RTTOV Coefficient File Downloads

RTTOV v13 Coefficient File Downloads

The rttov_coef_download.sh script supplied in the RTTOV package in the rtcoef_rttov13/ 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.


RTTOV v12 compatibility

  • New v13 predictor coefficient files are NOT compatible with RTTOV v12. Coefficients based on the new predictors are available for most sensors. These are the recommended optical depth coefficients for RTTOV v13. If you can’t find the file(s) you’re looking for below, you can request new coefficient files via the helpdesk.
  • All RTTOV v12-compatible rtcoef files can be used directly with RTTOV v13. Coefficient files trained with LBLRTM v12.8 and based on the old v7/8/9 predictors are available for most sensors: these can be used with RTTOV v12 and v13.
  • RTTOV v12 sccldcoef/scaercoef files do not work with RTTOV v13: new files for most sensors are available below (these cannot be used with v12). The cloud liquid water optical properties have been updated for v13 using a newer refractive index dataset.
  • New MFASIS LUT files have been generated for v13 based on the updated cloud liquid water properties: these include Rayleigh multiple scattering and improved flagging of out-of-bounds simulation geometry. The new files can be used with RTTOV v12, but note the caveats given below. The existing v12 MFASIS LUTs can also be used with v13, but the new files are strongly recommended in preference.
  • For RTTOV-SCATT, new hydrotables (v13 only) replace the old “Mietable” files (v12 and earlier only). The new files have updated optical properties.
  • RTTOV v12 PC-RTTOV coefficients files work with RTTOV v13.

Download pre-existing RTTOV v12 coefficients (v7/8/9 predictor VIS/IR coefficients based on LBLRTM v12.2 and v7 predictor MW coefficients) here.


Hi-res UV/VIS/IR sounder coefficients and optical properties

Optical depth coefs and cloud/aerosol optical properties

General information on hi-res IR sounder optical depth coefficient files:

  • Based on LBLRTM v12.8 line-by-line model
  • Based on v13 predictors
  • Coefficients on 101L with variable O3+CO2 available for all sensors
  • Coefficients on 54L and 101L with variable O3-only available for selected sensors (others on request)
  • Coefficients on 101L with all variable trace gases available for selected sensors (others on request)
  • Solar-enabled for channels below 5 microns
  • Coefficients for GEO sensors support the full range of zenith angles covered by RTTOV (up to ~85 degrees)
  • No Planck-weighted channels
  • For UV simulations RTTOV v13.1 and later are recommended

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 (ASCII, binary, HDF5) and extracting subsets of channels from coefficient files.
  • The same cloud and aerosol coefficient files are used with all optical depth coefficient files (including the old RTTOV v12-compatible rtcoef 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:
    • v13 predictor 101L rtcoef files – download to rtcoef_rttov13/rttov13pred101L/
    • v13 predictor 54L rtcoef files – download to rtcoef_rttov13/rttov13pred54L/
    • All cloud/aerosol files – download to rtcoef_rttov13/cldaer_visir/

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

SensorLevelsTrace gasesNLTE?FilenameDate of file creationAssociated cloud
coef filename
Associated OPAC aerosol
coef filename
Associated CAMS aerosol
coef filename
AIRS101O3, CO2Nrtcoef_eos_2_airs_o3co2.H530/10/2020sccldcoef_eos_2_airs.H5
sccldcoef_eos_2_airs_chou-only.H5
scaercoef_eos_2_airs_opac.H5
scaercoef_eos_2_airs_opac_chou-only.H5
scaercoef_eos_2_airs_cams.H5
scaercoef_eos_2_airs_cams_chou-only.H5
AIRS54O3Nrtcoef_eos_2_airs_o3.H526/10/2020As aboveAs aboveAs above
AIRS101O3Nrtcoef_eos_2_airs_o3.H526/10/2020As aboveAs aboveAs above
AIRS101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_eos_2_airs_7gas.H530/10/2020As aboveAs aboveAs above
CrIS NSR101O3, CO2Yrtcoef_jpss_0_cris_o3co2.H527/10/2020sccldcoef_jpss_0_cris.H5
sccldcoef_jpss_0_cris_chou-only.H5
scaercoef_jpss_0_cris_opac.H5
scaercoef_jpss_0_cris_opac_chou-only.H5
scaercoef_jpss_0_cris_cams.H5
scaercoef_jpss_0_cris_cams_chou-only.H5
CrIS NSR54O3Yrtcoef_jpss_0_cris_o3.H526/10/2020As aboveAs aboveAs above
CrIS NSR101O3Yrtcoef_jpss_0_cris_o3.H526/10/2020As aboveAs aboveAs above
CrIS NSR101O3, CO2, N2O, 
CO, CH4, SO2
Yrtcoef_jpss_0_cris_7gas.H529/10/2020As aboveAs aboveAs above
CrIS FSR101O3, CO2Yrtcoef_jpss_0_cris-fsr_o3co2.H527/10/2020sccldcoef_jpss_0_cris-fsr.H5
sccldcoef_jpss_0_cris-fsr_chou-only.H5
scaercoef_jpss_0_cris-fsr_opac.H5
scaercoef_jpss_0_cris-fsr_opac_chou-only.H5
scaercoef_jpss_0_cris-fsr_cams.H5
scaercoef_jpss_0_cris-fsr_cams_chou-only.H5
CrIS FSR54O3Yrtcoef_jpss_0_cris-fsr_o3.H526/10/2020As aboveAs aboveAs above
CrIS FSR101O3Yrtcoef_jpss_0_cris-fsr_o3.H526/10/2020As aboveAs aboveAs above
CrIS FSR101O3, CO2, N2O, 
CO, CH4, SO2
Yrtcoef_jpss_0_cris-fsr_7gas.H529/10/2020As aboveAs aboveAs above
FORUM101O3, CO2Nrtcoef_forum_1_forum_o3co2.H511/03/2021sccldcoef_forum_1_forum.H5
sccldcoef_forum_1_forum_chou-only.H5
--
FORUM101O3Nrtcoef_forum_1_forum_o3.H511/03/2021As above--
FORUM101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_forum_1_forum_7gas.H511/03/2021As above--
GIIRS**101O3, CO2Nrtcoef_fy4_1_giirs_o3co2.H528/10/2020sccldcoef_fy4_1_giirs.H5
sccldcoef_fy4_1_giirs_chou-only.H5
scaercoef_fy4_1_giirs_opac.H5
scaercoef_fy4_1_giirs_opac_chou-only.H5
scaercoef_fy4_1_giirs_cams.H5
scaercoef_fy4_1_giirs_cams_chou-only.H5
GIIRS**54O3Nrtcoef_fy4_1_giirs_o3.H526/10/2020As aboveAs aboveAs above
GIIRS**101O3Nrtcoef_fy4_1_giirs_o3.H526/10/2020As aboveAs aboveAs above
GIIRS**101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_fy4_1_giirs_7gas.H502/11/2020As aboveAs aboveAs above
GOME-2101O3Nrtcoef_metop_3_gome2_o3.H505/11/2021sccldcoef_metop_3_gome2.H5--
HIRAS NSR101O3, CO2Nrtcoef_fy3_4_hiras_o3co2.H527/10/2020sccldcoef_fy3_4_hiras.H5
sccldcoef_fy3_4_hiras_chou-only.H5
scaercoef_fy3_4_hiras_opac.H5
scaercoef_fy3_4_hiras_opac_chou-only.H5
scaercoef_fy3_4_hiras_cams.H5
scaercoef_fy3_4_hiras_cams_chou-only.H5
HIRAS NSR54O3Nrtcoef_fy3_4_hiras_o3.H529/10/2020As aboveAs aboveAs above
HIRAS NSR101O3Nrtcoef_fy3_4_hiras_o3.H527/10/2020As aboveAs aboveAs above
HIRAS NSR101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_fy3_4_hiras_7gas.H503/11/2020As aboveAs aboveAs above
HIRAS FSR101O3, CO2Nrtcoef_fy3_4_hirasfsr_o3co2.H528/10/2020sccldcoef_fy3_4_hirasfsr.H5
sccldcoef_fy3_4_hirasfsr_chou-only.H5
scaercoef_fy3_4_hirasfsr_opac.H5
scaercoef_fy3_4_hirasfsr_opac_chou-only.H5
scaercoef_fy3_4_hirasfsr_cams.H5
scaercoef_fy3_4_hirasfsr_cams_chou-only.H5
HIRAS FSR54O3Nrtcoef_fy3_4_hirasfsr_o3.H526/10/2020As aboveAs aboveAs above
HIRAS FSR101O3Nrtcoef_fy3_4_hirasfsr_o3.H526/10/2020As aboveAs aboveAs above
HIRAS FSR101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_fy3_4_hirasfsr_7gas.H502/11/2020As aboveAs aboveAs above
IASI101O3, CO2Yrtcoef_metop_2_iasi_o3co2.H530/10/2020sccldcoef_metop_2_iasi.H5
sccldcoef_metop_2_iasi_chou-only.H5
scaercoef_metop_2_iasi_opac.H5
scaercoef_metop_2_iasi_opac_chou-only.H5
scaercoef_metop_2_iasi_cams.H5
scaercoef_metop_2_iasi_cams_chou-only.H5
IASI54O3Yrtcoef_metop_2_iasi_o3.H526/10/2020As aboveAs aboveAs above
IASI101O3Yrtcoef_metop_2_iasi_o3.H526/10/2020As aboveAs aboveAs above
IASI101O3, CO2, N2O, 
CO, CH4, SO2
Yrtcoef_metop_2_iasi_7gas.H530/10/2020As aboveAs aboveAs above
IASI-NG101O3, CO2Nrtcoef_metopsg_1_iasing_o3co2.H528/10/2020sccldcoef_metopsg_1_iasing.H5
sccldcoef_metopsg_1_iasing_chou-only.H5
scaercoef_metopsg_1_iasing_opac.H5
scaercoef_metopsg_1_iasing_opac_chou-only.H5
scaercoef_metopsg_1_iasing_cams.H5
scaercoef_metopsg_1_iasing_cams_chou-only.H5
IASI-NG54O3Nrtcoef_metopsg_1_iasing_o3.H526/10/2020As aboveAs aboveAs above
IASI-NG101O3Nrtcoef_metopsg_1_iasing_o3.H527/10/2020As aboveAs aboveAs above
IASI-NG101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_metopsg_1_iasing_7gas.H529/10/2020As aboveAs aboveAs above
IKFS2101O3, CO2Nrtcoef_meteor-m_2_ikfs2_o3co2.H511/03/2021---
IKFS2101O3Nrtcoef_meteor-m_2_ikfs2_o3.H511/03/2021---
IKFS2101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_meteor-m_2_ikfs2_7gas.H511/03/2021---
IRIS101O3, CO2Nrtcoef_nimbus_4_iris_o3co2.H529/10/2020---
IRIS "shifted"*101O3, CO2Nrtcoef_nimbus_4_iris-shifted_o3co2.H529/10/2020---
IRIS "C3S"*101O3, CO2Nrtcoef_nimbus_4_iris-c3s_o3co2.H509/03/2021---
MTG IRS - Hamming apodised***101O3, CO2Nrtcoef_mtg_2_irs-hamming-2mopd_o3co2.H523/02/2021sccldcoef_mtg_2_irs.H5
sccldcoef_mtg_2_irs_chou-only.H5
scaercoef_mtg_2_irs_opac.H5
scaercoef_mtg_2_irs_opac_chou-only.H5
scaercoef_mtg_2_irs_cams.H5
scaercoef_mtg_2_irs_cams_chou-only.H5
MTG IRS - Hamming apodised***101O3Nrtcoef_mtg_2_irs-hamming-2mopd_o3.H523/02/2021As aboveAs aboveAs above
MTG IRS - Hamming apodised***101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_mtg_2_irs-hamming-2mopd_7gas.H523/02/2021As aboveAs aboveAs above
MTG IRS - lightly apodised***101O3, CO2Nrtcoef_mtg_2_irs-atbd-2mopd_o3co2.H529/10/2020As aboveAs aboveAs above
MTG IRS - lightly apodised***54O3Nrtcoef_mtg_2_irs-atbd-2mopd_o3.H526/10/2020As aboveAs aboveAs above
MTG IRS - lightly apodised***101O3Nrtcoef_mtg_2_irs-atbd-2mopd_o3.H526/10/2020As aboveAs aboveAs above
MTG IRS - lightly apodised***101O3, CO2, N2O, 
CO, CH4, SO2
Nrtcoef_mtg_2_irs-atbd-2mopd_7gas.H502/11/2020As aboveAs aboveAs above
MRFIRS54O3, CO2Nrtcoef_clarreo_1_mrfirs_o3co2.H530/10/2020---
SI101O3, CO2Nrtcoef_meteor_25_si_o3co2.H528/10/2020---

