RTTOV Coefficient File Downloads

RTTOV v12 Coefficient File Downloads

The rttov_coef_download.sh script supplied in the RTTOV package in the rtcoef_rttov12/ directory can be used for downloading coefficient files in bulk or you can download individual files from the links below. You only need to download coefficients for the simulations you wish to carry out.

Update history for this page.

Additional information about coefficient files.

Spectral response functions and passbands used when generating the latest optical depth coefficient files.

Plots/tables comparing RTTOV with line-by-line (LBL) data for each optical depth coefficient file.


Notes on v11 compatibility

  • Optical depth (rtcoef) coefficient files – you can convert ASCII and HDF5 optical depth files between v10/v11-format and v12-format using the rttov11_conv_coef_11to12.exe and rttov11_conv_coef_12to11.exe executables which are built when you compile RTTOV. Note that NLTE coefficients are not transferred for hi-res IR sounders as the v11 and v12 NLTE models are mutually incompatible. For visible/IR files you will have to select the ISEM sea surface emissivity model if you convert v11 coefficients to v12 format.
  • Cloud and aerosol optical property (sccldcoef/scaercoef) files – these are mutually incompatible between v11 and v12.
  • RTTOV-SCATT Mietable files – these are identical for v11 and v12.
  • PC-RTTOV coefficient files – the format of PC-RTTOV files has not changed between v11 and v12 so you can use v11 PC-RTTOV coefficients with RTTOV v12 so long as you also use the corresponding v9 predictor optical depth coefficient file converted to v12 format. It is not recommended to use new v12 PC-RTTOV coefficient files (e.g. the new NLTE-compatible files) with v11 unless you know what you are doing.

Hi-res IR sounder optical depth coefficients

All hi-res IR sounder coefficient files share these characteristics:

  • Based on LBLRTM v12.2 line-by-line model
  • No Planck-weighted channels

Downloads

  • All files are linked in the table below.
  • Due to the large size of the hi-res sounder files HDF5 is the preferred format for them. Please contact the NWP SAF Helpdesk to request an ASCII version of a file if required. See here for notes on converting between coefficient file formats and extracting subsets of channels from coefficient files.
  • The same cloud and aerosol coefficient files are used with v7, v8 and v9 predictor optical depth coefficient files.
  • The chou-only cloud/aerosol files are recommended if you only want to use Chou-scaling for IR scattering simulations (no DOM, no solar) as the files are much smaller than the full ones.
  • Download to folders as follows:
    • v7 predictor 54L rtcoef files – download to rtcoef_rttov12/rttov7pred54L/
    • v7 predictor 101L rtcoef files – download to rtcoef_rttov12/rttov7pred101L/
    • v8 predictor 101L rtcoef files – download to rtcoef_rttov12/rttov8pred101L/
    • v9 predictor 101L rtcoef files – download to rtcoef_rttov12/rttov9pred101L/
    • All cloud/aerosol files – download to rtcoef_rttov12/cldaer_ir/

See below for information about cloud and aerosol optical property files.

SensorLevelsPredictors versionTrace gasesSolar?NLTE?FilenameDate of file creationAssociated cloud
coef filename
Associated OPAC aerosol
coef filename
Associated CAMS aerosol
coef filename
AIRS547O3NNrtcoef_eos_2_airs.H514/10/2016sccldcoef_eos_2_airs.H5
sccldcoef_eos_2_airs_chou-only.H5
scaercoef_eos_2_airs.H5
scaercoef_eos_2_airs_chou-only.H5
scaercoef_eos_2_airs_cams.H5
scaercoef_eos_2_airs_cams_chou-only.H5
AIRS1017O3NNrtcoef_eos_2_airs.H503/10/2016As aboveAs aboveAs above
AIRS1018O3, CO2NNrtcoef_eos_2_airs.H503/10/2016As aboveAs aboveAs above
AIRS1019O3, CO2, CO, N2O, CH4YNrtcoef_eos_2_airs.H503/11/2016As aboveAs aboveAs above
AIRS1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_eos_2_airs_so2.H521/11/2016As aboveAs aboveAs above
CrIS547O3NNrtcoef_jpss_0_cris.H514/10/2016sccldcoef_jpss_0_cris.H5
sccldcoef_jpss_0_cris_chou-only.H5
scaercoef_jpss_0_cris.H5
scaercoef_jpss_0_cris_chou-only.H5
scaercoef_jpss_0_cris_cams.H5
scaercoef_jpss_0_cris_cams_chou-only.H5
CrIS1017O3NNrtcoef_jpss_0_cris.H503/10/2016As aboveAs aboveAs above
CrIS1018O3, CO2NNrtcoef_jpss_0_cris.H503/10/2016As aboveAs aboveAs above
CrIS1019O3, CO2, CO, N2O, CH4YNrtcoef_jpss_0_cris.H503/11/2016As aboveAs aboveAs above
CrIS1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_jpss_0_cris_so2.H521/11/2016As aboveAs aboveAs above
CrIS FSR***547O3NNrtcoef_jpss_0_cris-fsr.H514/10/2016sccldcoef_jpss_0_cris-fsr.H5
sccldcoef_jpss_0_cris-fsr_chou-only.H5
scaercoef_jpss_0_cris-fsr.H5
scaercoef_jpss_0_cris-fsr_chou-only.H5
scaercoef_jpss_0_cris-fsr_cams.H5
scaercoef_jpss_0_cris-fsr_cams_chou-only.H5
CrIS FSR***1017O3NNrtcoef_jpss_0_cris-fsr.H503/10/2016As aboveAs aboveAs above
CrIS FSR***1018O3, CO2NNrtcoef_jpss_0_cris-fsr.H503/10/2016As aboveAs aboveAs above
CrIS FSR***1019O3, CO2, CO, N2O, CH4YNrtcoef_jpss_0_cris-fsr.H503/11/2016As aboveAs aboveAs above
CrIS FSR***1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_jpss_0_cris-fsr_so2.H521/11/2016As aboveAs aboveAs above
HIRAS547O3NNrtcoef_fy3_4_hiras.H511/12/2018sccldcoef_fy3_4_hiras.H5
sccldcoef_fy3_4_hiras_chou-only.H5
scaercoef_fy3_4_hiras.H5
scaercoef_fy3_4_hiras_chou-only.H5
scaercoef_fy3_4_hiras_cams.H5
scaercoef_fy3_4_hiras_cams_chou-only.H5
HIRAS1017O3NNrtcoef_fy3_4_hiras.H507/12/2018As aboveAs aboveAs above
HIRAS1018O3, CO2NNrtcoef_fy3_4_hiras.H511/12/2018As aboveAs aboveAs above
IASI547O3NYrtcoef_metop_2_iasi.H514/10/2016sccldcoef_metop_2_iasi.H5
sccldcoef_metop_2_iasi_chou-only.H5
scaercoef_metop_2_iasi.H5
scaercoef_metop_2_iasi_chou-only.H5
scaercoef_metop_2_iasi_cams.H5
scaercoef_metop_2_iasi_cams_chou-only.H5
IASI1017O3NYrtcoef_metop_2_iasi.H503/10/2016As aboveAs aboveAs above
IASI1018O3, CO2NYrtcoef_metop_2_iasi.H503/10/2016As aboveAs aboveAs above
IASI1019O3, CO2, CO, N2O, CH4YYrtcoef_metop_2_iasi.H505/12/2016As aboveAs aboveAs above
IASI1019O3, CO2, CO, N2O, CH4, SO2YYrtcoef_metop_2_iasi_so2.H517/03/2017As aboveAs aboveAs above
IASI-NG1017O3NNrtcoef_metopsg_1_iasing.H503/10/2016sccldcoef_metopsg_1_iasing.H5*
sccldcoef_metopsg_1_iasing_chou-only.H5*
scaercoef_metopsg_1_iasing.H5
scaercoef_metopsg_1_iasing_chou-only.H5
-
IASI-NG1018O3, CO2NNrtcoef_metopsg_1_iasing.H503/10/2016As aboveAs above-
IASI-NG1019O3, CO2, CO, N2O, CH4YNrtcoef_metopsg_1_iasing.H505/12/2016As aboveAs above-
IASI-NG1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_metopsg_1_iasing_so2.H517/03/2017As aboveAs above-
IKFS2547O3NNrtcoef_meteor-m_2_ikfs2.H514/10/2016---
IKFS21017O3NNrtcoef_meteor-m_2_ikfs2.H503/10/2016---
IKFS21018O3, CO2NNrtcoef_meteor-m_2_ikfs2.H503/10/2016---
IKFS21019O3, CO2, CO, N2O, CH4YNrtcoef_meteor-m_2_ikfs2.H503/11/2016---
IKFS21019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_meteor-m_2_ikfs2_so2.H521/11/2016---
IRIS1018O3, CO2NNrtcoef_nimbus_4_iris.H513/11/2016---
IRIS "shifted"**1018O3, CO2NNrtcoef_nimbus_4_iris-shifted.H523/02/2018---
MRFIRS547O3NNrtcoef_clarreo_1_mrfirs.H515/09/2017---
MRFIRS548O3, CO2NNrtcoef_clarreo_1_mrfirs.H515/09/2017---
SI1018O3, CO2NNrtcoef_meteor_25_si.H503/10/2016---

