RTTOV v13 Code Updates and Known Issues

RTTOV v13 Code Updates

Updates and bug fixes to RTTOV v13 are published here. There are separate pages for RTTOV v12 bug fixes and RTTOV v11 bug fixes.

Known bugs and issues

Please report any bugs you find in RTTOV using the NWP SAF Helpdesk. The official release packages for each version don’t contain the bug fixes or updates listed here under that version so you should apply any fixes provided below. Bugs/updates in earlier versions have been fixed/implemented in later versions.

DateType/StatusDescription
31/08/2021Bug - fixedAffects: VIS/IR cloud simulations using the Ou and Liou ice effective diameter parameterisation (icede_param = 1) with the Baum ice properties (v13.0 only).

Issue: the Ou and Liou parameterisation is valid for temperatures in the range -60 to -20 deg C. The lower bound is incorrectly applied meaning that for temperatures below ~205 K the calculated effective diameters are set to a minimum of 10 microns instead of 22 microns. To give an estimate of the impact, the fixed code has been compared to the original for the eight SEVIRI IR channels over the 137L NWP SAF profile dataset (25000 profiles). The bias across all channels and profiles is ~0.2 K, standard deviation ~0.8 K, and maximum difference ~26 K.

Fix: download and extract this tarball in the src/main/ directory, and recompile RTTOV (a clean compilation is not necessary).
31/08/2021Bug - fixedAffects: MFASIS TL/AD/K models for profiles with mixed phase cloud (v13.0 only).

Issue: a TL/AD/K coding error yields incorrect results for some profiles with layers containing both liquid and ice cloud.

Fix: download and extract this tarball in the src/main/ directory, and recompile RTTOV (a clean compilation is not necessary).
14/06/2021Bug - fixedAffects: FASTEM 3-6 10m wind u and v component TL/AD/K (all versions of RTTOV from v13.0 back to v9 at least).

Issue: there is a TL/AD/K bug in the FASTEM code related to the wind azimuth direction calculation. This affects all versions of FASTEM that account for azimuthal variation (FASTEM-3 and later). Wind u/v adjoints and Jacobians are incorrect when the input wind u and v have opposite signs. The direct model is not affected.

Fix: download and extract this tarball in the src/main/ directory, and recompile RTTOV (a clean compilation is not necessary). This fix is for RTTOV v13.0 only. See the RTTOV v12 bug fix table for v12 fixes.

This bug fix affects reference data for the test_rttov13.sh and test_multi_instrument.sh test scripts: updated test reference data are available and should be extracted in the rttov_test/ directory. These reference data are only for RTTOV v13.0.
11/06/2021Bug - fixedAffects: NLTE bias correction (RTTOV v13.0, v12.x).

Issue: the temperature predictors calculated for the NLTE bias correction did not average temperature values over the correct set of levels leading to errors in the computed bias correction. An indication of the impact of the bug is given in this plot which shows IASI BT differences for the fixed code minus the original code for the NLTE-affected band for an 83 diverse profile set simulated for satellite zenith angles between 0-60 degrees and solar zenith angles 0-80 degrees, each in steps of 10 degrees, with all combinations of angles tested.

Fix: download and extract this tarball in the src/main/ directory, and recompile RTTOV (a clean compilation is not necessary). This fix can be applied to RTTOV v13.0, v12.3, v12.2 and v12.1.
20/05/2021Bug - fixedAffects: PC-RTTOV simulations with aerosols when the interpolator is not used. (RTTOV v13.0, v12.3, v12.2).

Issue: two array indices were the wrong way around which causes run-time failures.

Fix: download this source file to the src/main/ directory, and recompile RTTOV (a clean compilation is not necessary). This fix can be applied to RTTOV v13.0, v12.3 and v12.2.
13/04/2021Bug - fixedAffects: RTTOV-SCATT hydrotable generation when reading the ARTS database. The problem was reported for Ubuntu 20.04 LTS and gcc/gfortran 9.3.0, but the bug does not affect other compilers/platforms tested by the RTTOV development team. The bug does not affect the hydrotables available for download on the coefficients download web page, nor does it affect any RTTOV-SCATT simulations. (RTTOV v13.0 only).

Issue: the code which ingests ARTS database reads more elements than are in the file which is assumed to trigger a linefeed, but does not do so for certain compilers/platforms (see above) in which case the output hydrotable may contain erroneous optical properties.

Fix: download this source file to the src/mw_scatt_coef/ directory and recompile RTTOV (a clean compilation is not necessary).
01/02/2021Bug - fixedAffects: rttov_coef_download.sh script for downloading RTTOV v13 coefficient files.

Issue: if you choose the option not to continue previously interrupted downloads the script does not work properly. It works fine if you select "y" to this question.

Fix: here is a fixed version of the script.
17/12/2020Bug - fixedAffects: RTTOV-SCATT hydrotable generation code when different permittivity models are specified for different hydrometeors. This is an unlikely usage scenario and the bug does not affect the hydrotables available for download on the coefficients download web page, nor does it affect any RTTOV-SCATT simulations. (RTTOV v13.0 only).

Issue: incorrect array indexes mean that the water/ice permittivity models for the previous hydrometeor are used for the current hydrometeor instead of those specified by the user.

Fix: download this source file to the src/mw_scatt_coef/ directory and recompile RTTOV (a clean compilation is not necessary).