*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).
Nimbus-4 IRIS “C3S” coefficients were generated for the Copernicus Climate Change Service: more information is given in the headers which can be displayed using the rttov_coef_info.exe tool which is compiled to the bin/ directory as part of the RTTOV build.

**GIIRS coefficients were generated with the following channel configuration:
– Hamming apodisation (a=0.23, 0.8cm MPD)
– 1682 channels with spectral resolution = 0.625 cm-1
721 channels in band1 680-1130cm-1
961 channels in band2 1650-2250cm-1

***MTG-IRS coefficients: these have been generated using the latest channel specification which has different spectral resolutions in the long and short wave bands (hence “2mopd” in the filename to distinguish them from earlier files). The “hamming” files are based on Hamming-apodised transmittances, and are recommended for use with RTTOV. The “atbd” files are generated using the “light 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. Due to this light apodisation, 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 this page for the LBL vs RTTOV statistics for the RTTOV v13 predictor 101L variable O3+CO2 coefficients (more information about these plots is available on the LBL/RTTOV comparison page, with links to plots for all available MTG-IRS coefficients).

Metop-B/C IASI coefficients, NOAA-20 CrIS coefficients: the same coefficient files for a given hyperspectral sensor (including optical depth coefficients, cloud/aerosol properties, and PC coefficient files) can be used for that sensor on all satellite platforms. Therefore the IASI coefficient files for Metop-A can be used for Metop-B/C, and the CrIS NSR and FSR files for S-NPP (JPSS-0) can be used for NOAA-20.

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: these are currently all based on LBLRTM v12.2 and have not changed since RTTOV v12. 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 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_rttov13/rttov9pred101L/
    • PC-RTTOV pccoef files – download to rtcoef_rttov13/pc/
    • OPAC Aerosol optical property scaercoef files – download to rtcoef_rttov13/cldaer_visir/
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_opac_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 above can also be used for Metop-B and -C.

HTFRTC coefficients

There is a bug in HTFRTC in RTTOV v13 which means it cannot be used. HTFRTC coefficients will not be made available until the bug is fixed.

LBLRTM v12.8 RTTOV v7/8/9 predictor hyperspectral sounder coefficients

Various v7, v8 and v9 predictor hi-res IR sounder coefficients are available based on LBLRTM v12.8. These files can be used with RTTOV v12. If using RTTOV v13 we would encourage you to use the v13 predictor files above in preference to these. See the v13 predictor coefficients table above for links to the cloud/aerosol optical property files for these sensors, and see the notes below the v13 predictor table above for more information about the IRIS, GIIRS, MTG-IRS, IASI and CrIS coefficients.