*Cloud optical property files (sccldcoef) marked with an asterisk do NOT include the new Deff cloud liquid water properties (currently only IASI-NG). If you require any cloud or aerosol file not linked in the table above please request this via the Helpdesk.

**Nimbus-4 IRIS “shifted” coefficients: nominal central wavenumbers are divided by 0.9995. This factor is mentioned in the literature (see the first paragraph under Methods on the last page).

***As of 5 September 2018 the CrIS-FSR instrument ID changed from 27 to 28 to distinguish it from CrIS nominal spectral resolution. The instrument ID in the coefficient file is not used by RTTOV when running simulations so there is no need to re-download the coefficient files (though the IDs have been updated in the files linked above). However the ID has changed in the latest version of the rttov_const.F90 module, and this is used by the rttov_read_coefs subroutine to construct the filename if you pass the (platform, satellite, instrument) ID triplet as an argument. Therefore if you read coefficients using the ID triplet, the instrument ID for CrIS-FSR is 27 in the RTTOV v12.2 release and earlier, but if you download the latest rttov_const.F90 (linked above) to src/main/ and recompile then the instrument ID is 28. The instrument ID will remain 28 in future releases of RTTOV.

Metop-B IASI coefficients

The Metop-B (i.e. metop_1) IASI optical depth coefficient file is identical to the Metop-A (metop_2) coefficient file except that the satellite ID is 1 (for Metop-B) instead of 2 (for Metop-A). The IASI cloud/aerosol scattering and PC coefficient files are identical for Metop-A and Metop-B.

NOAA-20 CrIS coefficients

The NOAA-20 CrIS and CrIS-FSR optical depth coefficient files are identical to the JPSS-0 (SNPP) files except for the different platform and satellite IDs so you can copy or create a link to the JPSS-0 file for NOAA-20 as required. The cloud/aerosol scattering files are identical for both platforms.

MTG-IRS coefficients

Experimental MTG-IRS coefficients have been generated using transmittances from simulated IASI spectra. The latest coefficients have been generated using the apodisation function described in the ATBD, 16 March 2018, integral of a Gaussian centred on “gate”, reference: MTG-IRS level 1 ATBD, EUM/RSP/TEN/16/878765, V1E draft 7 June 2017. This is a “light” apodisation similar to the previous “COSCAR” apodisation function and as such the errors in the RTTOV optical depth prediction scheme are larger than for other sensors, particularly in the short-wave band. For example see the following links for the LBL vs RTTOV statistics for each file (more information about these plots is available on the LBL/RTTOV comparison page):

The “v9 predictor” coefficients allow ozone as the only variable gas as for the “v7 predictor” coefficients, but have been trained for a wider range of zenith angles than the “v7 predictor” coefficients in common with other sensors. The “v9 predictor” files also enable solar radiation for affected channels.

Note that HTFRTC coefficients are available for MTG-IRS using the ATBD light apodisation function: radiances simulated using HTFRTC have much smaller errors than the “classical” RTTOV approach and as such HTFRTC is currently the recommended way to run clear-sky MTG-IRS simulations in RTTOV.

SensorLevelsPredictors versionTrace gasesNLTE?FilenameDate of file creationAssociated cloud coef filename
MTG-IRS apodisation from ATBD1017O3Nrtcoef_mtg_1_irs-atbd.H519/03/2018sccldcoef_mtg_1_irs.H5
sccldcoef_mtg_1_irs_chou-only.H5
MTG-IRS apodisation from ATBD1019O3Nrtcoef_mtg_1_irs-atbd.H519/03/2018As above

PC-RTTOV coefficients

Currently PC-RTTOV coefficients are available for a subset of hyperspectral IR sounders. It is important to use the same optical depth (rtcoef) coefficient file in the simulation as was used for training the PC coefficients. These files have “pcrttov_compat” in the filename and are linked in the table below. The optical depth coefficient files are all based on v9 predictors with all trace gases excluding SO2 and are on 101 levels.

The latest PC coefficients allow all optional RTTOV variable gases (except SO2). In addition new PC coefficients are available which allow for aerosol simulations using the OPAC aerosol optical properties. See the user guide for more information on this and see below for information on the PC regression limits for trace gases and aerosols.

The optical depth and PC coefficient files currently available are linked in the table below. The table also indicates what kind of simulations each set of PC coefficients is compatible with and this is also indicated in the pccoef filename:

  • sea => only trained for sea profiles: set calcemis(:) to TRUE
  • landsea => trained over all surface types: it is recommended to set calcemis(:) to TRUE over sea and to set calcemis(:) to FALSE over land and use the UW IR emissivity atlas to obtain land surface emissivity values (though this is not strictly mandatory)
  • nlte => can optionally be used with the RTTOV NLTE bias correction
  • trace => additional trace gases are optionally variable: O3, CO2, N2O, CO, CH4
  • aer => simulations can optionally include OPAC aerosols

See below for information on the gas and aerosol regression limits for PC-RTTOV.

The predictor channel selection is unique for each PC coefficient file and can be obtained in your own code using the rttov_get_pc_predictindex subroutine as demonstrated in src/test/example_pc_fwd.F90.

Downloads

  • All files are linked in the table below.
  • Due to the large size of the hi-res sounder files HDF5 is the preferred format for them. Please contact the NWP SAF Helpdesk to request an ASCII version of a file if required. See here for notes on converting between coefficient file formats and extracting subsets of channels from coefficient files.
  • Download to folders as follows:
    • PC-RTTOV-compatible v9 predictor 101L rtcoef files – download to rtcoef_rttov12/rttov9pred101L/
    • PC-RTTOV pccoef files – download to rtcoef_rttov12/pc/
    • OPAC Aerosol optical property scaercoef files – download to rtcoef_rttov12/cldaer_ir/
SensorTrace gases for PCNLTE
for PC?
Aerosols for PC?Surface types for PCOptical depth coef filenameDate of rtcoef file creationPC coef filenameAssociated OPAC aerosol
coef filename
AIRSO3NNland, seartcoef_eos_2_airs_pcrttov_compat.H501/02/2014pccoef_eos_2_airs_landsea.H5-
IASIO3, CO2, N2O, CO, CH4YNland, seartcoef_metop_2_iasi_pcrttov_compat.H502/09/2016pccoef_metop_2_iasi_landsea_trace_nlte.H5-
IASIO3, CO2, N2O, CO, CH4NYland, seaAs above02/09/2016pccoef_metop_2_iasi_landsea_trace_aer.H5scaercoef_metop_2_iasi_chou-only.H5
IASI-NGO3NNsea-onlyrtcoef_metopsg_1_iasing_pcrttov_compat.H501/02/2014pccoef_metopsg_1_iasing_sea.H5-

The Metop-2 (Metop-A) IASI files are identical to the Metop-1 (Metop-B) ones.


