Hello, I noticed that the CLM5 model has integrated parameters for ozone damage to vegetation. Currently, I am using the offline CLM with IHistClm50BgcCrop, and I have set use_ozone = .true. However, I seem to be unable to locate the surface ozone concentration data used in this process. Could you kindly clarify where the model acquires this data? I am curious whether it utilizes annual or monthly averages and if the data is read from external files. Additionally, I am interested in replacing the current ozone concentration data with my own. Could you please advise on how to do this? I would appreciate it if you could provide any information related to this issue.
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Ozone Damage in Offline CLM: Source and Replacement of Surface Ozone Concentration Data
- Thread starter zhangqr
- Start date
Hi, the surface ozone concentration in offline mode is read in through the CDEPS code. You can see where it is located via the datm.streams.xml file in the run directory- i.e. on derecho it would be in /glade/scratch/${user}/${case_name}/run by default.
In an example case I have it has:
This data is monthly, and it is downscaled to daily averages. There is currently a PR in to downscale the data further to sub-daily diurnal cycles, but this is not available on the main branch of CTSM yet.
To replace the current ozone concentration data with your own, you would want to use the user_nl_datm_streams file (in your case directory) with your file name(s) and other relevant updates.
In an example case I have it has:
<stream_info name="preso3.hist">
<taxmode>cycle</taxmode>
<tintalgo>linear</tintalgo>
<readmode>single</readmode>
<mapalgo>bilinear</mapalgo>
<dtlimit>1.5</dtlimit>
<year_first>1850</year_first>
<year_last>2014</year_last>
<year_align>1850</year_align>
<vectors>null</vectors>
<meshfile>/glade/campaign/cesm/cesmdata/inputdata/share/meshes/fv0.9x1.25_141008_polemod_ESMFmesh.nc</meshfile>
<lev_dimname>null</lev_dimname>
<datafiles>
<file>/glade/campaign/cesm/cesmdata/inputdata/cdeps/datm/ozone/O3_surface.f09_g17.CMIP6-historical-WACCM.001.monthly.185001-201412.nc</file>
</datafiles>
<datavars>
<var>O3 Sa_o3</var>
</datavars>
<offset>0</offset>
</stream_info>
This data is monthly, and it is downscaled to daily averages. There is currently a PR in to downscale the data further to sub-daily diurnal cycles, but this is not available on the main branch of CTSM yet.
To replace the current ozone concentration data with your own, you would want to use the user_nl_datm_streams file (in your case directory) with your file name(s) and other relevant updates.
Hi,Hi, the surface ozone concentration in offline mode is read in through the CDEPS code. You can see where it is located via the datm.streams.xml file in the run directory- i.e. on derecho it would be in /glade/scratch/${user}/${case_name}/run by default.
In an example case I have it has:
This data is monthly, and it is downscaled to daily averages. There is currently a PR in to downscale the data further to sub-daily diurnal cycles, but this is not available on the main branch of CTSM yet.
To replace the current ozone concentration data with your own, you would want to use the user_nl_datm_streams file (in your case directory) with your file name(s) and other relevant updates.
Thank you for your kind and detailed response. It has been very helpful!
The version I am currently using is CTSM release-clm5.0.35, and it seems that there is no datm.streams.xml file mentioned by you in the model I am using. Instead, it still uses datm.streams.txt.* to specify data sources. I suspect this might be a version issue, as I have noticed the datm.streams.xml file in some newer versions of the CTSM code. I would like to know if I am interested in using the monthly ozone data you mentioned to simulate ozone damage to vegetation, which version of CTSM would be suitable for this purpose currently? Any recommendations would be greatly appreciated.
Thank you!
Ah okay, so you are still using mct rather than nuopc, and actually you are probably *not* using the ozone data files, but rather a constant value.
Is there a reason you are using a release version rather than the master branch on the CTSM repository? You could probably just use the master branch.
Is there a reason you are using a release version rather than the master branch on the CTSM repository? You could probably just use the master branch.
Yes, the version I currently have uses a fixed value of ozone concentration. I installed the model some time ago and I wasn’t aware that the master branch had been updated. Thank you for bringing that to my attention! I'll switch to the master branch.Ah okay, so you are still using mct rather than nuopc, and actually you are probably *not* using the ozone data files, but rather a constant value.
Is there a reason you are using a release version rather than the master branch on the CTSM repository? You could probably just use the master branch.
Thanks！：）Great, let me know if you run into any issues.