SensorLevelsPredictors versionTrace gasesSolar?NLTE?FilenameDate of file creation
AIRS547O3NNrtcoef_eos_2_airs.H527/10/2020
AIRS1017O3NNrtcoef_eos_2_airs.H526/10/2020
AIRS1018O3, CO2NNrtcoef_eos_2_airs.H526/10/2020
AIRS1019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_eos_2_airs_7gas.H514/09/2020
CrIS NSR547O3NYrtcoef_jpss_0_cris.H526/10/2020
CrIS NSR1017O3NYrtcoef_jpss_0_cris.H526/10/2020
CrIS NSR1018O3, CO2NYrtcoef_jpss_0_cris.H526/10/2020
CrIS NSR1019O3, CO2, N2O, 
CO, CH4, SO2
YYrtcoef_jpss_0_cris_7gas.H514/09/2020
CrIS FSR547O3NYrtcoef_jpss_0_cris-fsr.H527/10/2020
CrIS FSR1017O3NYrtcoef_jpss_0_cris-fsr.H526/10/2020
CrIS FSR1018O3, CO2NYrtcoef_jpss_0_cris-fsr.H526/10/2020
CrIS FSR1019O3, CO2, N2O, 
CO, CH4, SO2
YYrtcoef_jpss_0_cris-fsr_7gas.H529/10/2020
FORUM1017O3NNrtcoef_forum_1_forum.H511/03/2021
FORUM1018O3, CO2NNrtcoef_forum_1_forum.H511/03/2021
FORUM1019O3, CO2, N2O, 
CO, CH4, SO2
NNrtcoef_forum_1_forum_7gas.H511/03/2021
GIIRS**547O3NNrtcoef_fy4_1_giirs.H527/10/2020
GIIRS**1017O3NNrtcoef_fy4_1_giirs.H527/10/2020
GIIRS**1018O3, CO2NNrtcoef_fy4_1_giirs.H527/10/2020
GIIRS**1019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_fy4_1_giirs_7gas.H502/11/2020
HIRAS NSR547O3NNrtcoef_fy3_4_hiras.H527/10/2020
HIRAS NSR1017O3NNrtcoef_fy3_4_hiras.H527/10/2020
HIRAS NSR1018O3, CO2NNrtcoef_fy3_4_hiras.H529/10/2020
HIRAS NSR1019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_fy3_4_hiras_7gas.H503/11/2020
HIRAS FSR547O3NNrtcoef_fy3_4_hirasfsr.H527/10/2020
HIRAS FSR1017O3NNrtcoef_fy3_4_hirasfsr.H527/10/2020
HIRAS FSR1018O3, CO2NNrtcoef_fy3_4_hirasfsr.H529/10/2020
HIRAS FSR1019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_fy3_4_hirasfsr_7gas.H502/11/2020
IASI547O3NYrtcoef_metop_2_iasi.H526/10/2020
IASI1017O3NYrtcoef_metop_2_iasi.H526/10/2020
IASI1018O3, CO2NYrtcoef_metop_2_iasi.H526/10/2020
IASI1019O3, CO2, N2O, 
CO, CH4, SO2
YYrtcoef_metop_2_iasi_7gas.H514/09/2020
IASI-NG547O3NNrtcoef_metopsg_1_iasing.H529/10/2020
IASI-NG1017O3NNrtcoef_metopsg_1_iasing.H526/10/2020
IASI-NG1018O3, CO2NNrtcoef_metopsg_1_iasing.H526/10/2020
IASI-NG1019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_metopsg_1_iasing_7gas.H529/10/2020
IKFS21017O3NNrtcoef_meteor-m_2_ikfs2.H511/03/2021
IKFS21018O3, CO2NNrtcoef_meteor-m_2_ikfs2.H511/03/2021
IKFS21019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_meteor-m_2_ikfs2_7gas.H511/03/2021
IRIS10113O3, CO2NNrtcoef_nimbus_4_iris.H527/10/2020
IRIS "shifted"*10113O3, CO2NNrtcoef_nimbus_4_iris-shifted.H529/10/2020
IRIS "C3S"*10113O3, CO2NNrtcoef_nimbus_4_iris-c3s.H509/03/2021
MTG-IRS Hamming apodised***1018O3, CO2NNrtcoef_mtg_2_irs-hamming-2mopd.H525/02/2021
MTG-IRS Hamming apodised***1019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_mtg_2_irs-hamming-2mopd_7gas.H511/02/2021
MTG-IRS lightly apodised***547O3NNrtcoef_mtg_2_irs-atbd-2mopd.H529/10/2020
MTG-IRS lightly apodised***1017O3NNrtcoef_mtg_2_irs-atbd-2mopd.H526/10/2020
MTG-IRS lightly apodised***1018O3, CO2NNrtcoef_mtg_2_irs-atbd-2mopd.H526/10/2020
MTG-IRS lightly apodised***1019O3, CO2, N2O, 
CO, CH4, SO2
YNrtcoef_mtg_2_irs-atbd-2mopd_7gas.H502/11/2020
MRFIRS547O3NNrtcoef_clarreo_1_mrfirs.H530/10/2020
MRFIRS548O3, CO2NNrtcoef_clarreo_1_mrfirs.H530/10/2020
SI1018O3, CO2NNrtcoef_meteor_25_si.H526/10/2020

UV/visible/IR coefficients and optical properties

UV/VIS/IR optical depth coefs and cloud/aerosol optical properties

General information on visible/IR optical depth coefficient files:

  • Based on LBLRTM v12.8 line-by-line model
  • Based on v13 predictors
  • Based on 54 levels
  • Coefficients with variable O3+CO2 for all sensors
  • Coefficients with variable O3-only for selected sensors (others on request)
  • Coefficients with all supported variable gases (“7gas”) for selected sensors (others on request)
  • Solar-enabled for channels below 5 microns: all files support all channels for which we have spectral response data
  • Coefficients for GEO sensors support the full range of zenith angles covered by RTTOV (up to ~85 degrees)
  • Not NLTE compatible
  • Not PC compatible
  • For UV simulations RTTOV v13.1 and later are recommended

NB Currently SSU, PMR coefficients are not available using v13 predictors: the RTTOV v12 files based on v8 predictors can be used with RTTOV v13. These can be downloaded below.

The CO2 concentration used to generate the variable O3-only files is contemporary (~400ppm) so for simulations of historical atmospheric profiles the variable O3+CO2 files are preferable as they allow you to specify a more appropriate CO2 profile.