HTFRTC coefficients

HTFRTC coefficients are available for a number of hyperspectral IR sounders. Two files are required for HTFRTC simulations: the static coefficient file is required for all simulations and then a sensor-specific file is required for the instrument you wish to simulate. No other RTTOV coefficient files (e.g. rtcoef files) are required for HTFRTC simulations. See the user guide for more information about running HTFRTC simulations.

Downloads

  • All files are linked in the table below.
  • HTFRTC coefficient files are in NetCDF format.
  • Download required files to rtcoef_rttov12/htfrtc/
SensorTrace gasesHTFRTC coef filenameDate of file creation
Static file - required for all HTFRTC simulationsN/Ahtfrtc_coef_static.nc26/03/2018
AIRSO3 (mandatory)htfrtc_coef_sensor_eos_airs.nc26/03/2018
CrISO3 (mandatory)htfrtc_coef_sensor_jpss_cris.nc26/03/2018
CrIS-FSRO3 (mandatory)htfrtc_coef_sensor_jpss_cris_fsr.nc26/03/2018
IASIO3 (mandatory)htfrtc_coef_sensor_metop_iasi.nc26/03/2018
IASI-NGO3 (mandatory)htfrtc_coef_sensor_metopsg_iasing.nc26/03/2018
MTG-IRS*O3 (mandatory)htfrtc_coef_sensor_mtg_irs.nc26/03/2018

*MTG-IRS coefficients are for lightly apodised radiances. Apodisation function described in ATBD, 16 March 2018, integral of a Gaussian centred on “gate”, reference: MTG-IRS level 1 ATBD, EUM/RSP/TEN/16/878765, V1E draft 7 June 2017. HTFRTC can support any apodisation function: alternative/new HTFRTC coefficients for any hyperspectral IR sensor may be requested via the Helpdesk.

The IASI file is applicable to both Metop-A and Metop-B, and the CrIS and CrIS-FSR files are applicable to both JPSS-0 (SNPP) and NOAA-20.


IR optical depth coefficients

All IR coefficient files share these characteristics:

  • Based on LBLRTM v12.2 line-by-line model (except SSU which is based on LBLRTM v12.0)
  • 54 levels (except SSU on 51 levels and PMR on 84 levels)
  • Coefficients available based on v7 predictors allowing variable O3 and v8 predictors allowing variable O3 and CO2
  • Coefficients trained for zenith angles up to ~65 degrees, valid for zenith angles up to 75 degrees
  • Not solar compatible
  • Not NLTE compatible
  • Not PC compatible

For most instruments files are available for v7 predictors (variable O3) and v8 predictors (variable O3 and CO2). The CO2 concentration used to generate the v7 predictor files is contemporary (~400ppm) so for simulations of historical atmospheric profiles the v8 predictor files may be preferable as they allow you to specify a more appropriate CO2 profile.

Downloads

See below for information about cloud and aerosol optical property files.

SensorPredictors versionTrace gasesFilenameDate of file creationAssociated cloud coef filenameAssociated OPAC aerosol coef filenameAssociated CAMS aerosol coef filename
(A)ATSR*7 / 8O3 / O3, CO2rtcoef_ers_x_atsr.dat
rtcoef_envisat_1_atsr.dat
05/10/2016
10/11/2016
sccldcoef_ers_x_atsr.dat
sccldcoef_envisat_1_atsr.dat
scaercoef_ers_x_atsr.dat
scaercoef_envisat_1_atsr.dat
scaercoef_ers_x_atsr_cams.dat
scaercoef_envisat_1_atsr_cams.dat
AATSR-shifted
Info on AATSR 12 um anomaly
7 / 8O3 / O3, CO2rtcoef_envisat_1_atsr-shifted.dat05/10/2016
10/11/2016
sccldcoef_envisat_1_atsr-shifted.datscaercoef_envisat_1_atsr-shifted.datscaercoef_envisat_1_atsr-shifted_cams.dat
ABI7 / 8O3 / O3, CO2rtcoef_goes_xx_abi.dat05/10/2016
10/11/2016
sccldcoef_goes_xx_abi.datscaercoef_goes_xx_abi.datscaercoef_goes_xx_abi_cams.dat
AGRI7 / 8O3 / O3, CO2rtcoef_fy4_1_agri.dat24/05/2018sccldcoef_fy4_1_agri.datscaercoef_fy4_1_agri.datscaercoef_fy4_1_agri_cams.dat
AHI7 / 8O3 / O3, CO2rtcoef_himawari_x_ahi.dat05/10/2016
10/11/2016
sccldcoef_himawari_x_ahi.datscaercoef_himawari_x_ahi.datscaercoef_himawari_x_ahi_cams.dat
AMI7 / 8O3 / O3, CO2rtcoef_gkompsat2_1_ami.dat07/07/2017sccldcoef_gkompsat2_1_ami.datscaercoef_gkompsat2_1_ami.datscaercoef_gkompsat2_1_ami_cams.dat
ASTER7 / 8O3 / O3, CO2rtcoef_eos_1_aster.dat05/10/2016
10/11/2016
sccldcoef_eos_1_aster.datscaercoef_eos_1_aster.datscaercoef_eos_1_aster_cams.dat
AVHRR7 / 8O3 / O3, CO2rtcoef_noaa_xx_avhrr.dat
rtcoef_metop_x_avhrr.dat
05/10/2016
10/11/2016

