Questions about the Transient Land Unit Change

[Danbi]

Dear Team,

I am currently working on running CESM2.1.3 (cesm2.1.3-rc.01-0-g0596a97 with clm5.0.30) using landuse_timeseries, and I would like to compare this experiment with a control experiment where landuse_timeseries is not applied. Below are the details of the experiments;

1. Control Experiment
(1) Case Setup: ./create_newcase --case /scratch/g157a05/CESM2.1.3/cases/control_exp --compset 2000_CAM60_CLM50%BGC-CROP-CMIP6DECK_CICE%CMIP6_POP2%ECO%ABIO-DIC_MOSART_CISM2%NOEVOLVE_WW3_BGC%BPRP --res f09_g17 --machine nurion --pes ./n21x3.xml --run-unsupported
(2) Simulation period: 2000.01 to 2004.12 with restart files

2. LUC Experiment
The setup is the same as the control experiment, with the following additional configurations in user_nl_clm:
&clm_inparm
fsurdat = '/scratch/g157a02/CESM2.1.3/inputdata/lnd/clm2/surfdata_map/release-clm5.0.18/surfdata_0.9x1.25_hist_78pfts_CMIP6_simyr1850_c190214.nc'
use_init_interp = .true.
(control run used 'simyr2000' file)

&dynamic_subgrid
flanduse_timeseries = '/scratch/g157a02/CESM2.1.3/inputdata/lnd/clm2/surfdata_map/release-clm5.0.18/landuse.timeseries_0.9x1.25_SSP1-2.6_78pfts_CMIP6_simyr1850-2100_c190214.nc'


The LUC experiment runs successfully. However, upon analyzing the output (e.g., PCT_LANDUNIT and TLAI) from the LUC experiment,
it appears that PCT_LANDUNIT are not reflected in TLAI (see the figure below for an example grid).

I also added to the lnd_in files from each experiment.
Could you please provide suggestions regarding this issue?
Thank you for your time.

Best regards,
Danbi

 

[oleson]

I'm not sure what you mean by "PCT_LANDUNIT" are not reflected in TLAI. LAI is prognostic in the simulations you are running, so there can be changes in LAI independent of changes in landunits. TLAI also will include LAI from the crop model, so it also depends on what PCT_CROP is doing in the transient simulation.