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_o3co2.dat
rtcoef_envisat_1_atsr_o3co2.dat
16/10/2020sccldcoef_ers_x_atsr.dat
sccldcoef_envisat_1_atsr.dat
scaercoef_ers_x_atsr_opac.dat
scaercoef_envisat_1_atsr_opac.dat
scaercoef_ers_x_atsr_cams.dat
scaercoef_envisat_1_atsr_cams.dat
(A)ATSR*O3rtcoef_ers_x_atsr_o3.dat16/10/2020sccldcoef_ers_x_atsr.datscaercoef_ers_x_atsr_opac.datscaercoef_ers_x_atsr_cams.dat
AATSR-shifted
Info on AATSR 12 um anomaly
O3, CO2rtcoef_envisat_1_atsr-shifted_o3co2.dat16/10/2020sccldcoef_envisat_1_atsr-shifted.datscaercoef_envisat_1_atsr-shifted_opac.datscaercoef_envisat_1_atsr-shifted_cams.dat
AATSR-shifted
Info on AATSR 12 um anomaly
O3rtcoef_envisat_1_atsr-shifted_o3.dat16/10/2020As aboveAs aboveAs above
ABIO3, CO2rtcoef_goes_xx_abi_o3co2.dat16/10/2020sccldcoef_goes_xx_abi.datscaercoef_goes_xx_abi_opac.datscaercoef_goes_xx_abi_cams.dat
ABIO3rtcoef_goes_xx_abi_o3.dat16/10/2020As aboveAs aboveAs above
ABIO3, CO2, N2O, 
CO, CH4, SO2
rtcoef_goes_xx_abi_7gas.dat24/09/2020
25/09/2020
As aboveAs aboveAs above
AGRIO3, CO2rtcoef_fy4_1_agri_o3co2.dat16/10/2020sccldcoef_fy4_1_agri.datscaercoef_fy4_1_agri_opac.datscaercoef_fy4_1_agri_cams.dat
AGRIO3rtcoef_fy4_1_agri_o3.dat16/10/2020As aboveAs aboveAs above
AHIO3, CO2rtcoef_himawari_x_ahi_o3co2.dat16/10/2020sccldcoef_himawari_x_ahi.datscaercoef_himawari_x_ahi_opac.datscaercoef_himawari_x_ahi_cams.dat
AHIO3rtcoef_himawari_x_ahi_o3.dat16/10/2020As aboveAs aboveAs above
AHIO3, CO2, N2O, 
CO, CH4, SO2
rtcoef_himawari_x_ahi_7gas.dat24/09/2020As aboveAs aboveAs above
AMIO3, CO2rtcoef_gkompsat2_1_ami_o3co2.dat03/05/2021
sccldcoef_gkompsat2_1_ami.datscaercoef_gkompsat2_1_ami_opac.datscaercoef_gkompsat2_1_ami_cams.dat
AMIO3rtcoef_gkompsat2_1_ami_o3.dat29/04/2021As aboveAs aboveAs above
AMIO3, CO2, N2O, 
CO, CH4, SO2
rtcoef_gkompsat2_1_ami_7gas.dat03/05/2021As aboveAs aboveAs above
ASTERO3, CO2rtcoef_eos_1_aster_o3co2.dat16/10/2020sccldcoef_eos_1_aster.datscaercoef_eos_1_aster_opac.datscaercoef_eos_1_aster_cams.dat
ASTERO3rtcoef_eos_1_aster_o3.dat16/10/2020As aboveAs aboveAs above
AVHRRO3, CO2rtcoef_noaa_xx_avhrr_o3co2.dat
rtcoef_metop_x_avhrr_o3co2.dat
16/10/2020sccldcoef_noaa_xx_avhrr.dat
sccldcoef_metop_x_avhrr.dat
scaercoef_noaa_xx_avhrr_opac.dat
scaercoef_metop_x_avhrr_opac.dat
scaercoef_noaa_xx_avhrr_cams.dat
scaercoef_metop_x_avhrr_cams.dat
AVHRRO3rtcoef_noaa_xx_avhrr_o3.dat
rtcoef_metop_x_avhrr_o3.dat
16/10/2020As aboveAs aboveAs above
ECOSTRESSO3, CO2rtcoef_iss_1_ecostres_o3co2.dat28/10/2020sccldcoef_iss_1_ecostres.datscaercoef_iss_1_ecostres_opac.datscaercoef_iss_1_ecostres_cams.dat
EPICO3, CO2rtcoef_dscovr_1_epic_o3co2.dat30/10/2020sccldcoef_dscovr_1_epic.datscaercoef_dscovr_1_epic_opac.datscaercoef_dscovr_1_epic_cams.dat
EPICO3rtcoef_dscovr_1_epic_o3.dat30/10/2020As aboveAs aboveAs above
FCIO3, CO2rtcoef_mtg_1_fci_o3co2.dat16/10/2020sccldcoef_mtg_1_fci.datscaercoef_mtg_1_fci_opac.datscaercoef_mtg_1_fci_cams.dat
FCIO3rtcoef_mtg_1_fci_o3.dat16/10/2020As aboveAs aboveAs above
GMS imagerO3, CO2rtcoef_gms_x_imager_o3co2.dat16/10/2020sccldcoef_gms_x_imager.datscaercoef_gms_x_imager_opac.datscaercoef_gms_x_imager_cams.dat
GOES imagerO3, CO2rtcoef_goes_xx_imager_o3co2.dat16/10/2020sccldcoef_goes_xx_imager.datscaercoef_goes_xx_imager_opac.datscaercoef_goes_xx_imager_cams.dat
GOES imagerO3rtcoef_goes_xx_imager_o3.dat16/10/2020As aboveAs aboveAs above
GOES sounderO3, CO2rtcoef_goes_xx_sounder_o3co2.dat16/10/2020sccldcoef_goes_xx_sounder.datscaercoef_goes_xx_sounder_opac.datscaercoef_goes_xx_sounder_cams.dat
GOES sounderO3rtcoef_goes_xx_sounder_o3.dat16/10/2020As aboveAs aboveAs above
HIRSO3, CO2rtcoef_noaa_xx_hirs_o3co2.dat
rtcoef_metop_x_hirs_o3co2.dat
rtcoef_nimbus_6_hirs_o3co2.dat
16/10/2020sccldcoef_noaa_xx_hirs.dat
sccldcoef_metop_x_hirs.dat
sccldcoef_nimbus_6_hirs.dat
scaercoef_noaa_xx_hirs_opac.dat
scaercoef_metop_x_hirs_opac.dat
scaercoef_nimbus_6_hirs_opac.dat
scaercoef_noaa_xx_hirs_cams.dat
scaercoef_metop_x_hirs_cams.dat
scaercoef_nimbus_6_hirs_cams.dat
HIRSO3rtcoef_noaa_xx_hirs_o3.dat
rtcoef_metop_x_hirs_o3.dat
16/10/2020As aboveAs aboveAs above
HIRS shifted
spectral response
O3, CO2rtcoef_noaa_xx_hirs-shifted_o3co2.dat
rtcoef_metop_x_hirs-shifted_o3co2.dat
16/10/2020sccldcoef_noaa_xx_hirs-shifted.dat
sccldcoef_metop_x_hirs-shifted.dat
scaercoef_noaa_xx_hirs-shifted_opac.dat
scaercoef_metop_x_hirs-shifted_opac.dat
scaercoef_noaa_xx_hirs-shifted_cams.dat
scaercoef_metop_x_hirs-shifted_cams.dat
HIRS shifted
spectral response
O3rtcoef_noaa_xx_hirs-shifted_o3.dat
rtcoef_metop_x_hirs-shifted_o3.dat
16/10/2020sccldcoef_noaa_xx_hirs-shifted.dat
sccldcoef_metop_x_hirs-shifted.dat
scaercoef_noaa_xx_hirs-shifted_opac.dat
scaercoef_metop_x_hirs-shifted_opac.dat
scaercoef_noaa_xx_hirs-shifted_cams.dat
scaercoef_metop_x_hirs-shifted_cams.dat
HRIRO3, CO2rtcoef_nimbus_x_hrir_o3co2.dat16/10/2020sccldcoef_nimbus_x_hrir.datscaercoef_nimbus_x_hrir_opac.datscaercoef_nimbus_x_hrir_cams.dat
IIRO3, CO2rtcoef_calipso_1_iir_o3co2.dat16/10/2020sccldcoef_calipso_1_iir.datscaercoef_calipso_1_iir_opac.datscaercoef_calipso_1_iir_cams.dat
IIRO3rtcoef_calipso_1_iir_o3.dat16/10/2020As aboveAs aboveAs above
INSAT-3D(R) imagerO3, CO2rtcoef_insat3_x_imager_o3co2.dat16/10/2020sccldcoef_insat3_x_imager.datscaercoef_insat3_x_imager_opac.datscaercoef_insat3_x_imager_cams.dat
INSAT-3D(R) imagerO3rtcoef_insat3_x_imager_o3.dat16/10/2020As aboveAs aboveAs above
INSAT-3D(R) sounderO3, CO2rtcoef_insat3_x_sounder_o3co2.dat16/10/2020sccldcoef_insat3_x_sounder.datscaercoef_insat3_x_sounder_opac.datscaercoef_insat3_x_sounder_cams.dat
INSAT-3D(R) sounderO3rtcoef_insat3_x_sounder_o3.dat16/10/2020As aboveAs aboveAs above
IRASO3, CO2rtcoef_fy3_1_iras_o3co2.dat16/10/2020sccldcoef_fy3_1_iras.datscaercoef_fy3_1_iras_opac.datscaercoef_fy3_1_iras_cams.dat
IRMSSO3, CO2rtcoef_hj1_2_irmss_o3co2.dat27/10/2020sccldcoef_hj1_2_irmss.datscaercoef_hj1_2_irmss_opac.datscaercoef_hj1_2_irmss_cams.dat
LI**O3, CO2rtcoef_mtg_1_li_o3co2.dat16/10/2020---
LI**O3rtcoef_mtg_1_li_o3.dat16/10/2020---
MBFIRIO3, CO2rtcoef_ticfire_1_mbfiri_o3co2.dat16/10/2020sccldcoef_ticfire_1_mbfiri.datscaercoef_ticfire_1_mbfiri_opac.datscaercoef_ticfire_1_mbfiri_cams.dat
MBFIRIO3rtcoef_ticfire_1_mbfiri_o3.dat16/10/2020As aboveAs aboveAs above
