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

wvsi3w

wvsi3w

wvsi3w
Member
oleson said:
Yes, it is.
Click to expand...
Thank you very much dear Keith for your answer.
I tested the case with these changes into my user_nl_clm and thankfully it did work (there is no need to assign the surfdata file as it is already set):
Code: 
soil_layerstruct= '23SL_3.5m'
use_init_interp = .true.

check_dynpft_consistency =.false.
do_transient_crops=.false.
do_transient_pfts=.false.
flanduse_timeseries=' '

So, until here I have set land cover change to be constant (1850), landuse_timeseries are also omitted.
before I ask my question I need to refer to this quote from you regarding the dtlimit and monthly dataset. I have talked with my supervisors and couple of other colleagues and we decided to stick with the monthly data as land has a longer memory than atmosphere and monthly can be accepted for the goal of our project. However, I have a mini question about that dtlimit which I couldn't figure out why 3hourly is equal to 1.5 and monthly is 1.e36? what is 1.5 and what is 1.e36? is this 1x e to the power of 36? is it seconds in a month (doubt it), hours???

Back to my main question, now that almost everything is set for a spin-down simulation using data from year 500, I need to know if there is a way to set CO2 for that year in the model because the plot below is from the reference where my dataset has used its GHGs and I want to have similar CO2 as well. It is showing almost constant value of CO2 from year 500 to 1850 (I guess it is 275 ppm). The CLM5 documentation shows ways of running with historical CO2, but this period that I am trying to run (and trying to spin-down) I believe is pre-historical.


1747930690833.png
From (Meinhausen et al., 2017): doi:10.5194/gmd-10-2057-2017

Therefore, I think we need to have either a constant value for CO2 (like 275ppm) but I don't know how to set it in my case (is it supposed to be set in user_nl_clm as well? and how?), or we can have a transient CO2 file because I see this file "fco2_datm_global_simyr_1750-2014_CMIP6_c180929.nc" exist in the CO2 folder of my input data and I think we should either change it or set some option in the namelists to ignore this file?

Another concern is that there are other inputdata for land "urbandata", "firedata", ... that are for the historical period and not pre-historical. Should we set them off somehow as well or we can ignore these files for my case? how about the solar file inside "/inputdata/atm/cam/solar/" (SolarForcing1995-2005avg_c160929.nc)? Can we ignore this one as well or should we turn this one off as well?

Thank you in advance for your support.
 
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