Seeking guidance Satellite Phenology Spin up: Spin-up duration and use of MODIS LAI and SAI data

[Chiru]

I'm attempting to use Satellite Phenology to run a CLM5 (CESM2.2.0) simulation. I have few doubts about the Satellite Phenology's spin-up.
According to what is said in the website https://www2.cesm.ucar.edu/models/cesm1.2/clm/models/lnd/clm/doc/UsersGuide/x12536.html
https://www2.cesm.ucar.edu/models/cesm1.2/clm/models/lnd/clm/doc/UsersGuide/x12591.html

Can I use the compset of 1850_DATM%GSWP3v1_CLM50%SP_SICE_SOCN_MOSART_SGLC_SWAV and use the domain and surface (1850) for my regional study?
and perform the spin-up for 50 years using my own atmospheric forcing data from 1991 to 2015 (0.1 degree resolution) (RESUBMIT=2).
Following that, restart file obtained from this start-up simulation shall I use for my further simulations.
Or, as described in 1.5.4. Spinning up the Satellite Phenology Model — ctsm CTSM master documentation,
can I start my simulations from a default initial file that is setup as part of the selected compset (for my regional study for the duration of 1980-2020)
2000_DATM%GSWP3v1_CLM50%SP_SICE_SOCN_MOSART_SGLC_SWAV or 1850_DATM%GSWP3v1_CLM50%SP_SICE_SOCN_MOSART_SGLC_SWAV

2) In the following post How to configure a transient climate simulation with constant surface data?
it was mentioned that in Satellite Phenology the CLM5 model will use the MODIS LAI and SAI which is available for only for 2003-2015 so even though in my simulations
if I am using the Forcing data for the duration of 1980-2020 the model will use the same LAI and SAI from 2003-2015 in cycle?
Will it affect the Soil moisture and Surface runoff from simulations?

 

[oleson]

Those websites you referenced are for older versions of the model. For release-cesm2.2.0, please see the following for SP spinup discussion/instructions:

1.5.6. Spinning up the Satellite Phenology Model — ctsm CTSM master documentation

That said, the 1850 spinup is designed to provide initial conditions for a transient simulation 1850-2014. Since you just have atmospheric forcing data for 1991-2015 and want to just run 1980-2020, I would use the 2000_DATM%GSWP3v1_CLM50%SP_SICE_SOCN_MOSART_SGLC_SWAV (I2000) to spinup. You could likely could start from the initial file provided in that compset, but it might be wise to do some spinup before starting your main simulation since your atmospheric forcing is likely to be different from GSWP3V1 and your grid is at finer resolution.

2) The LAI/SAI in this case is a monthly climatology (averaged over 2003-2015). So LAI/SAI will have the same annual cycle each year of your simulation. An alternative is to use the lai streams capability. If you set use_lai_streams = .true. in an SP compset you should get something like this in your lnd_in:

&lai_streams
lai_mapalgo = 'bilinear'
model_year_align_lai = 2001
stream_fldfilename_lai = '/glade/p/cesmdata/cseg/inputdata/lnd/clm2/lai_streams/MODISPFTLAI_0.5x0.5_c140711.nc'
stream_year_first_lai = 2001
stream_year_last_lai = 2013
/

As indicated, the lai data is available for 2001-2013.