MERSI-1O3, CO2rtcoef_fy3_3_mersi1_o3co2.dat27/10/2020sccldcoef_fy3_3_mersi1.datscaercoef_fy3_3_mersi1_opac.datscaercoef_fy3_3_mersi1_cams.dat
MERSI-2O3, CO2rtcoef_fy3_4_mersi2_o3co2.dat16/10/2020sccldcoef_fy3_4_mersi2.datscaercoef_fy3_4_mersi2_opac.datscaercoef_fy3_4_mersi2_cams.dat
MERSI-2O3rtcoef_fy3_4_mersi2_o3.dat16/10/2020As aboveAs aboveAs above
MetImageO3, CO2rtcoef_metopsg_1_metimage_o3co2.dat16/10/2020sccldcoef_metopsg_1_metimage.datscaercoef_metopsg_1_metimage_opac.datscaercoef_metopsg_1_metimage_cams.dat
MetImageO3rtcoef_metopsg_1_metimage_o3.dat16/10/2020As aboveAs aboveAs above
MIO3, CO2rtcoef_coms_1_mi_o3co2.dat16/10/2020sccldcoef_coms_1_mi.datscaercoef_coms_1_mi_opac.datscaercoef_coms_1_mi_cams.dat
MIO3rtcoef_coms_1_mi_o3.dat16/10/2020As aboveAs aboveAs above
MODISO3, CO2rtcoef_eos_x_modis_o3co2.dat16/10/2020sccldcoef_eos_x_modis.datscaercoef_eos_x_modis_opac.datscaercoef_eos_x_modis_cams.dat
MODISO3rtcoef_eos_x_modis_o3.dat16/10/2020As aboveAs aboveAs above
MODIS shifted spectral responseO3, CO2rtcoef_eos_x_modis-shifted_o3co2.dat16/10/2020sccldcoef_eos_x_modis-shifted.datscaercoef_eos_x_modis-shifted_opac.datscaercoef_eos_x_modis-shifted_cams.dat
MODIS shifted spectral responseO3rtcoef_eos_x_modis-shifted_o3.dat16/10/2020As aboveAs aboveAs above
MODIS shifted spectral responseO3, CO2, N2O, 
CO, CH4, SO2
rtcoef_eos_x_modis-shifted_7gas.dat25/09/2020As aboveAs aboveAs above
MRIRO3, CO2rtcoef_nimbus_x_mrir_o3co2.dat16/10/2020sccldcoef_nimbus_x_mrir.datscaercoef_nimbus_x_mrir_opac.datscaercoef_nimbus_x_mrir_cams.dat
MSIO3, CO2rtcoef_sentinel2_x_msi_o3co2.dat16/10/2020sccldcoef_sentinel2_x_msi.datscaercoef_sentinel2_x_msi_opac.datscaercoef_sentinel2_x_msi_cams.dat
MSIO3rtcoef_sentinel2_x_msi_o3.dat16/10/2020As aboveAs aboveAs above
MSUGSO3, CO2rtcoef_electro-l_2_msugs_o3co2.dat16/10/2020sccldcoef_electro-l_2_msugs.datscaercoef_electro-l_2_msugs_opac.datscaercoef_electro-l_2_msugs_cams.dat
MSUGSO3rtcoef_electro-l_2_msugs_o3.dat16/10/2020As aboveAs aboveAs above
MSUMRO3, CO2rtcoef_meteor-m_x_msumr_o3co2.dat16/10/2020sccldcoef_meteor-m_x_msumr.datscaercoef_meteor-m_x_msumr_opac.datscaercoef_meteor-m_x_msumr_cams.dat
MSUMRO3rtcoef_meteor-m_x_msumr_o3.dat16/10/2020As aboveAs aboveAs above
MTSAT imagerO3, CO2rtcoef_mtsat_x_imager_o3co2.dat29/10/2020
16/10/2020
sccldcoef_mtsat_x_imager.datscaercoef_mtsat_x_imager_opac.datscaercoef_mtsat_x_imager_cams.dat
MVIRI (IR channels only)O3, CO2rtcoef_meteosat_x_mviri_o3co2.dat16/10/2020sccldcoef_meteosat_x_mviri.datscaercoef_meteosat_x_mviri_opac.datscaercoef_meteosat_x_mviri_cams.dat
MVIRI-VIS****O3, CO2rtcoef_meteosat_x_mviri-vis_o3co2.dat31/05/2021
01/06/2021
02/06/2021
27/05/2021
---
MVISRO3, CO2rtcoef_fy1_x_mvisr_o3co2.dat16/10/2020sccldcoef_fy1_x_mvisr.datscaercoef_fy1_x_mvisr_opac.datscaercoef_fy1_x_mvisr_cams.dat
OLCI***O3, CO2rtcoef_sentinel3_x_olci_o3co2.dat16/10/2020sccldcoef_sentinel3_1_olci.dat
sccldcoef_sentinel3_2_olci.dat
--
OLCI***O3rtcoef_sentinel3_x_olci_o3.dat16/10/2020As above--
OLIO3, CO2rtcoef_landsat_8_oli_o3co2.dat16/10/2020sccldcoef_landsat_8_oli.datscaercoef_landsat_8_oli_opac.datscaercoef_landsat_8_oli_cams.dat
OLIO3rtcoef_landsat_8_oli_o3.dat16/10/2020As aboveAs aboveAs above
SBGO3, CO2rtcoef_sbg_1_sbg_o3co2.dat10/05/2021---
SBGO3rtcoef_sbg_1_sbg_o3.dat10/05/2021---
SEVIRIO3, CO2rtcoef_msg_x_seviri_o3co2.dat16/10/2020sccldcoef_msg_x_seviri.datscaercoef_msg_x_seviri_opac.datscaercoef_msg_x_seviri_cams.dat
SEVIRIO3rtcoef_msg_x_seviri_o3.dat16/10/2020As aboveAs aboveAs above
SEVIRIO3, CO2, N2O, 
CO, CH4, SO2
rtcoef_msg_x_seviri_7gas.dat24/09/2020As aboveAs aboveAs above
SGLIO3, CO2rtcoef_gcom-c_1_sgli_o3co2.dat16/10/2020sccldcoef_gcom-c_1_sgli.datscaercoef_gcom-c_1_sgli_opac.datscaercoef_gcom-c_1_sgli_cams.dat
SGLIO3rtcoef_gcom-c_1_sgli_o3.dat16/10/2020As aboveAs aboveAs above
SIRS / SIRS-BLURO3, CO2rtcoef_nimbus_x_sirs_o3co2.dat
rtcoef_nimbus_x_sirs-blur_o3co2.dat
16/10/2020sccldcoef_nimbus_x_sirs.dat
(same file for sirs-blur)
scaercoef_nimbus_x_sirs_opac.dat
(same file for sirs-blur)
scaercoef_nimbus_x_sirs_cams.dat
(same file for sirs-blur)
SLSTRO3, CO2rtcoef_sentinel3_x_slstr_o3co2.dat16/10/2020sccldcoef_sentinel3_x_slstr.datscaercoef_sentinel3_x_slstr_opac.datscaercoef_sentinel3_x_slstr_cams.dat
SLSTRO3rtcoef_sentinel3_x_slstr_o3.dat16/10/2020As aboveAs aboveAs above
SLSTRO3, CO2, N2O, 
CO, CH4, SO2
rtcoef_sentinel3_x_slstr_7gas.dat16/10/2020As aboveAs aboveAs above
THIRO3, CO2rtcoef_nimbus_x_thir_o3co2.dat16/10/2020sccldcoef_nimbus_x_thir.datscaercoef_nimbus_x_thir_opac.datscaercoef_nimbus_x_thir_cams.dat
TIRSO3, CO2rtcoef_landsat_8_tirs_o3co2.dat16/10/2020sccldcoef_landsat_8_tirs.datscaercoef_landsat_8_tirs_opac.datscaercoef_landsat_8_tirs_cams.dat
TIRSO3rtcoef_landsat_8_tirs_o3.dat16/10/2020As aboveAs aboveAs above
TMO3, CO2rtcoef_landsat_x_tm_o3co2.dat16/10/2020sccldcoef_landsat_x_tm.datscaercoef_landsat_x_tm_opac.datscaercoef_landsat_x_tm_cams.dat
TRISHNA-TIRO3, CO2rtcoef_trishna_1_tir_o3co2.dat06/05/2021sccldcoef_trishna_1_tir.datscaercoef_trishna_1_tir_opac.datscaercoef_trishna_1_tir_cams.dat
TRISHNA-TIRO3rtcoef_trishna_1_tir_o3.dat06/05/2021As aboveAs aboveAs above
TRISHNA-TIRO3, CO2, N2O, 
CO, CH4, SO2
rtcoef_trishna_1_tir_7gas.dat06/05/2021As aboveAs aboveAs above
VIIRSO3, CO2rtcoef_jpss_0_viirs_o3co2.dat
rtcoef_noaa_20_viirs_o3co2.dat
16/10/2020sccldcoef_jpss_0_viirs.dat
sccldcoef_noaa_20_viirs.dat
scaercoef_jpss_0_viirs_opac.dat
scaercoef_noaa_20_viirs_opac.dat
scaercoef_jpss_0_viirs_cams.dat
scaercoef_noaa_20_viirs_cams.dat
VIIRSO3rtcoef_jpss_0_viirs_o3.dat
rtcoef_noaa_20_viirs_o3.dat
16/10/2020As aboveAs aboveAs above
VIMSO3, CO2rtcoef_gf5_1_vims_o3co2.dat16/10/2020sccldcoef_gf5_1_vims.datscaercoef_gf5_1_vims_opac.datscaercoef_gf5_1_vims_cams.dat
VIMSO3rtcoef_gf5_1_vims_o3.dat16/10/2020As aboveAs aboveAs above
VIRRO3, CO2rtcoef_fy3_3_virr_o3co2.dat16/10/2020sccldcoef_fy3_3_virr.datscaercoef_fy3_3_virr_opac.datscaercoef_fy3_3_virr_cams.dat
VIRRO3rtcoef_fy3_3_virr_o3.dat16/10/2020As aboveAs aboveAs above
VISSRO3, CO2rtcoef_fy2_x_vissr_o3co2.dat16/10/2020
10/05/2021
sccldcoef_fy2_x_vissr.datscaercoef_fy2_x_vissr_opac.datscaercoef_fy2_x_vissr_cams.dat
VISSRO3rtcoef_fy2_x_vissr_o3.dat16/10/2020
10/05/2021
As aboveAs aboveAs above
VTPRO3, CO2rtcoef_noaa_x_vtpr1_o3co2.dat16/10/2020---