13/11/2018
scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
scaercoef_noaa_xx_avhrr_cams.dat
scaercoef_metop_x_avhrr_cams.dat
ECOSTRESS7 / 8O3 / O3, CO2rtcoef_iss_1_ecostres.dat10/08/2018sccldcoef_iss_1_ecostres.datscaercoef_iss_1_ecostres.datscaercoef_iss_1_ecostres_cams.dat
FCI7 / 8O3 / O3, CO2rtcoef_mtg_1_fci.dat04/01/2017sccldcoef_mtg_1_fci.datscaercoef_mtg_1_fci.datscaercoef_mtg_1_fci_cams.dat
GMS imager7 / 8O3 / O3, CO2rtcoef_gms_x_imager.dat01/03/2017
02/03/2017
sccldcoef_gms_x_imager.datscaercoef_gms_x_imager.datscaercoef_gms_x_imager_cams.dat
GOES imager7 / 8O3 / O3, CO2rtcoef_goes_xx_imager.dat05/10/2016
10/11/2016
sccldcoef_goes_xx_imager.datscaercoef_goes_xx_imager.datscaercoef_goes_xx_imager_cams.dat
GOES sounder7 / 8O3 / O3, CO2rtcoef_goes_xx_sounder.dat05/10/2016
10/11/2016
sccldcoef_goes_xx_sounder.datscaercoef_goes_xx_sounder.datscaercoef_goes_xx_sounder_cams.dat
HIRS7 / 8O3 / O3, CO2rtcoef_noaa_xx_hirs.dat
rtcoef_metop_x_hirs.dat
rtcoef_nimbus_6_hirs.dat
05/10/2016
10/11/2016
sccldcoef_noaa_xx_hirs.dat
sccldcoef_metop_x_hirs.dat
sccldcoef_nimbus_6_hirs.dat
scaercoef_noaa_xx_hirs.dat
scaercoef_metop_x_hirs.dat
scaercoef_nimbus_6_hirs.dat
scaercoef_noaa_xx_hirs_cams.dat
scaercoef_metop_x_hirs_cams.dat
scaercoef_nimbus_6_hirs_cams.dat
HIRS shifted
spectral response
7 / 8O3 / O3, CO2rtcoef_noaa_xx_hirs-shifted.dat
rtcoef_metop_x_hirs-shifted.dat
17/10/2017
17/05/2017
sccldcoef_noaa_xx_hirs-shifted.dat
sccldcoef_metop_x_hirs-shifted.dat
scaercoef_noaa_xx_hirs-shifted.dat
scaercoef_metop_x_hirs-shifted.dat
scaercoef_noaa_xx_hirs-shifted_cams.dat
scaercoef_metop_x_hirs-shifted_cams.dat
IIR7 / 8O3 / O3, CO2rtcoef_calipso_1_iir.dat05/10/2016
10/11/2016
sccldcoef_calipso_1_iir.datscaercoef_calipso_1_iir.datscaercoef_calipso_1_iir_cams.dat
INSAT-3D(R) imager7 / 8O3 / O3, CO2rtcoef_insat3_x_imager.dat05/10/2016
10/11/2016
sccldcoef_insat3_x_imager.datscaercoef_insat3_x_imager.datscaercoef_insat3_x_imager_cams.dat
INSAT-3D(R) sounder7 / 8O3 / O3, CO2rtcoef_insat3_x_sounder.dat05/10/2016
10/11/2016
13/11/2016
sccldcoef_insat3_x_sounder.datscaercoef_insat3_x_sounder.datscaercoef_insat3_x_sounder_cams.dat
IRAS7 / 8O3 / O3, CO2rtcoef_fy3_1_iras.dat05/10/2016
10/11/2016
sccldcoef_fy3_1_iras.datscaercoef_fy3_1_iras.datscaercoef_fy3_1_iras_cams.dat
IRMSS7 / 8O3 / O3, CO2rtcoef_hj1_2_irmss.dat05/10/2016
10/11/2016
sccldcoef_hj1_2_irmss.datscaercoef_hj1_2_irmss.datscaercoef_hj1_2_irmss_cams.dat
MBFIRI7 / 8O3 / O3, CO2rtcoef_ticfire_1_mbfiri.dat15/09/2017sccldcoef_ticfire_1_mbfiri.datscaercoef_ticfire_1_mbfiri.datscaercoef_ticfire_1_mbfiri_cams.dat
MERSI-17 / 8O3 / O3, CO2rtcoef_fy3_3_mersi1.dat05/10/2016
10/11/2016
sccldcoef_fy3_3_mersi1.datscaercoef_fy3_3_mersi1.datscaercoef_fy3_3_mersi1_cams.dat
MERSI-27 / 8O3 / O3, CO2rtcoef_fy3_4_mersi2.dat23/11/2018sccldcoef_fy3_4_mersi2.datscaercoef_fy3_4_mersi2.datscaercoef_fy3_4_mersi2_cams.dat
MetImage7 / 8O3 / O3, CO2rtcoef_metopsg_1_metimage.dat05/10/2016
10/11/2016
sccldcoef_metopsg_1_metimage.datscaercoef_metopsg_1_metimage.datscaercoef_metopsg_1_metimage_cams.dat
MI7 / 8O3 / O3, CO2rtcoef_coms_1_mi.dat16/10/2017sccldcoef_coms_1_mi.datscaercoef_coms_1_mi.datscaercoef_coms_1_mi_cams.dat
MODIS7 / 8O3 / O3, CO2rtcoef_eos_x_modis.dat28/11/2016sccldcoef_eos_x_modis.datscaercoef_eos_x_modis.datscaercoef_eos_x_modis_cams.dat
MODIS shifted
spectral response
7 / 8O3 / O3, CO2rtcoef_eos_x_modis-shifted.dat28/11/2016sccldcoef_eos_x_modis-shifted.datscaercoef_eos_x_modis-shifted.datscaercoef_eos_x_modis-shifted_cams.dat
MRIR7 / 8O3 / O3, CO2rtcoef_nimbus_3_mrir.dat05/10/2016
10/11/2016
sccldcoef_nimbus_3_mrir.datscaercoef_nimbus_3_mrir.datscaercoef_nimbus_3_mrir_cams.dat
MSUMR7 / 8O3 / O3, CO2rtcoef_meteor-m_x_msumr.dat05/10/2016
10/11/2016

21/08/2018
sccldcoef_meteor-m_x_msumr.datscaercoef_meteor-m_x_msumr.datscaercoef_meteor-m_x_msumr_cams.dat
MTSAT imager7 / 8O3 / O3, CO2rtcoef_mtsat_x_imager.dat05/10/2016
10/11/2016
sccldcoef_mtsat_x_imager.datscaercoef_mtsat_x_imager.datscaercoef_mtsat_x_imager_cams.dat
MVIRI7 / 8O3 / O3, CO2rtcoef_meteosat_x_mviri.dat05/10/2016
10/11/2016
sccldcoef_meteosat_x_mviri.datscaercoef_meteosat_x_mviri.datscaercoef_meteosat_x_mviri_cams.dat
MVISR7 / 8O3 / O3, CO2rtcoef_fy1_x_mvisr.dat05/10/2016
10/11/2016
sccldcoef_fy1_x_mvisr.datscaercoef_fy1_x_mvisr.datscaercoef_fy1_x_mvisr_cams.dat
PMR** 84L8O3, CO2rtcoef_nimbus_6_pmr.dat15/12/2016---
SEVIRI7 / 8O3 / O3, CO2rtcoef_msg_x_seviri.dat05/10/2016
10/11/2016
sccldcoef_msg_x_seviri.datscaercoef_msg_x_seviri.datscaercoef_msg_x_seviri_cams.dat
SGLI7 / 8O3 / O3, CO2rtcoef_gcom-c_1_sgli.dat28/11/2016sccldcoef_gcom-c_1_sgli.datscaercoef_gcom-c_1_sgli.datscaercoef_gcom-c_1_sgli_cams.dat
SLSTR7 / 8O3 / O3, CO2rtcoef_sentinel3_x_slstr.dat05/10/2016
10/11/2016

11/07/2018
sccldcoef_sentinel3_x_slstr.datscaercoef_sentinel3_x_slstr.datscaercoef_sentinel3_x_slstr_cams.dat
SSU 51L8O3, CO2rtcoef_noaa_xx_ssu.dat02/08/2012
09/08/2012
29/08/2012
---
SSU 51L with variable
cell pressure
8O3, CO2rtcoef_noaa_xx_ssu_pmcshift.dat10/01/2013---
THIR7 / 8O3 / O3, CO2rtcoef_nimbus_x_thir.dat05/10/2016
10/11/2016
sccldcoef_nimbus_x_thir.datscaercoef_nimbus_x_thir.datscaercoef_nimbus_x_thir_cams.dat
TIRS7 / 8O3 / O3, CO2rtcoef_landsat_8_tirs.dat05/10/2016
10/11/2016
sccldcoef_landsat_8_tirs.datscaercoef_landsat_8_tirs.datscaercoef_landsat_8_tirs_cams.dat
TM7 / 8O3 / O3, CO2rtcoef_landsat_x_tm.dat05/10/2016
10/11/2016
sccldcoef_landsat_x_tm.datscaercoef_landsat_x_tm.datscaercoef_landsat_x_tm_cams.dat
VIIRS7 / 8O3 / O3, CO2rtcoef_jpss_0_viirs.dat
rtcoef_noaa_20_viirs.dat
05/10/2016
10/11/2016

