Missing gas transmittance file for S2B MSI

[matheushtavares]

Hello all,

I'm trying to run l2gen (9.11.0-V2025.1) over a Sentinel-2B image, but using even the basic command line requests a gas transmittance file as input. I tried:
l2gen ifile=/home/matheus/Documents/GET/py_data/S2L1C/S2B_MSIL1C_20240606T143749_N0510_R096_T20LLQ_20240606T161957.SAFE/manifest.safe ofile=/home/matheus/Documents/GET/SeaDAS/20240606/SeaDAS_20240606.nc

and get this error:
-E- clo_getOptionString: option=gas_transmittance_file needs to be set

In previous versions of l2gen, this option was not mandatory. So I'm wondering where can I get this file? Donwloading the ancillary data using getanc donwloads meteorological data, but I don't think this is the correct input.
Thanks for the help!

Matheus Tavares

[OB SeaDAS - dshea]

Sorry about that. We do not have a gas transmittance table for MSI yet.
Just put this on the l2gen command line or par file.

gas_transmittance_file=none

don

[matheushtavares]

Thank you for your response.
Adding this piece of code, I could run l2gen but it didn't produce results (Flag #31: PRODFAIL 30140100 100.0000), possibly because of the configurations I need for my study area (Madeira river in the Amazon). Therefore I tried this code:

l2gen ifile=/home/matheus/Documents/GET/py_data/S2L1C/S2B_MSIL1C_20240606T143749_N0510_R096_T20LLQ_20240606T161957.SAFE/manifest.safe ofile=/home/matheus/Documents/GET/SeaDAS/20240606/SeaDAS_20240606.nc oformat=netcdf4 atmocor=on mode=0 aer_opt=-3 aer_wave_short=864 aer_wave_long=1611 glint_opt=1 brdf_opt=0 gas_opt=32 met1=/home/matheus/Downloads/SeaDAS/ocssw/var/anc/2024/158/GMAO_MERRA2.20240606T140000.MET.nc met2=/home/matheus/Downloads/SeaDAS/ocssw/var/anc/2024/158/GMAO_MERRA2.20240606T150000.MET.nc met3=/home/matheus/Downloads/SeaDAS/ocssw/var/anc/2024/158/GMAO_MERRA2.20240606T150000.MET.nc ozone1=/home/matheus/Downloads/SeaDAS/ocssw/var/anc/2024/158/GMAO_MERRA2.20240606T140000.MET.nc ozone2=/home/matheus/Downloads/SeaDAS/ocssw/var/anc/2024/158/GMAO_MERRA2.20240606T150000.MET.nc ozone3=/home/matheus/Downloads/SeaDAS/ocssw/var/anc/2024/158/GMAO_MERRA2.20240606T150000.MET.nc gas_transmittance_file=none

for which I get the following error:
-E- /home/dshea/ocssw/src/l2gen/gas_trans.c: Failed to open none

Does it mean that for the configurations I used l2gen can't run without the gas transmittance file?
Thank you again.

Matheus

[OB ScienceSW - jlindo1]

Hi Matheus,

This issue should be resolved in an upcoming tag, T2025.8. Once released, you will be able to install this tag using the command install_ocssw --tag `cat $OCSSWROOT/.manifest_tag` --all.

I hope this helps!

Best,
Jakob

[OB SeaDAS - dshea]

we have not generated gas transmittance tables for MSI. Your command will work if you get rid of "gas_opt=32".

don