NB “NOAA-5” is TIROS-N.

* 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. Due to their size, the OLCI cloud optical property files are linked in the table above.

**** The MVIRI-VIS files contain coefficients for the MVIRI visible channel at 0.6 microns. As described in Quast et al (2019), the spectral response functions (SRFs) for this channel on each MVIRI platform have been changing over time, typically with more rapid change earlier in their lifetime than towards the end. The SRFs have been characterised at 45 day intervals throughout each satellite’s lifetime. Within each full year the SRFs were determined for the same days, starting at day 33 and ending at day 348. These MVIRI-VIS coefficient files contain one channel for each SRF for each platform and each file has a different number of channels since each platform had a different lifespan. The “README_SPECTRAL_RESPONSE_FUNCTION” section within each file provides the validity date of the first and last SRFs/channels in each file as YYYYDDD where YYYY is the year, and DDD is the day of the year. Users may wish to select the SRF/channel closest in time to that of their simulation. The contents of the files are summarised in this text file. An example Python function has been created which can be used to return the channel number corresponding to the SRF valid closest to the specified date for the specified Meteosat platform.

IR-only optical depth coefs and cloud/aerosol optical properties

The tarballs of coefficient files linked above contain files for all non-hyperspectral visible/IR sensors currently supported by RTTOV. In all cases, the files contain coefficients for all currently supported channels for each sensor. For sensors with both visible and IR channels you may want the optical depth coefficient and cloud/aerosol optical property files for just the IR channels. The tarballs below contain coefficients/properties for the IR channels only for those sensors.

You might want to use these files if you are replacing existing v7/v8 predictor rtcoef files (which support only IR channels) with equivalent v13 predictor coefficient files for sensors with VIS+IR channels.

You might want to use the cloud/aerosol optical property files if you are running scattering simulations using v7/v8 predictor rtcoef files for sensors with VIS+IR channels.

Note that you can extract subsets of channels (e.g. IR channels) from coefficient files using the tool described here.

MFASIS LUT files for visible cloud simulations

The MFASIS LUTs must be used alongside visible/IR rtcoef and sccldcoef files for the same sensor. MFASIS LUTs are trained using either the OPAC cloud liquid water (CLW) properties or the “Deff” CLW properties. All LUTs are trained using the 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.

For RTTOV v13 the MFASIS LUTs have been regenerated using the new Rayleigh multiple scattering capability in RTTOV and using the updated cloud liquid water optical properties. The new files also include additional information on the geometry used for training the LUTs which is enables improved quality flagging of out-of-bounds simulation geometries. The new files are recommended over previous v12 LUTs, but the old files can be used with RTTOV v13.

RTTOV v13.1 introduces support for 1.6 micron channels. New LUT files are available supporting this channel: these cannot be used with earlier versions of RTTOV. All pre-existing LUT files can be used with v13.1.

For relevant sensors/channels the LUTs take account of variable water vapour. Currently this only applies to the SEVIRI 0.8um channel.

This document gives some guidance on the accuracy of the MFASIS parameterisation vs the RTTOV-DOM training simulations.

The new v13 files (excluding those supporting 1.6 micron files) can be used with RTTOV v12 but note the following caveats:
1. Strictly speaking an MFASIS LUT file should be used with the same sccldcoef file used to generate the LUT. The new cloud liquid water optical properties are not available for RTTOV v12. However, the new optical properties do not differ greatly from the old properties available for RTTOV v12 at wavelengths below 1 micron and as such the new v13 MFASIS LUTs can be used with RTTOV v12 on the understanding that the simulation errors may be slightly larger. The benefits of the Rayleigh multiple scattering should outweigh this.
2. The improved quality flagging is not supported in v12. This may be important for some sensors (e.g. DSCOVR/EPIC) which have particular viewing geometries.

