Opened 5 months ago

Last modified 5 months ago

#3166 accepted help

rooting depth

Reported by: awright Owned by: pmcguire
Component: JULES Keywords: rootd_ft_io, rooting depth
Cc: Platform: JASMIN
UM Version:

Description

Hello Patrick,

I need to know the rooting depth of plant functional types in JULES, suite u-al752.
I know from : ​http://jules-lsm.github.io/vn4.9/namelists/pft_params.nml.html that the name of the rooting depth variable is 'rootd_ft_io'.
I can find the parameters for the 'rootd_ft_io' variable here:
/home/users/azin/roses/AWBC4_Std/app/jules/rose-app.conf , which gives the following parameters: rootd_ft_io=3.00,2.00,2.00,1.80,2.00,0.50,0.50,1.00,1.00.

How do I know which rooting depth belongs to which PFT?

Many thanks,

Azin

Change History (3)

comment:1 Changed 5 months ago by pmcguire

  • Status changed from new to accepted

Hi Azin
The scientific settings behind 9-PFT suite u-al752 are described in detail in:
​https://www.geosci-model-dev.net/9/2415/2016/
You can see, for example, that Table 2 has the different settings for rootd for the 9 PFTs, and the numbers that you give from u-al752 match those settings in order. The settings also have column labels for the 9 PFTs, corresponding to:
BET-Tr BET-Te BDT NET NDT C3 C4 ESh DSh

Does this answer your question?
Patrick

Last edited 5 months ago by pmcguire (previous) (diff)

comment:2 Changed 5 months ago by awright

Hello Patrick,

Thank you very much for your reply. I had a look at the information you kindly sent and now I have another question related to the original question.

There are 12 land cover types defined for FLUXNET sites used in u-al752, except for LBA sites:
grass, crop, DBF, MF, DNF, EBF, ENF, Savanna, OSH, CSH, WSA, and Wetland. The acronyms are D: Deciduous, B: Broadleaf, E: Evergreen, F: Forest, M: Mixed, N: Needleleaf, O : Open, C: Closed, SH: Shrubland, W: Woody.

However, in (Harper et al, 2016), (link: w.geosci-model-dev.net/9/2415/2016/) there are 9 PFTs introduced:
BET-Tr, BET-Te, BDT, NET, NDT, C3 grass, C4 grass, ESh, and DSh. The acronyms are B: Broadleaf, E: Evergreen, T: Trees, Tr: Tropical, Te: Temperate, D: Deciduous, N: Needleleaf, and SH: Shrub.

I am not quite sure about the translation of FLUXNET land cover types to the paper PFTs and its implementation in u-al752. For instance, in Table4 of (Harper et al., 2016), site DE-Tha has an ENF land cover, which is translated to 100% NET regarding its PFT. However, for US-Ton site with a WSA land cover, the specified PFT is 33% BDT, 33%C3grass and 33% DSH. BDT, C3 grass and DSH all have different rooting depths.

Is u-al752 coded the same as the suggested in the paper? Do you know where I can check in u-al752 to get the whole picture?

My main aim is to find out the rooting depth for the land cover types. For instance, I want to know the root depth of site ES_Amo which is open shrubland. But there are no examples of that land cover type in the paper. As another example, what is the rooting depth in site US_Ton? Is it an average of the rooting depths of BDT, C3 adn DSH, or the maximum, or something else?

In brief, my question is how to find out the rooting depth of each of the FLUXNET land cover types in u-al752?

Many thanks,

Azin

comment:3 Changed 5 months ago by pmcguire

Hi Azin
Each land-cover type in JULES FLUXNET suite u-al752 does NOT have its own rooting depth defined.
The rooting depth is defined for each PFT for a site. And the land-cover type has certain percentages of each PFT.

You could do a weighted average of the rooting depths for each PFT at the site, but this is probably model-dependent,
since some sites might have spatially-well-mixed PFTs and other sites might have PFTs that are segregated. In the FORTRAN code, the rooting depth-profile is computed separately for each PFT. You might want to study the FORTRAN code. For example:

/group_workspaces/jasmin2/jules/pmcguire/jules_build/jules-vn5.2/src/science/surface/smc_ext_jls_mod.F90 /group_workspaces/jasmin2/jules/pmcguire/jules_build/jules-vn5.2/src/science/surface/physiol_jls_mod.F90 /group_workspaces/jasmin2/jules/pmcguire/jules_build/jules-vn5.2/src/science/surface/root_frac_jls_mod.F90

The Open Shrubland land-cover type is defined in:
~/roses/u-al752/ancil/tilefracs/OSH_fracs9.dat
55% C4 grass, 35% Deciduous Schrubs, 10% Bare Soil

Does this help?
Patrick

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