25/10/2017
sccldcoef_jpss_0_viirs.dat
sccldcoef_noaa_20_viirs.dat
scaercoef_jpss_0_viirs.dat
scaercoef_noaa_20_viirs.dat
scaercoef_jpss_0_viirs_cams.dat
scaercoef_noaa_20_viirs_cams.dat
VIMS7 / 8O3 / O3, CO2rtcoef_gf5_1_vims.dat23/08/2017sccldoef_gf5_1_vims.datscaercoef_gf5_1_vims.datscaercoef_gf5_1_vims_cams.dat
VISSR7 / 8O3 / O3, CO2rtcoef_fy2_x_vissr.dat05/10/2016
10/11/2016

24/03/2017
sccldcoef_fy2_x_vissr.datscaercoef_fy2_x_vissr.datscaercoef_fy2_x_vissr_cams.dat
VTPR7 / 8O3 / O3, CO2rtcoef_noaa_x_vtpr1.dat05/10/2016
10/11/2016
---

* The ERS-1 ATSR coefficient file contains coefficients for 6 channels: 1-3 are the standard channels (12, 11, 3.7 microns respectively) and 4-6 are additional coefficients for the 12 micron channel using spectral responses valid at different sensor temperatures. The corresponding cloud and aerosol coefficients have been generated using this coefficient file and as such contain data for the 6 channels in the rtcoef file.

** PMR coefficients are a special case: the zenith angle must be set to zero as the zenith angle is part of each channel definition. The CO2 profiles used for training the PMR coefficients are different to those used for other coefficients: see the coefficient file for the reference (background) profile and the profile min/max envelope.

NB “NOAA-5” is TIROS-N.


Visible/IR solar-compatible optical depth coefficients

All visible/IR solar coefficient files share these characteristics:

  • Based on LBLRTM v12.2 line-by-line model
  • 54 levels
  • v9 predictors allowing variable O3 and CO2
  • Coefficients are trained for zenith angles up to ~85 degrees for solar-affected channels (wavelengths below 5 microns) and all channels on GEO sensors
  • Solar compatible
  • Not NLTE compatible
  • Not PC compatible
  • Note that you can run IR-only simulations using these files, but you may find the v7 or v8 predictor files above give better results for IR channels.
  • Channel numbering for IR channels may differ to the v7/v8 predictor files above: check the coefficient file headers, the user guide or the sensor tables page.

Downloads

See below for information about cloud and aerosol optical property files.

SensorTrace gasesFilenameDate of file creationAssociated cloud coef filenameAssociated OPAC aerosol coef filenameAssociated CAMS aerosol coef filename
(A)ATSR*O3, CO2rtcoef_ers_x_atsr.dat
rtcoef_envisat_1_atsr.dat
28/11/2016sccldcoef_ers_x_atsr.dat
sccldcoef_envisat_1_atsr.dat
scaercoef_ers_x_atsr.dat
scaercoef_envisat_1_atsr.dat
scaercoef_ers_x_atsr_cams.dat
scaercoef_envisat_1_atsr_cams.dat
AATSR-shifted
Info on AATSR 12 um anomaly
O3, CO2rtcoef_envisat_1_atsr-shifted.dat28/11/2016sccldcoef_envisat_1_atsr-shifted.datscaercoef_envisat_1_atsr-shifted.datscaercoef_envisat_1_atsr-shifted_cams.dat
ABIO3, CO2rtcoef_goes_xx_abi.dat28/11/2016sccldcoef_goes_xx_abi.datscaercoef_goes_xx_abi.datscaercoef_goes_xx_abi_cams.dat
AGRIO3, CO2rtcoef_fy4_1_agri.dat24/05/2018sccldcoef_fy4_1_agri.datscaercoef_fy4_1_agri.datscaercoef_fy4_1_agri_cams.dat
AHIO3, CO2rtcoef_himawari_x_ahi.dat28/11/2016sccldcoef_himawari_x_ahi.datscaercoef_himawari_x_ahi.datscaercoef_himawari_x_ahi_cams.dat
AMIO3, CO2rtcoef_gkompsat2_1_ami.dat07/07/2017sccldcoef_gkompsat2_1_ami.datscaercoef_gkompsat2_1_ami.datscaercoef_gkompsat2_1_ami_cams.dat
ASTERO3, CO2rtcoef_eos_1_aster.dat28/11/2016sccldcoef_eos_1_aster.datscaercoef_eos_1_aster.datscaercoef_eos_1_aster_cams.dat
AVHRRO3, CO2rtcoef_noaa_xx_avhrr.dat
rtcoef_metop_x_avhrr.dat
28/11/2016
13/11/2018
scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
scaercoef_noaa_xx_avhrr_cams.dat
scaercoef_metop_x_avhrr_cams.dat
FCIO3, CO2rtcoef_mtg_1_fci.dat04/01/2017sccldcoef_mtg_1_fci.datscaercoef_mtg_1_fci.datscaercoef_mtg_1_fci_cams.dat
GMS imagerO3, CO2rtcoef_gms_x_imager.dat02/03/2017sccldcoef_gms_x_imager.datscaercoef_gms_x_imager.datscaercoef_gms_x_imager_cams.dat
GOES imagerO3, CO2rtcoef_goes_xx_imager.dat28/11/2016sccldcoef_goes_xx_imager.datscaercoef_goes_xx_imager.datscaercoef_goes_xx_imager_cams.dat
INSAT-3D(R) imagerO3, CO2rtcoef_insat_x_imager.dat28/11/2016sccldcoef_insat_x_imager.datscaercoef_insat_x_imager.datscaercoef_insat_x_imager_cams.dat
IRASO3, CO2rtcoef_fy3_1_iras.dat28/11/2016sccldcoef_fy3_1_iras.datscaercoef_fy3_1_iras.datscaercoef_fy3_1_iras_cams.dat
LI**O3, CO2rtcoef_mtg_1_li.dat25/01/2017---
MERSI-2O3, CO2rtcoef_fy3_4_mersi2.dat23/11/2018sccldcoef_fy3_4_mersi2.datscaercoef_fy3_4_mersi2.datscaercoef_fy3_4_mersi2_cams.dat
MetImageO3, CO2rtcoef_metopsg_1_metimage.dat28/11/2016sccldcoef_metopsg_1_metimage.datscaercoef_metopsg_1_metimage.datscaercoef_metopsg_1_metimage_cams.dat
MIO3, CO2rtcoef_coms_1_mi.dat16/10/2017sccldcoef_coms_1_mi.datscaercoef_coms_1_mi.datscaercoef_coms_1_mi_cams.dat
MODISO3, CO2rtcoef_eos_x_modis.dat28/11/2016sccldcoef_eos_x_modis.datscaercoef_eos_x_modis.datscaercoef_eos_x_modis_cams.dat
MODIS shifted spectral responseO3, CO2rtcoef_eos_x_modis-shifted.dat28/11/2016sccldcoef_eos_x_modis-shifted.datscaercoef_eos_x_modis-shifted.datscaercoef_eos_x_modis-shifted_cams.dat
MSUMRO3, CO2rtcoef_meteor-m_2_msumr.dat27/08/2018sccldcoef_meteor-m_2_msumr.datscaercoef_meteor-m_2_msumr.datscaercoef_meteor-m_2_msumr_cams.dat
MTSAT imagerO3, CO2rtcoef_mtsat_x_imager.dat28/11/2016sccldcoef_mtsat_x_imager.datscaercoef_mtsat_x_imager.datscaercoef_mtsat_x_imager_cams.dat
OLCI***O3, CO2rtcoef_sentinel3_1_olci.dat06/01/2017---
OLIO3, CO2rtcoef_landsat_8_oli.dat28/11/2016sccldcoef_landsat_8_oli.datscaercoef_landsat_8_oli.datscaercoef_landsat_8_oli_cams.dat
SEVIRI****O3rtcoef_msg_x_seviri_o3.dat28/11/2016sccldcoef_msg_x_seviri.datscaercoef_msg_x_seviri.datscaercoef_msg_x_seviri_cams.dat
SEVIRIO3, CO2rtcoef_msg_x_seviri.dat28/11/2016As aboveAs aboveAs above
SLSTRO3, CO2rtcoef_sentinel3_x_slstr.dat28/11/2016
11/07/2018
sccldcoef_sentinel3_x_slstr.datscaercoef_sentinel3_x_slstr.datscaercoef_sentinel3_x_slstr_cams.dat
VIIRSO3, CO2rtcoef_jpss_0_viirs.dat
rtcoef_noaa_20_viirs.dat
28/11/2016
25/10/2017
sccldcoef_jpss_0_viirs.dat
sccldcoef_noaa_20_viirs.dat
scaercoef_jpss_0_viirs.dat
scaercoef_noaa_20_viirs.dat
scaercoef_jpss_0_viirs_cams.dat
scaercoef_noaa_20_viirs_cams.dat
VISSRO3, CO2rtcoef_fy2_x_vissr.dat28/11/2016sccldcoef_fy2_x_vissr.datscaercoef_fy2_x_vissr.datscaercoef_fy2_x_vissr_cams.dat