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 up to 1.6 micron.
  • Old MFASIS LUT files for channels at wavelengths below 1 micron (for use with RTTOV v13.0 and earlier) are indicated with “_sub1micron” in the filenames.
  • Download required files to rtcoef_rttov13/mfasis_lut/
SensorAssociated rtcoef filenameAssociated cloud coef filenameCompatible RTTOV versionsSupported channels (RTTOV channel numbers)MFASIS 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
v13.11,2,3,5rttov_mfasis_cld_goes_16_abi_opac.H5
rttov_mfasis_cld_goes_17_abi_opac.H5
16/09/2020
14/09/2020
rttov_mfasis_cld_goes_16_abi_deff.H5
rttov_mfasis_cld_goes_17_abi_deff.H5
06/09/2020
07/09/2020
ABIrtcoef_goes_16_abi*.dat
rtcoef_goes_17_abi*.dat
sccldcoef_goes_16_abi.dat
sccldcoef_goes_17_abi.dat
v13.1, v13.0, v12.31,2,3rttov_mfasis_cld_goes_16_abi_opac_sub1micron.H5
rttov_mfasis_cld_goes_17_abi_opac_sub1micron.H5
16/09/2020
14/09/2020
rttov_mfasis_cld_goes_16_abi_deff_sub1micron.H5
rttov_mfasis_cld_goes_17_abi_deff_sub1micron.H5
06/09/2020
07/09/2020
AHIrtcoef_himawari_8_ahi*.dat
rtcoef_himawari_9_ahi*.dat
sccldcoef_himawari_8_ahi.dat
sccldcoef_himawari_9_ahi.dat
v13.11,2,3,4,5rttov_mfasis_cld_himawari_8_ahi_opac.H5
rttov_mfasis_cld_himawari_9_ahi_opac.H5
13/09/2020
16/09/2020
rttov_mfasis_cld_himawari_8_ahi_deff.H5
rttov_mfasis_cld_himawari_9_ahi_deff.H5
04/09/2020
07/09/2020
AHIrtcoef_himawari_8_ahi*.dat
rtcoef_himawari_9_ahi*.dat
sccldcoef_himawari_8_ahi.dat
sccldcoef_himawari_9_ahi.dat
v13.1, v13.0, v12.31,2,3,4rttov_mfasis_cld_himawari_8_ahi_opac_sub1micron.H5
rttov_mfasis_cld_himawari_9_ahi_opac_sub1micron.H5
13/09/2020
16/09/2020
rttov_mfasis_cld_himawari_8_ahi_deff_sub1micron.H5
rttov_mfasis_cld_himawari_9_ahi_deff_sub1micron.H5
04/09/2020
07/09/2020
AMIrtcoef_gkompsat2_1_ami*.datsccldcoef_gkompsat2_1_ami.datv13.11,2,3,4,6rttov_mfasis_cld_gkompsat2_1_ami_opac.H525/08/21rttov_mfasis_cld_gkompsat2_1_ami_deff.H520/08/21
AMIrtcoef_gkompsat2_1_ami*.datsccldcoef_gkompsat2_1_ami.datv13.1, v13.0, v12.31,2,3,4rttov_mfasis_cld_gkompsat2_1_ami_opac_sub1micron.H525/08/21rttov_mfasis_cld_gkompsat2_1_ami_deff_sub1micron.H520/08/21
EPIC (see notes below)rtcoef_dscovr_1_epic*.datsccldcoef_dscovr_1_epic*.datv13.1, v13.0, v12.31,2,3,6rttov_mfasis_cld_dscovr_1_epic_opac.H509/12/2020rttov_mfasis_cld_dscovr_1_epic_deff.H506/12/2020
SEVIRI (includes WV correction)rtcoef_msg_1_seviri*.dat
rtcoef_msg_2_seviri*.dat
rtcoef_msg_3_seviri*.dat
rtcoef_msg_4_seviri*.dat
sccldcoef_msg_1_seviri.dat
sccldcoef_msg_2_seviri.dat
sccldcoef_msg_3_seviri.dat
sccldcoef_msg_4_seviri.dat
v13.11,2,3rttov_mfasis_cld_msg_1_seviri_opac.H5
rttov_mfasis_cld_msg_2_seviri_opac.H5
rttov_mfasis_cld_msg_3_seviri_opac.H5
rttov_mfasis_cld_msg_4_seviri_opac.H5
10/09/2020
12/09/2020
12/09/2020
10/09/2020
rttov_mfasis_cld_msg_1_seviri_deff.H5
rttov_mfasis_cld_msg_2_seviri_deff.H5
rttov_mfasis_cld_msg_3_seviri_deff.H5
rttov_mfasis_cld_msg_4_seviri_deff.H5
27/08/2020
21/08/2020
15/08/2020
10/08/2020
SEVIRI (includes WV correction)rtcoef_msg_1_seviri*.dat
rtcoef_msg_2_seviri*.dat
rtcoef_msg_3_seviri*.dat
rtcoef_msg_4_seviri*.dat
sccldcoef_msg_1_seviri.dat
sccldcoef_msg_2_seviri.dat
sccldcoef_msg_3_seviri.dat
sccldcoef_msg_4_seviri.dat
v13.1, v13.0, v12.31,2rttov_mfasis_cld_msg_1_seviri_opac_sub1micron.H5
rttov_mfasis_cld_msg_2_seviri_opac_sub1micron.H5
rttov_mfasis_cld_msg_3_seviri_opac_sub1micron.H5
rttov_mfasis_cld_msg_4_seviri_opac_sub1micron.H5
10/09/2020
12/09/2020
12/09/2020
10/09/2020
rttov_mfasis_cld_msg_1_seviri_deff_sub1micron.H5
rttov_mfasis_cld_msg_2_seviri_deff_sub1micron.H5
rttov_mfasis_cld_msg_3_seviri_deff_sub1micron.H5
rttov_mfasis_cld_msg_4_seviri_deff_sub1micron.H5
27/08/2020
21/08/2020
15/08/2020
10/08/2020

Notes:
EPIC
RTTOV currently only supports channels 5-10 of the EPIC sensor. In RTTOV these supported channels are numbered 1-6. The EPIC MFASIS LUTs support only channels 1, 2, 3 and 6 of these (5, 6, 7, and 10 in the instrument channel numbering): channels 4 and 5 (8 and 9, at 688nm and 764nm) are not currently simulated by MFASIS because the significant O2 absorption means that the amount of atmosphere between the sensor and the cloud must be accounted for, and this is not currently possible in MFASIS. In addition the EPIC LUTs are trained for a restricted set of scattering angles (4-14 degrees, where zero represents direct back-scatter) appropriate to the orbit of this sensor.

LBLRTM v12.8 RTTOV v7/8/9 predictor coefficients

v7/8/9 predictor VIS/IR sensor coefficients based on LBLRTM v12.8 are available for most sensors. We would encourage you to use the v13 predictor files above in preference to these with RTTOV v13. These files can be used with RTTOV v12. The SSU coefficients linked here have not been updated. The v8 predictor tarball includes the Nimbus-6 PMR coefficients which have not been updated.


MW optical depth coefs and RTTOV-SCATT optical properties

General information on MW sensor optical depth coefficient files:

  • Based on Liebe 89/92 LbL model
  • All on 54 levels
  • v13 predictors
  • No Planck-weighted channels
  • No optional trace gases except ICI which allows variable O3
  • Not solar compatible
  • Not NLTE compatible
  • Not PC compatible

Downloads

SensorFilenameDate of rtcoef
file creation
Associated hydrotable
filename
Date of hydrotable
file creation
Hydrotable
radar-enabled?
AltiKartcoef_saral_1_altika.dat26/02/2020hydrotable_saral_altika.dat23/09/2020N
AMRrtcoef_jason_2_amr.dat26/02/2020-
AMR-Crtcoef_jasoncs_1_amrc.dat26/02/2020-
AMSR-Ertcoef_eos_2_amsre.dat26/02/2020hydrotable_eos_amsre.dat23/09/2020N
AMSR2rtcoef_gcom-w_1_amsr2.dat26/02/2020hydrotable_gcom-w_amsr2.dat23/09/2020N
AMSU-Artcoef_noaa_xx_amsua.dat
rtcoef_metop_x_amsua.dat
rtcoef_eos_2_amsua.dat
26/02/2020hydrotable_noaa_amsua.dat
hydrotable_metop_amsua.dat (rename/copy noaa file)
hydrotable_eos_amsua.dat (rename/copy noaa file)
23/09/2020N
AMSUA-A SRFrtcoef_noaa_19_amsua_srf.dat03/11/2021As above
AMSU-Brtcoef_noaa_xx_amsub.dat
26/02/2020hydrotable_noaa_amsub.dat
23/09/2020N
ATMSrtcoef_jpss_0_atms.dat
rtcoef_noaa_20_atms.dat
26/02/2020hydrotable_jpss_atms.dat
hydrotable_noaa_atms.dat (rename/copy jpss file)
23/09/2020N
ATMS SRFrtcoef_jpss_0_atms_srf.dat
rtcoef_noaa_20_atms_srf.dat
03/11/2021As above
COWVRrtcoef_ors_6_cowvr.dat26/02/2020-
CPRrtcoef_cloudsat_1_cpr.dat26/02/2020hydrotable_cloudsat_cpr.dat
23/09/2020Y
DPRrtcoef_gpm_1_dpr.dat26/02/2020hydrotable_gpm_dpr.dat
23/09/2020Y
GEMS1rtcoef_oms_1_gems1.dat24/11/2020-
GEMS1 SRFrtcoef_oms_1_gems1_srf.dat04/11/2021-
GMIrtcoef_gpm_1_gmi.dat26/02/2020hydrotable_gpm_gmi.dat23/09/2020N
GMIrtcoef_gpm_1_gmi_srf.dat05/11/2021As above
HSBrtcoef_eos_2_hsb.dat26/02/2020-
ICI*rtcoef_metopsg_2_ici_o3.dat26/02/2020hydrotable_metopsg_ici.dat23/09/2020N
MADRASrtcoef_meghatr_1_madras.dat26/02/2020hydrotable_meghatr_madras.dat23/09/2020N
MIRASrtcoef_smos_1_miras.dat26/02/2020hydrotable_smos_miras.dat23/09/2020N
MHSrtcoef_noaa_xx_mhs.dat
rtcoef_metop_x_mhs.dat
26/02/2020hydrotable_noaa_mhs.dat
hydrotable_metop_mhs.dat (rename/copy noaa file)
23/09/2020N
MSUrtcoef_noaa_xx_msu.dat26/02/2020-
MTVZA-GYrtcoef_meteor-m_2_mtvzagy.dat26/02/2020hydrotable_meteor-m_mtvzagy.dat23/09/2020N
MWHSrtcoef_fy3_x_mwhs.dat26/02/2020hydrotable_fy3_mwhs.dat23/09/2020N
MWHS2rtcoef_fy3_x_mwhs2.dat26/02/2020hydrotable_fy3_mwhs2.dat23/09/2020N
MWIrtcoef_metopsg_2_mwi.dat26/02/2020hydrotable_metopsg_mwi.dat23/09/2020N
MWRrtcoef_ers_x_mwr.dat
rtcoef_envisat_1_mwr.dat
rtcoef_sentinel3_1_mwr.dat
26/02/2020
23/03/2020
hydrotable_ers_mwr.dat
hydrotable_envisat_mwr.dat (rename/copy ers file)
hydrotable_sentinel3_mwr.dat (rename/copy ers file)
23/09/2020N
FY3 MWRIrtcoef_fy3_x_mwri.dat26/02/2020hydrotable_fy3_mwri.dat23/09/2020N
HY2 MWRIrtcoef_hy2_1_hy2mwri.dat26/02/2020-
MWSrtcoef_metopsg_1_mws.dat26/02/2020hydrotable_metopsg_mws.dat23/09/2020N
MWTSrtcoef_fy3_x_mwts.dat26/02/2020hydrotable_fy3_mwts.dat23/09/2020N
MWTS2rtcoef_fy3_x_mwts2.dat26/02/2020hydrotable_fy3_mwts2.dat23/09/2020N
SAPHIRrtcoef_meghatr_1_saphir.dat26/02/2020hydrotable_meghatr_saphir.dat23/09/2020N
SCAMSrtcoef_nimbus_6_scams.dat26/02/2020-
SMMRrtcoef_nimbus_7_smmr.dat26/02/2020-
SSM/Irtcoef_dmsp_xx_ssmi.dat26/02/2020hydrotable_dmsp_ssmi.dat23/09/2020N
SSMISrtcoef_dmsp_xx_ssmis.dat26/02/2020hydrotable_dmsp_ssmis.dat23/09/2020N
SSM/T2rtcoef_dmsp_xx_ssmt2.dat26/02/2020hydrotable_dmsp_ssmt2.dat23/09/2020N
TEMPEST SRFrtcoef_tempest_0_tempest.dat
rtcoef_tempest_1_tempest.dat
04/11/2021hydrotable_tempest_tempest.dat23/09/2020N
TMIrtcoef_trmm_1_tmi.dat26/02/2020hydrotable_trmm_tmi.dat23/09/2020N
TROPICS**rtcoef_tropics_0_tropics.dat26/02/2020hydrotable_tropics_tropics.dat23/09/2020N
TROPICS** SRFrtcoef_tropics_0_tropics_srf.dat04/11/2021As above
Windsatrtcoef_coriolis_1_windsat.dat26/02/2020hydrotable_coriolis_windsat.dat23/09/2020N

