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

[slevis]

The path of the file
inputdata/atm/cam/solar/SolarForcing1995-2005avg_c160929.nc
and the values that you quoted
1361.1
suggest to me that this file contains the top-of-atmosphere solar radiation used by an active atmosphere model (CAM). If you do not use an active atmosphere model, then I suspect that this file and its values are ignored.

I do not have answers about volcanic forcing. I hope somebody else will answer.

 

[wvsi3w]

The path of the file
inputdata/atm/cam/solar/SolarForcing1995-2005avg_c160929.nc
and the values that you quoted
1361.1
suggest to me that this file contains the top-of-atmosphere solar radiation used by an active atmosphere model (CAM). If you do not use an active atmosphere model, then I suspect that this file and its values are ignored.

I do not have answers about volcanic forcing. I hope somebody else will answer.

Dear Sam, Thank you so much for your answer.

I understand. So in a fully coupled simulation or a CLM-CAM simulation, I could use my tsi instead of the default one (?)

 

[slevis]

I understand. So in a fully coupled simulation or a CLM-CAM simulation, I could use my tsi instead of the default one (?)

I have never tried this myself, but I do not see why not.

 

[wvsi3w]

I have never tried this myself, but I do not see why not.

And do you know if we can assign its path to a different directory in our case, like we do for other forcings?
I looked at the CaseDocs and user_namelists, but I dont see where we can do that.

Because if I need to just remove that file from inputdata/atm/cam/solar/ and replace it with my file then I should wait until first member is finished then replace it with another member solar file which is not rational.

 

[wvsi3w]

And do you know if we can assign its path to a different directory in our case, like we do for other forcings?
I looked at the CaseDocs and user_namelists, but I dont see where we can do that.

Because if I need to just remove that file from inputdata/atm/cam/solar/ and replace it with my file then I should wait until first member is finished then replace it with another member solar file which is not rational.

And another question would be why we have this path inputdata/atm/cam/solar/ in IHIST compsets, but we dont have it in I1850 compsets? The first one is historical, the second one is used when we want constant values of urban, landuse, etc.

I personally cant see the reason why we dont have that path in I1850 compset inputdata. In I1850, we only see cam/chem path and nothing else.

 

[slevis]

And do you know if we can assign its path to a different directory in our case, like we do for other forcings?
I looked at the CaseDocs and user_namelists, but I dont see where we can do that.

Because if I need to just remove that file from inputdata/atm/cam/solar/ and replace it with my file then I should wait until first member is finished then replace it with another member solar file which is not rational.

I have not tried this myself but here are my thoughts:

I suspect that the solar file of your choice could end up in atm_in via user_nl_cam or maybe it would be specified in a "streams" file. Overwriting the default file with your file seems the easiest immediate solution, though it could confuse you in the future, because you could forget which data you actually used for your various simulations. In any case, you could keep trying these ideas until something works.

You could also post in the CAM Forum where people are more likely to know about this file.

About your last question, I am surprised in the opposite sense than you are:
I would expect no such file in I1850, I2000, IHist or any I-compset because, from my understanding, this is top-of-atmosphere radiation that matters only if you have an active atmosphere model in your compset. If such a file is specified in I-cases, then I would expect no effect from changing it because I would not expect top-of-atmosphere data to be used in an I-case.

Again, you may get more conclusive responses in the CAM forum about this file.

 

[wvsi3w]

Hello again,
I would like to ask another question related to my experiment. I would be glad to know your thoughts on it dear @slevis and dear @oleson

First, to remind us of my simulation conditions:
Starts at year 500CE, ends in 2000. Has 43m bottom boundary in the shallow version (using the 23SL_3.5m soil layer structure) and 500m in deep version (modified 23SL_3.5m), uses two members of monthly 1500 years of forcings (started from an initial condition (Spun-Down) that picked first 30years of forcings from each member to better capture the climatology of that time (500-529CE)), my members of 1500y forcings have the variables required for land-only simulations (TPHWL, Prec, Solar) and are monthly temporal resolution, 1deg spatial. I have used (I1850Clm50BgcCrop --res f09_g17) for my 500 to 1850 period (that has constant CO2 and aerosol of 1849, and has no landuse change), and I have used (IHistClm50BgcCrop --res f09_g17) for my 1850-2000 period that has transient CO2, etc for that period.

So, the simulations are done and I have compared my results with the observation, and I see that there are some differences between my deep model and the shallow (default) model in regards to the end year of the simulation (year 2000) for permafrost extent, but it is not very significant. Therefore, based on several studies that extended their simulation onwards to the future, I was wondering how I could do the same thing here?

What compset should I use from 2000 to 2100? I mentioned that I used IHistClm50BgcCrop for 1850-2000 (with my own forcing scenarios), but with SSP scenarios, how should I do it, especially because my forcings were monthly, and I think the future scenarios available as compset in CLM5 are 6-hourly or finer resolution?

I see that in the compset list, there are 8 types of SSP compset there, but I am not sure if I could just pick one (ISSP245Clm50BgcCrop). Does it start from 2000, or would I miss 20 years, as they probably start from 2020?

I would like to start this future scenario from my own restart file of my already finished simulation that ended in 2000 (from 1500 years of simulating monthly), so that I could see what would happen to my experiment in the future using different future scenarios if we start them with my own initial conditions.

P.S. Also, any Idea if there are developed future scenarios available for 2100 onwards (lets say till 2300?)