* The ERS-1 ATSR coefficient file contains coefficients for 7 channels: 1-4 are the standard channels (12, 11, 3.7, 1.6 microns respectively) and 5-7 are additional coefficients for the 12 micron channel using spectral responses valid at different sensor temperatures. The corresponding cloud and aerosol coefficients have been generated using this coefficient file and as such contain data for the 7 channels in the rtcoef file.

** The MTG LI file contains coefficients for two channels with SRFs corresponding to incidence angles of 0 and 5.1 degrees (channels 1 and 2 respectively).

*** The channel indexing in the OLCI coefficients is a special case: see the file headers for information on the channel indexing.

**** The variable O3+CO2 SEVIRI coefficients exhibit larger errors in reproducing the LBL data in channel 4 (3.9µm) so O3-only SEVIRI coefficients are also available.


MFASIS LUT files for visible cloud simulations

The MFASIS LUTs must be used alongside the visible/IR rtcoef and sccldcoef files listed in the table above. MFASIS LUTs are trained using either the OPAC cloud liquid water (CLW) properties or the “Deff” CLW properties. All LUTs are trained using the SSEC/Baum ice cloud optical properties. MFASIS simulations must specify the same clw_scheme and ice_scheme profile variables as used in training the LUT. See below for information about cloud liquid and ice water schemes. The executable rttov_mfasis_lut_info.exe prints out information about a given MFASIS LUT: see Annex A in the user guide for details.

NB MFASIS is only available in RTTOV v12.2 and later versions. RTTOV v12.2 users should download the MFASIS bug fix dated 30/10/2018 available on the bug fix/code updates page before using the LUT files below.

Downloads

  • All files are linked in the table below. LUT files for sensors not listed in the table can be requested via the NWP SAF Helpdesk.
  • MFASIS LUT files are in HDF5 format due to their large size. These can be read in alongside ASCII rtcoef and sccldcoef files.
  • MFASIS currently supports channels at wavelengths below 1 micron.
  • This document gives information on the errors in the MFASIS parameterisation by showing histograms of the differences between MFASIS and the multiple-scattering simulations used to train the LUTs.
  • Download required files to rtcoef_rttov12/mfasis_lut/

See below for information about cloud optical property files.

SensorAssociated rtcoef filenameAssociated cloud coef filenameMFASIS LUT file: OPAC CLWDate of OPAC CLW file creationMFASIS LUT file: Deff CLWDate of Deff CLW file creation
ABIrtcoef_goes_16_abi.dat
rtcoef_goes_17_abi.dat
sccldcoef_goes_16_abi.dat
sccldcoef_goes_17_abi.dat
rttov_mfasis_cld_goes_16_abi_opac.H5
rttov_mfasis_cld_goes_17_abi_opac.H5
07/10/2018
07/10/2018
rttov_mfasis_cld_goes_16_abi_deff.H5
rttov_mfasis_cld_goes_17_abi_deff.H5
11/10/2018
11/10/2018
AHIrtcoef_himawari_8_ahi.dat
rtcoef_himawari_9_ahi.dat
sccldcoef_himawari_8_ahi.dat
sccldcoef_himawari_9_ahi.dat
rttov_mfasis_cld_himawari_8_ahi_opac.H5
rttov_mfasis_cld_himawari_9_ahi_opac.H5
21/09/2018
25/09/2018
rttov_mfasis_cld_himawari_8_ahi_deff.H5
rttov_mfasis_cld_himawari_9_ahi_deff.H5
11/10/2018
11/10/2018
SEVIRIrtcoef_msg_3_seviri*.dat
rtcoef_msg_4_seviri*.dat
sccldcoef_msg_3_seviri.dat
sccldcoef_msg_4_seviri.dat
rttov_mfasis_cld_msg_3_seviri_opac.H5
rttov_mfasis_cld_msg_4_seviri_opac.H5
06/09/2018
12/09/2018
rttov_mfasis_cld_msg_3_seviri_deff.H5
rttov_mfasis_cld_msg_4_seviri_deff.H5
07/09/2018
27/09/2018

MW optical depth coefficients

All MW sensor coefficient files share these characteristics:

  • Based on Liebe 89/92 LbL model
  • All on 54 levels except for the Zeeman files
  • v7 predictors
  • No Planck-weighted channels
  • No optional trace gases
  • Cloud liquid water is an optional input for “clear-sky” (non-RTTOV-SCATT) simulations (treated as an absorbing medium)
  • Not solar compatible
  • Not NLTE compatible
  • Not PC compatible

Downloads

  • Files INCLUDING band-correction coefficients (recommended) – extract to rtcoef_rttov12/rttov7pred54L/, but note that this will OVERWRITE existing MW coefficient files in that directory. Band-correction coefficients are included for all sensors though in some cases they have very little impact. For those instruments where they have a significant impact on radiances, the impact of the band corrections on brightness temperatures is negligible.
  • Files for all MW sensors EXCLUDING band-correction coefficients – extract to rtcoef_rttov12/rttov7pred54L/, but note that this will OVERWRITE existing MW coefficient files in that directory.
  • RTTOV-SCATT Mietable files are linked in the table below – extract to rtcoef_rttov12/mietable/ (NB these were updated in April 2018 – see notes below)

Note: the optical property tables used by RTTOV-SCATT have historically been called “Mie tables”. This convention has become misleading as not all particles are treated as Mie spheres, in particular the optical properties for solid precipitation are based on non-spherical particles.

