrad.f module has been changed to recompute the downward thermal flux and then the reflected component without the use of the F-factor approach originally adopted by Scott Hannon.

Sarta was built with the new calrad.f module and tested using kcarta generated data using regression sets:
regr_rtp_6angs_49profs_1013mb_seaemis_2235.rtp and
regr_rtp_6angs_49profs_1013mb_unitemis_2235.rtp
and TOA radiances:
/asl/s1/sergio/home/kcartaV118/WORK/RUN_TARA/GENERIC_RADSnJACS_MANYPROFILES/...
JUNK/xconvolved_kcarta_crisHI_xconvolved_kcarta_crisHI_1013mb_unitemiss.mat and \\ JUNK/xconvolved_kcarta_crisHI_xconvolved_kcarta_crisHI_1013mb_seaemiss.mat.
Results are shown in the figure

In the case where the native grid used by kcarta in the original L2S formulation, a set of coefficients and a version of sarta can be built to match them channel by channel. The file names have subscript kc.

In the case of CrIS with guard channels added at the ends of each of the three main spectral bands, and where these guard channels are incremented at the end of the channel list. So they take the highest channel numbers. A routine is used to convert the native set produced directly fro the kcarta work above and re-assign channel numbers:
ftc_dev/reorder_guard_chans.m

For the purposes of continuity to earlier versions of sarta and for use with other sensors, AIRS and IASI, the default file names are used, thus /Data_CrIS_sep16/Coef/set1.dat is the coefficient set for CrIS hi-res with 4 guard channels, and so forth.

The following three figures show the mean TOA brightness temperature spectra for the SARTA predictions compared to the kcarta calculations for the 49 regression profiles, with sea surface emissivity, used to evaluate the fast coefficients. In each plot the abscissa is wavenumber (cm-1) and the ordinate is the B.T. in Kelvin. The upper pane is the mean spectrum and the lower shows the mean bias and standard deviation of the difference. In the following set, calculations are made only at nadir. (see below for larger zenith view angles).

In each of the following graphics there are two panes. The upper pane is the kcarta result, and lower pane the new sarta result. In each case one of the minor gases from 6 of the original 49 regression profiles were perturbed by +10% over all altitudes. The result the mean difference due to the perturbed gas compared to the original unperturbed profile.

In each of the following plots the Jacobian (d(BT)/d(xG) where xG is the fractional change of the minor gas normalized to 1%. In the case of the profile plots, the minor gas is perturbed by 10% at each level alone from surface layer to TOA layer in turn. In the case of the spectal Jacobian the whole profile for the minor gas is perturbed by +10%.

1- Start with the individual kcarta L2S transmittance files (one for each regression profile) for each of the breakouts, 2- Compile these L2S files into new groups as required by the fitting code, using the matlab script doall_wrtconvdat_clh.dat (Ensure the I/O paths are set up correctly beforehand). 3- For the fixed gases, sets 1 thro' 7, optran water, variable CO2, use the fortran library of functions built from the source code in src_fitftc/ and support script in scripts/run_fitftc. Ensure I/O paths have been set up beforehand and update this script accordingly. 4- Do the fitting (see above) for sets 1 thro' 7 amd the water continuum, to produce raw coefficient files. 5- Merge the raw coefficient files for set1 thro' 7 with the water continuum using the functions built from source code in src_mergecut/. In each case ensure the included file: farra_<something>.f has been updated accordingly. 6- Cut out selected instrument channels from these 7 merged coefficient files using the functions built from source code in src_mergecut/. in each case ensure the included file: farray_<something>.f has been updated accordingly. 7- For CrIS using guard channels, these files of cut coefficients must re-ordered so that the default kcarta channel numbering is modified to correctly locate the guard channels at the highest numbered channels for SARTA. Use the matlab script reorder_guard_chans.m with paths and search terms updated accordingly.

Data: The SAF 704 regression profiles are selected by Sergio from the complete 25,000 profile set supplied by ECMWF. (SAF stands for satellite applications facility, see for example https://nwpsaf.eu/site/software/atmospheric-profile-data/ ). These profiles are then transposed on to the standard 100 layers used at ASL with the klayers routine and are stored at:
/home/sergio/MATLABCODE/REGR_PROFILES/ECMWF_SAF_137Profiles/save_SAF_704_profiles_29-Apr-2016_1100mb.op.rtp there are other versions depending on surface emissivity.

The layer-to-space (L2S) optical depths are computed using kcarta using a selection of different mixed gas paths (referred to as break-outs) and with specific boundary conditions, and for 12 viewing angles to produce the dependent variable onto which the predictors are to be fitted. The optical depths are convolved to the CrIS (or AIRS) spectral response functions, or instrumetn line shapes. These data are at:
/home/sergio/MATLABCODE/REGR_PROFILES/RUN_KCARTA/SAF704/F, FW, FWO, wvband*, so2band*, n2ohno3band*, and n2ohno3band.

For Scott's fitting code these convolved L2S data must be compiled into groups and reformatted to fortran binary files using the matlab routine doall_wrtconvdat_clh.m
This routine has been modified to accommodate the two different sets of regression profiles, the 49 set and the SAF704 set. These files are stored at:
/asl/s1/chepplew/data/sarta_wrk/prod_2016/p400/FMW, FWO, FWOp, with filenames starting with CRIS_SAF704_allPaths_.

Code: The fitting routines must be re-built with update parameters, for each farray_setX.f the maxmum profiles must be updated: PARAMETER(MAXPRO=703). Once the executable code is rebuilt and the correct input parameters are supplied the fitting code completes.
The merge with the water continuum and the cutting routines remain the same.

The line-by-line routine that runs the continuum model (scripts/run_lbl) on the SAF704 profiles, the fitting routine (scripts/run_fit) and the interpolation routine (scripts/run_interp) remain the same, but with the input and output paths updated accordingly.
RTPIN=/asl/s1/chepplew/projects/sarta/cris_hr/SAF704_regprofs_29apr2016_1100mb.op.rtp
and output files are written to:
/asl/s1/chepplew/data/sarta_wrk/cris_hr/Prof_LBL_water/SAF704_water*
and
/asl/s1/chepplew/data/sarta_wrk/cris_hr/wcon8_ckd6_saf704_lbl_640_p25_2670.mat

The fitting routine output is:
/asl/s1/chepplew/data/sarta_wrk/cris_hr/rawcoef_wcon8_ckd6_saf704_640_p25_2670.dat
and the output of the interpolation routine is:
/asl/s1/chepplew/data/sarta_wrk/cris_hr/interpcoef_wcon8_ckd6_saf704_cris_hrg4.dat

The optran fitting code is a part of the Fortran code set, and the include file: farray_optran_fmw.f must be updated with the number of atmospheric profiles used and the executable re-built. Since the FMW break-outs are used the compilation routine doall_wrtconvdat_clh.m must be run first on the L2S files. The coefficient data are written to:
ftc_dev/run/saf704/cris_hr/CrIS_hr_rawcoef_optran_fmw.dat

Do not forget to append the optran header to the coefficient file (see above).

The cutlistcoef_optran program remains unchanged, and the cut coefficient set is:
ftc_dev/run/saf704/cris_hr/CrIS_hr_cut_optran_fmw.dat