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Guidance on Running with LME datasets with CESM2.1.3 (CLM5)

oleson

Keith Oleson
CSEG and Liaisons
Staff member
Unfortunately, we can't provide any specific answers since we don't have any experience with this type of workflow. Our suggestion is to experiment with a short sequence of simulations, e.g., just a few years for each segment, to see how the workflow should be implemented.
 

wvsi3w

wvsi3w
Member
Unfortunately, we can't provide any specific answers since we don't have any experience with this type of workflow. Our suggestion is to experiment with a short sequence of simulations, e.g., just a few years for each segment, to see how the workflow should be implemented.
Thank you Keith for your suggestion.

From 500 to 1850, it is better to use the I1850 compset, and then from 1850 onwards, using a transient compset like IHIST1850 is suggested.

So, because there is a need to change the compset from one point in time, it is better if I divide the simulation into two parts (at least):
from year 500 to 1850 (with I1850 compset that I use atm forcings from 500 to 1850). Then using IHIST1850 compset from 1850 onwards (setting the atm forcing accordingly).

But do you have a rough idea about the stream files? I mean is there another way of writing thousands of lines for the file names? I can definitely write it into the stream file but I was thinking maybe you know another way.
Because lets say I am doing the two parts simulation, then from 500 to 1850 my stream files will be like:

<filePath>
/home/USER/projects/def-xxx/USER/inputdata/atm/datm7/atm_forcing.datm7.GSWP3.0.5d.v1.c170516/Precip
</filePath>
<fileNames>
0500-01.nc
0500-02.nc
0500-03.nc
0500-04.nc
.
.
.
.
.
1850-11.nc
1850-12.nc


which is 16,200 lines of file names!
It is fine if this is the norm, but I thought maybe you guys know some other way for writing the names into the stream when it is a lot of files.
 

oleson

Keith Oleson
CSEG and Liaisons
Staff member
I think you could change the paths to your data by modifying:

cime/src/components/data_comps/datm/cime_config/namelist_definition_datm.xml

I think the list of file names would then be setup automatically by setting DATM_CLMNCEP_YR_START, DATM_CLMNCEP_YR_END.

The names would be different from yours, e.g., clmforc.GSWP3.c2011.0.5x0.5.Prec.1901-01.nc versus 1901-01.nc, but you could either change your names to match or link your files to those filenames.
 

wvsi3w

wvsi3w
Member
I think you could change the paths to your data by modifying:

cime/src/components/data_comps/datm/cime_config/namelist_definition_datm.xml

I think the list of file names would then be setup automatically by setting DATM_CLMNCEP_YR_START, DATM_CLMNCEP_YR_END.

The names would be different from yours, e.g., clmforc.GSWP3.c2011.0.5x0.5.Prec.1901-01.nc versus 1901-01.nc, but you could either change your names to match or link your files to those filenames.

Dear Keith, @oleson
Sorry, I have a question regarding the datm_in file.
In this thread related to the "1" in the user_datm*, you suggested changing that "1" to 1901, and the align issue got fixed. That person's problem is not my problem, but I found this thread because I want to specify something:

In my spin-up, which worked fine, this was my datm_in for IHIST compset (which I modified the years):

streams = "datm.streams.txt.CLMGSWP3v1.Solar 500 500 500",
"datm.streams.txt.CLMGSWP3v1.Precip 500 500 500",
"datm.streams.txt.CLMGSWP3v1.TPQW 500 500 500",
"datm.streams.txt.presaero.trans_1850-2000 1850 1850 1850",
"datm.streams.txt.topo.observed 1 1 1",
"datm.streams.txt.co2tseries.20tr 1850 1850 1850"
taxmode = "cycle", "cycle", "cycle", "cycle", "cycle", "cycle"

And this was for I1850 compset:

streams = "datm.streams.txt.CLMGSWP3v1.Solar 1 500 500",
"datm.streams.txt.CLMGSWP3v1.Precip 1 500 500",
"datm.streams.txt.CLMGSWP3v1.TPQW 1 500 500",
"datm.streams.txt.presaero.clim_1850 1 1850 1850",
"datm.streams.txt.topo.observed 1 1 1"
taxmode = "cycle", "cycle", "cycle", "cycle", "cycle"

I am assuming those 1s are the align in I1850 compset (?)

As this compset is better for having constant variables (such as urban, co2, etc) so I used I1850 in my last spin-up and it worked fine, all reached equilibrium.

I was setting up my transient run, and the start date is 500 and end is 1849, so what should I do with align here, do I leave it to be 1? Is the format below correct for the transient run?

streams = "datm.streams.txt.CLMGSWP3v1.Solar 1 500 1849",
"datm.streams.txt.CLMGSWP3v1.Precip 1 500 1849",
"datm.streams.txt.CLMGSWP3v1.TPQW 1 500 1849",
"datm.streams.txt.presaero.clim_1850 1 1850 1850",
"datm.streams.txt.topo.observed 1 1 1"
taxmode = "cycle", "cycle", "cycle", "cycle", "cycle"

Or should I change that 1 when we are in transient run from year 500 to 1849? However, since the first part of my transient run is from 500 to 1849 so I will have the constant values for CO2, aerosol, urban, fire, ... and only my forcings (Precip, Solar, TPHWL) are transient (from 500 to 1849).

Also, I think the taxmode part should be different? How about other parts of my datm_in (e.g. tintalgo, mapalgo, readmode, ...)?

P.S. will that align being "1" in the spin-up, affect the results of spin-up? should I redo it with "500 500 500"?
 

wvsi3w

wvsi3w
Member
Because I remember when we used IHIST compset the datm_in for the CO2 part and taxmode shows this:

"datm.streams.txt.co2tseries.20tr 1850 1850 2014"
taxmode = "cycle", "cycle", "cycle", "cycle", "cycle", "extend"

which means the co2 stream is "extend", and I thought since IHIST was a transient compset from 1850 onwards, then for all transients we should change the taxmode (and other things like tintalgo, ...?). But since my first part of transient is from 500-1849, then technically I wont have much transient except for the prescribed 7 variables (Precip, Solar, TPHWL).

you see what I mean?!
 

wvsi3w

wvsi3w
Member
Because I remember when we used IHIST compset the datm_in for the CO2 part and taxmode shows this:

"datm.streams.txt.co2tseries.20tr 1850 1850 2014"
taxmode = "cycle", "cycle", "cycle", "cycle", "cycle", "extend"

which means the co2 stream is "extend", and I thought since IHIST was a transient compset from 1850 onwards, then for all transients we should change the taxmode (and other things like tintalgo, ...?). But since my first part of transient is from 500-1849, then technically I wont have much transient except for the prescribed 7 variables (Precip, Solar, TPHWL).

you see what I mean?!
I believe the align part being 1, is the most important question here, and what does it mean when align is 1.

Because if I dont know what that "1" does, then I can not trust my spin-up results. Also, that would impact my understanding of the current transient run.

Thank you in advance for your support
 
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