SensorZeeman
compatible
FilenameDate of rtcoef
file creation
Associated Mietable
filename
Date of Mietable
file creation
AltiKaNrtcoef_saral_1_altika.dat24/05/2017mietable_saral_altika.dat26/03/2018
AMRNrtcoef_jason_2_amr.dat24/05/2017-
AMSR-ENrtcoef_eos_2_amsre.dat24/05/2017mietable_eos_amsre.dat26/03/2018
AMSR2Nrtcoef_gcom-w_1_amsr2.dat24/05/2017mietable_gcom-w_amsr2.dat26/03/2018
AMSU-ANrtcoef_noaa_xx_amsua.dat
rtcoef_metop_x_amsua.dat
rtcoef_eos_2_amsua.dat
24/05/2017mietable_noaa_amsua.dat
mietable_metop_amsua.dat (rename/copy noaa file)
mietable_eos_amsua.dat (rename/copy noaa file)
26/03/2018
AMSU-BNrtcoef_noaa_xx_amsub.dat
24/05/2017mietable_noaa_amsub.dat
26/03/2018
ATMSNrtcoef_jpss_0_atms.dat
rtcoef_noaa_20_atms.dat
29/01/2018mietable_jpss_atms.dat
mietable_noaa_atms.dat (rename/copy jpss file)
26/03/2018
COWVRNrtcoef_ors_6_cowvr.dat24/05/2017-
CPRNrtcoef_cloudsat_1_cpr.dat09/05/2018-
DPRNrtcoef_gpm_1_dpr.dat27/09/2017-
GMINrtcoef_gpm_1_gmi.dat24/05/2017mietable_gpm_gmi.dat26/03/2018
HSBNrtcoef_eos_2_hsb.dat24/05/2017-
ICI*Nrtcoef_metopsg_1_ici.dat24/05/2017mietable_metopsg_ici.dat26/03/2018
MADRASNrtcoef_meghatr_1_madras.dat24/05/2017mietable_meghatr_madras.dat26/03/2018
MIRASNrtcoef_smos_1_miras.dat24/05/2017-
MHSNrtcoef_noaa_xx_mhs.dat
rtcoef_metop_x_mhs.dat
24/05/2017mietable_noaa_mhs.dat
mietable_metop_mhs.dat (rename/copy noaa file)
26/03/2018
MSUNrtcoef_noaa_xx_msu.dat24/05/2017-
MTVZA-GYNrtcoef_meteor-m_2_mtvzagy.dat24/05/2017-
MWHSNrtcoef_fy3_x_mwhs.dat24/05/2017mietable_fy3_mwhs.dat26/03/2018
MWHS2Nrtcoef_fy3_x_mwhs2.dat10/08/2018mietable_fy3_mwhs2.dat26/03/2018
MWINrtcoef_metopsg_1_mwi.dat24/05/2017mietable_metopsg_mwi.dat26/03/2018
MWRNrtcoef_ers_x_mwr.dat
rtcoef_envisat_1_mwr.dat
24/05/2017mietable_ers_mwr.dat
mietable_envisat_mwr.dat (rename/copy ers file)
26/03/2018
FY3 MWRINrtcoef_fy3_x_mwri.dat24/05/2017mietable_fy3_mwri.dat26/03/2018
HY2 MWRINrtcoef_hy2_1_mwri.dat17/04/2018-
MWSNrtcoef_metopsg_1_mws.dat24/05/2017mietable_metopsg_mws.dat26/03/2018
MWTSNrtcoef_fy3_x_mwts.dat24/05/2017mietable_fy3_mwts.dat26/03/2018
MWTS2Nrtcoef_fy3_x_mwts2.dat10/08/2018mietable_fy3_mwts2.dat26/03/2018
SAPHIRNrtcoef_meghatr_1_saphir.dat24/05/2017mietable_meghatr_saphir.dat26/03/2018
SCAMSNrtcoef_nimbus_6_scams.dat25/05/2017-
SMMRNrtcoef_nimbus_7_smmr.dat24/05/2017-
SSM/INrtcoef_dmsp_xx_ssmi.dat24/05/2017mietable_dmsp_ssmi.dat26/03/2018
SSMISNrtcoef_dmsp_xx_ssmis.dat24/05/2017mietable_dmsp_ssmis.dat26/03/2018
SSMIS Zeeman (84L)Yrtcoef_dmsp_xx_ssmis_zeeman.dat11/01/2017As above
SSM/T2Nrtcoef_dmsp_xx_ssmt2.dat24/05/2017-
TMINrtcoef_trmm_1_tmi.dat24/05/2017mietable_trmm_tmi.dat26/03/2018
TROPICSNrtcoef_tropics_0_tropics.dat24/10/2017mietable_tropics_tropics.dat26/03/2018
WindsatNrtcoef_coriolis_1_windsat.dat24/05/2017mietable_coriolis_windsat.dat26/03/2018

* ICI coefficients are preliminary: channel specifications may change. Work is planned to validate the spectroscopic data used at frequencies above 200GHz. The ICI mietable is generated in an identical manner to those for other instruments except as regards the scattering properties for snow particles. The ICI Mie table uses the Eriksson et al. (2018) sector snowflake (i.e. from the ARTS database) rather than the normal Liu (2008) version. This is because only the ARTS database has optical properties available at all ICI frequencies. Be aware that, at frequencies that are represented in both databases, there are small differences in the sector snowflake optical properties between the two databases. These differences are equivalent to several Kelvin in brightness temperature in deep convective areas.

NB “NOAA-5” is TIROS-N.

Updated Mie tables (April 2018)
Based on results from experiments carried out at ECMWF (Lonitz and Geer, 2018) the Mietable files have been updated using the Rosenkranz (2015) liquid water permittivity parameterisation which affects the cloud liquid water and rain hydrometeor types.

Note that these updated Mietable files will result in different output for the RTTOV-SCATT tests to the reference data provided in the RTTOV v12.2 package. Updated test reference data are available to download on the code updates page.

Updated Mie tables (September 2013)
The original RTTOV-SCATT Mie coefficients produced unrealistically high amounts of scattering from snow hydrometeors at 30-50 GHz and insufficient scattering at 150-183 GHz. The new coefficients address this problem by representing snow hydrometeors as three-dimensional snowflakes rather than Mie spheres. While it is possible to improve Mie sphere results by tuning the snow particle density, it is difficult to improve results at all frequencies simultaneously. The new snow hydrometeor optical properties are based on the “sector snowflake” from the Liu (2008) database of discrete dipole computations for nonspherical ice particles. The new particle shape was chosen because it produces the best fit between observations and ECMWF simulations across frequencies from 10 to 183 GHz.

References:

  • Eriksson, P., Ekelund, R., Mendrok, J., Brath, M., Lemke, O., and Buehler, S. A., 2018: A general database of hydrometeor single scattering properties at microwave and sub-millimetre wavelengths, Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2018-23, in review.
  • Geer, A.J. and F. Baordo, 2014: Improved scattering radiative transfer for frozen hydrometeors at microwave frequencies. Atmos. Meas. Tech., 7, 1839-1860, doi:10.5194/amt-7-1839-2014
  • Liu, G., 2008: A database of microwave single-scattering properties for nonspherical ice particles. Bulletin of the American Meteorological Society, 89(10), 1563-1570.
  • Lonitz, K. and Geer, A.J., 2018: Assessing the impact of different liquid water permittivity models on the fit between model and observations. Submitted to AMT.
  • Rosenkranz, P.W., 2015: A Model for the Complex Dielectric Constant of Supercooled Liquid Water at Microwave Frequencies. IEEE Trans. on Geosci. and Remote Sensing, 53, 3, 1387-1393.

Information on visible/IR cloud/aerosol files

Aerosol optical property files

Vertical profiles of layer aerosol concentrations are input to RTTOV in the profiles(:)%aerosols(1:naer,1:nlayers) array (see the user guide). Vertical profiles are provided for each of the aerosol types supported by the “scaercoef_*” aerosol property file being used from 1 to naer, the number of species in the aerosol file. There are two sets of aerosol property files available:

OPAC aerosol properties: these files contain optical properties for 13 species, most of which come from OPAC. Inputs to RTTOV should be dry aerosol mass ratio (kg/kg).

