Regarding the issue of Track File in HISTORY.rc

[helpyuan]

Your name

liumy

Your affiliation

CAMS

Please provide a clear and concise description of your question or discussion topic.

Hi all,

I have been using track_file to sample the model results recently (https://gchp.readthedocs.io/en/dev/supplement/satellite-overpass.html#output-along-a-track).

# Question 1:
GCHP has output the corresponding file, but there seems to be a slight issue with the latitude and longitude inside, as shown in the figure:

The above result is to set rcycle_track to True (SpeciesSample.recycle_track: .true.). But when I set recycle_track to .false. (SpeciesSample.recycle_track: .false.), meaning I don't want to reuse a track_file (if I understand correctly), it seems that no sampling was done, and the output result is shown in the figure (the time dimension is zero):

So is this a bug? Or is there a problem with my track file? Here are my files:
HISTORY.rc.txt
trackfile_test_only_latlontime_20190701.txt

# Question 2:
Following the above, when I set track_file to 'trackfile_test_only_latlontime_%y4%m2%d2.nc' and recycle_track to .false. , GCHP doesn't seem to be recognized. So I would like to ask if it is possible to read different track_file based on the date during a simulation process?

It seems that it is not possible to upload netCDF files here. If you need my track_file, I can provide it to you through email or other ways.

version

GCHP-14.4.1

[lizziel]

Hi @helpyuan, the satellite overpass feature of GCHP may very well have a bug. We do not test it and are not aware of anyone using it. We will take a look at it as we have time.

[helpyuan]

Thanks @lizziel, looking forward to your good news.

[yuanjianz]

@yantosca, just a random related question here. Does SatDiagn work for GCHP or just GC-Classic only? I read the lines here: geoschem/geos-chem#770 (comment). It seems get_local_time function is not yet available in GCHP.

Together with this issue, does it mean currently we do not have satellite overpassing capability within GCHP or models other than GC-Classic?

[yantosca]

@yuanjianz: The SatDiagn and SatDiagnEdge only work for GC-Classic. All of the diagnostic capability of GCHP is handled by the MAPL History component.

I know there was interest in having the similar output in MAPL but I'm not sure where that stands. @lizziel is our MAPL guru.

[lizziel]

@yuanjianz, the satellite overpass capability of GCHP is restricted to the output along a track. If there is a currently a bug there then we will need to fix it. This is not currently a priority for version 14.5 so it is currently not being worked on.