NB “NOAA-5” is TIROS-N.

“SRF” refers to coefficients based on measured spectral responses. These are unique to specific sensors. Other MW coefficients are based on top-hat (box-car) pass bands and are identical for the same sensor on different platforms.

* ICI coefficients are based on current information about channel specifications and are subject to change. Ozone has a significant impact above 200GHz and so the ICI optical depth coefficients support variable O3.

** For simulations of the TROPICS sensor it is highly recommended to use the v13 predictor optical depth coefficient file. RTTOV v13 treats the TROPICS polarisation correctly with respect to surface emissivity and this necessitated a small change in the rtcoef file format which was implemented alongside the new predictors. As such, the polarisation of TROPICS is not treated correctly in RTTOV v12 or in any coefficients based on the v7 predictors.

New hydrotables for RTTOV v13
Hydrotables replace the old Mietables and in RTTOV v13 they allow optical properties to be specified for an arbitrary selection of hydrometeors. The hydrotables linked above contain optical properties for 5 hydrometeors: rain, snow, graupel, cloud liquid water, cloud ice water. In your code, hydrometeor concentrations must be provided in the input cld_profiles(1:nprofiles)%hydro(1:nlevels,1:nhydro) array in this same order, where nhydro=5 for the default tables. You can generate your own hydrotables with a different number of particle types (nhydro).

The optical properties for rain are the same as in the old Mietable files and the cloud liquid water properties are very similar. These are based on results from experiments carried out at ECMWF (Lonitz and Geer, 2018) and use the Rosenkranz (2015) liquid water permittivity parameterisation. The cloud ice water and snow properties have been updated in the new hydrotables and are based on properties from the ARTS database (Eriksson et al 2018). Graupel is new, based on the ARTS column shape. The old totalice hydrometeor has been removed. In summary:

  • rain: Mie sphere, Marshall-Palmer size distribution (unchanged since latest v12 Mietables)
  • snow: ARTS large plate aggregate, Field07 tropical size distribution (updated for v13)
  • graupel: ARTS column, Field07 tropical size distribution (new in v13)
  • cloud liquid: Mie sphere, Gamma size distribution implemented within the new modified gamma framework (mostly unchanged in terms of optical properties, but with small differences from the previous gamma distribution, which was implemented internally using some scientific shortcuts)
  • cloud ice: ARTS large column aggregate, Gamma PSD with generalised modified gamma parameters mu = 0, lambda = 1e4, gamma = 1 and N0 free (updated for v13)

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., 2019: Assessing the impact of different liquid water permittivity models on the fit between model and observations. Atmos. Meas. Tech., 12, 405–429, https://doi.org/10.5194/amt-12-405-2019
  • 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

Cloud optical property files

There are two options for predefined cloud liquid water (CLW) optical properties and two types of option 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 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.

The OPAC dataset uses the liquid water refractive indices from Hale and Querry (1973), but they are specified at reduced spectral resolution which misses some spectral features in the indices. For RTTOV v13 the Segelstein (1981) refractive index dataset was used instead which is a development of the Hale and Querry dataset. The properties based on Segelstein can be identified by a contents “ID” of 1 in the CLW sections of the sccldcoef file as opposed to 0 for the properties based on OPAC/Hale and Querry.

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

  • Hale, G. M. and M. R. Querry, 1973: Optical constants of water in the 200nm to 200μm wavelength region, Appl. Opt. 12, 555- 563.
  • Segelstein, D., 1981: The Complex Refractive Index of Water. Masters Thesis, Dept Physics, U. Missouri-Kansas City.

Deff CLW scheme
These optical properties 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). RTTOV provides a parameterisation for cloud liquid water effective diameter. Alternatively you can specify the cloud effective diameters explicitly in the profiles(:)%clwde(1:nlayers) array. See the user guide for more details.

Previously the OPAC (Hale and Querry) refractive indices were used for these properties. For RTTOV v13 they have also been updated using the Segelstein dataset, which is also used for the libRadtran Mie properties. The properties based on Segelstein can be identified by a contents “ID” of 1 in the CLW sections of the sccldcoef file as opposed to 0 for the properties based on OPAC/Hale and Querry.

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

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(:)%icede_param 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 schemes
These optical properties are parameterised in terms of ice water content and temperature. Multiple parameterisations are available (see the RTTOV user guide). 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 icede_param and icede profile variables are ignored.

The data for these parameterisations are stored in the code rather than in external files. MFASIS is not currently compatible with the Baran ice schemes.


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., Benedetti, A., Flemming, J., Kipling, Z., Remy, S., 2020: An aerosol climatology for global models based on the tropospheric aerosol scheme in the Integrated Forecasting System of ECMWF, Geosci. Model Dev., 13(3), 1007–1034 doi:10.5194/gmd-13-1007-2020

Reference profiles and regression limits

RTTOV rtcoef coefficients

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 v13 predictors introduced in RTTOV v13 support different selections of optional variable trace gases as indicated in the filename and listed below. Note that simulations using a coefficient file with more optional variable gases run slower. RTTOV v13 supports all RTTOV v12-compatible optical depth coefficients based on the v7, v8 and v9 predictors. The main difference with the v13 predictors is that solar radiation is supported in all coefficient files and as such all files support all channels (visible-IR) for which we have spectral response data.

  • v13 predictors rtcoef_*_o3 : O3 (similar to v7 predictors, but now with solar radiation)
  • v13 predictors rtcoef_*_o3co2 : O3 and CO2 (similar to v8 predictors, but now with solar radiation; similar to v9 predictors with variable O3 and CO2)
  • v13 predictors rtcoef_*_7gas : O3, CO2, N2O, CO, CH4 and SO2 (similar to v9 predictors with all trace gases)

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 RTTOV v12 and v13 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 earlier coefficient files contain the stretched limits: despite this difference the behaviour of RTTOV v12/v13 is the same as v11 and earlier in respect of the profile limits.

PC-RTTOV

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.