IndexShortnameHydrophilic?Description
1INSONOPAC insoluble (Hess et al 1998)
2WASOYOPAC water soluble
3SOOTNOPAC soot
4SSAMYOPAC sea salt accumulated mode
5SSCMYOPAC sea salt coarse mode
6MINMNOPAC mineral nucleation mode
7MIAMNOPAC mineral accumulation mode
8MICMNOPAC mineral coarse mode
9MITRNOPAC mineral transported
10SUSOYOPAC sulphated droplets
11VOLANVolcanic ash (Matricardi 2005)
12VAPONVolcanic ash based on measurements of Eyjafjallajökull eruption (RTTOV v11 SVR)
13ASDUNAsian dust: combination of the OPAC mineral nucc., acc. and coa. modes
based on fit to in-situ measurements (RTTOV v11 SVR)

References:

  • Hess, M., Kepke, P., and Schult, I., 1998: Optical Properties of Aerosols and Clouds: the software package OPAC. Bul. Am. Met. Soc., 79, pp. 831-844.
  • Matricardi, M., 2005: The inclusion of aerosols and clouds in RTIASI, the ECMWF fast radiative transfer model for the Infrared Atmospheric Sounding Interferometer. ECMWF Technical Memorandum 474
  • RTTOV v11 Science and Validation Report

CAMS aerosol properties: these files contain optical properties for 9 species consistent with the CAMS. Inputs to RTTOV should be dry aerosol mass ratio (kg/kg) except for the sea salt types which are mass ratios at 80% relative humidity: this is consistent with CAMS outputs.

IndexShort nameHydrophilic?Description
1BCARNHydrophobic black carbon, fixed refractive index at all wavelengths.
2DUS1NDust, bin 1, 0.03-0.55 micron, refractive index: Woodward 2001
3DUS2NDust, bin 2, 0.55-0.90 micron, refractive index: Woodward 2001
4DUS3NDust, bin 3, 0.90-20.0 micron, refractive index: Woodward 2001
5SULPYAmmonium sulphate
6SSA1YSea salt, bin 1, 0.03-0.5 micron
7SSA2YSea salt, bin 2, 0.50-5.0 micron
8SSA3YSea salt, bin 3, 5.0-20.0 micron
9OMATYHydrophilic organic matter

References:

  • Bozzo, A., Remy, S., Benedetti, A., Flemming, J., Bechtold, P., Rodwell, M.J., Morcrette, J.J., 2017: Implementation of a CAMS-based aerosol climatology in the IFS. ECMWF Technical Memorandum 801

Cloud optical property files

As of RTTOV v12.2 there are two options for predefined cloud liquid water (CLW) optical properties and two options for ice cloud optical properties. These are described in detail in the user guide. An overview is given here:

OPAC CLW scheme
These optical properties were introduced in RTTOV v9 and are based on five OPAC cloud types and vertical profiles of layer cloud concentrations are input to RTTOV in the profiles(:)%cloud(1:5,1:nlayers) array (see the user guide). The optical properties are computed from Mie theory. Each particle type has a fixed effective particle size: the particles differ in the assumed size distributions. Therefore the CLW effective diameter (profiles(:)%clwde(:)) is not used for these properties.

All sccldcoef files contain these optical properties. MFASIS LUT files are available trained with these optical properties.

Deff CLW scheme
These optical properties were introduced in RTTOV v12.2. They are based on the Mie properties available with libRadtran: in this case there is just one particle type and the optical properties are stored in terms of particle effective diameter. RTTOV sums the cloud concentrations provided in profiles(:)%cloud(1:5,lay) for each layer lay. Typically you would just specify the cloud concentration in one column, for example, profiles(:)%cloud(1,1:nlayers). For these properties the cloud effective diameter must be explicitly provided in the profiles(:)%clwde(1:nlayers) array.

All sccldcoef files contain these optical properties except for IASI-NG (if you require these properties for IASI-NG please request this via the NWP SAF Helpdesk). MFASIS LUT files are available trained with these optical properties.

SSEC/Baum ice scheme
These optical properties are stored in terms of ice effective diameter. Cloud concentrations are input to RTTOV in the profiles(:)%cloud(6,1:nlayers) array. RTTOV provides 4 parameterisations of ice effective diameter which are selected in the profiles(:)%idg variable. Alternatively you can specify the effective diameters explicitly in the profiles(:)%icede(1:nlayers) array. See the user guide for more details.

All sccldcoef files contain these optical properties. All MFASIS LUT files are trained with these optical properties.

Baran ice scheme
These optical properties are parameterised in terms of ice water content and temperature. Ice cloud concentrations are also input to RTTOV in the profiles(:)%cloud(6,1:nlayers) array, but there is no explicit dependence on effective diameter and so the idg and icede profile variables are ignored.

The data for this parameterisation are stored in the code rather than in external files. MFASIS is not currently compatible with this ice scheme.


Reference profiles and regression limits

RTTOV

RTTOV coefficients are trained using a set of diverse profiles which cover a wide range of values for each atmospheric variable. The latest coefficients are trained using diverse profiles which are designed to be applicable to the whole satellite era (1970-202x). H2O is the only gas for which profiles must always be supplied. The predictor version of the coefficient file determines which other gases may optionally be supplied:

  • v7 predictors: O3
  • v8 predictors: O3 and CO2
  • v9 predictors: O3, CO2, CO, N2O, CH4 and SO2

If no optional gas profile is supplied a fixed background profile is used. These fixed profiles are also used in training coefficients for which a particular gas cannot vary. The fixed profile concentrations are contemporary values: when simulating older instruments you may wish to use variable-CO2 coefficients so that you can supply more appropriate CO2 profiles. The fixed background profiles are contained in these comma-separated value files (gas units are ppmv with respect to dry air):

The diverse profile set also includes a selection of gases with fixed profiles in all training simulations (the “mixed gases”):

The fast optical depth calculations can be expected to be accurate for input profiles which lie within the profile “envelopes” defined by the minimum and maximum values for each profile variable on each level. By default RTTOV checks the input profile against a set of profile regression limits: it can warn if the regression limits are exceeded or, if the apply_reg_limits option is set to TRUE, clip the values to the limits where the limits are exceeded.

For some time it has been the practice in RTTOV to set the regression limits to +/-10% of the profile envelope for temperature and +/-20% of the profile envelope for each gas. For highly variable gases (such as water vapour) this stretching may be reasonable, but for less variable gases (such as CO2) the limits should probably be closer to the strict min/max envelope. It is planned to investigate and apply more appropriate stretches to the limits for each individual gas.

The comma-separated value files below show the stretched limits applied within RTTOV (gas units are ppmv with respect to dry air). Note that the RTTOV v12 coefficient files contain the strict profile min/max envelopes and the stretched profile limits applied within RTTOV are calculated when the coefficients are read in whereas RTTOV v11 (and earlier) coefficient files contain the stretched limits: despite this difference the behaviour of RTTOV v12 is the same as v11 in respect of the profile limits.

PC-RTTOV

As of RTTOV v12.2 PC-RTTOV coefficients are available which allow all variable trace gases (except SO2). PC-RTTOV is trained on a different set of profiles to the RTTOV optical depth coefficient files. The file linked below gives the minimum and maximum temperature and gas limits for PC-RTTOV coefficients.

PC-RTTOV coefficients for aerosol-affected simulations are also available. These are trained using profiles based on climatological combinations of the OPAC aerosol components. These PC coefficients must only be used with the OPAC aerosol files (the “Chou-only” files are recommended) and you should only specify non-zero concentrations for aerosol indices 1-10 (the components taken from OPAC). The minimum and maximum aerosol concentrations are given below in number density (cm^-3). Among the training profiles the aerosol concentrations did not vary for every type in every layer. Where the minimum and maximum limits are the same there was no variability and RTTOV automatically resets the aerosol concentrations to the values used in the training for those components/layers. Note that for the sulphates component (index 10) there was no variability at all among the training profiles so any input concentrations for sulphates will be overridden. If any regression limit is exceeded among the components/layers which varied in the training profiles, the qflag_pc_aer_reg_limits bit is set in radiance%quality(:) for the corresponding predictor channels. If the apply_reg_limits option is true, any values falling outside the limits are clipped to the respective minimum or maximum value just as for gases.