default initial condition for CLM5.0-BGC-CROP

[xgao304]

Dear Sir:

For the CLM5-BGC-crop compset (i.e., 2000_DATM%GSWP3v1_CLM50%BGC-CROP_SICE_SOCN_SROF_SGLC_SWAV), the default initial condition would be automatically set as follows:

clmi.I2000Clm50BgcCrop.2011-01-01.1.9x2.5_gx1v7_gl4_simyr2000_c190312.nc

I would like to know how this initial condition is generated. Is it based on a coupled run or an offline run? If it is offline, what forcing was used? What is the other relevant model setup to generate this initial condition? Such information would help gauge under what scenarios this initial condition could be reasonably used. Thanks.

 

[slevis]

Hello @xgao304,

I am also not familiar with the history of this file so I used "ncdump" to see the global attributes of the file. These seem relevant:

case_id = "SMS_Ld1.f19_g17_gl4.I2000Clm50BgcCrop.cheyenne_intel.clm-default.20190311_010757_vvomx0"
Notes_190311 = "Interpolated from clmi.I2000Clm50BgcCrop.2011-01-01.1.9x2.5_gx1v7_gl4_simyr2000_c180715.nc. This is the finidat_interp_dest.nc file from SMS_Ln1.f19_g17_gl4.I2000Clm50BgcCrop.cheyenne_intel, run from release-clm5.0.20"

...and then I did "ncdump" on the file mentioned in Notes_190311:

case_id = "SMS_Ln1.f19_g17_gl4.I2000Clm50BgcCrop.cheyenne_intel.clm-default.C.ctsm10dev004chlist"

Unfortunately this is not enough information to answer your questions. My best guess is that this file was generated from a long offline run, but I don't know the forcing data or length of simulation. @erik or @oleson do you know how to find this info?

Otherwise though, it is often best to complete your own model spin-up if you need to know how the model was spun up for your research.

Sam Levis

 

[slevis]

I found more information about the spun up files here:

1.1.1. Introduction — ctsm release-clm5.0 documentation

This may still not answer all your questions, but it is worth reading.

 

[xgao304]

Sam, thanks so much for the information.

The main purpose to choose the default initial conditions instead of completing my own model spin-up is to save some time.
I also found some information for clm5-bgc-crop spin-up from the ctsm online doc (1.5.5. Spinup of CLM5.0-BGC-Crop — ctsm release-clm5.0 documentation). However, it does not specifically answer my question.
It simply discusses how the spin-up is performed and how to determine if the equilibrium is reached.