Opened 7 weeks ago

Last modified 7 weeks ago

#2892 accepted help

Turning TRIFFID off in JULES

Reported by: awright Owned by: pmcguire
Component: JULES Keywords: Jasmin, jules, TRIFFID
Cc: Platform: JASMIN
UM Version:


Hello Patrick,

I have turned TRIFFID off in the JULES suite. I have run the model with no errors. I was wondering if you could also check my methodology so I can be absolutely sure that TRIFFID is off :

1- make a copy of the u-bh383, named u-bh383-TRIFFID
2- vi roses/u-bh383-TRIFFID/app/jules/rose-app.conf

2-1- main TRIFFID switch:
change l_triffid=$L_TRIFFID to l_triffid=false

2-2- look in jules_vegetation.nml (link: for parameters which are not compatible with 'l_triffid=false' mode, and find out how their setting should be (listed below). Then change the settings in rose-app.conf. as below:

In JULES vegetation:
l_veg_compete = false
l_ht_compete = false
l_nitrogen = false
l_trif_eq = false
triffid_period = None , however I kept it as 1 in rose-app.conf.
l_gleaf_fix : does not seem to matter whether true or false, as it only works when TRIFFID is called
l_landuse = false
l_recon = false
frac_min : does not matter what it is set to, although the default is 1.0e-6, because it is Minimum fraction that a PFT is allowed to cover if TRIFFID is used.
frac_seed: Seed fraction for TRIFFID.default value is 0.01.
l_trif_fire = false

In jules_soil_biogeochem:
soil_bgc_model = 1 % means a single-pool model

In pft_params:
canht_ft_io should be None according to the website, however I kept it as canht_ft_io=19.01,19.01,19.01,16.38,16.38,0.79,1.26,1.00,1.00.

lai_io should be None according to the website, however I kept it as lai_io=5.0,5.0,5.0,4.0,4.0,2.0,4.0,1.0,1.0.

Best wishes,


Change History (1)

comment:1 Changed 7 weeks ago by pmcguire

  • Status changed from new to accepted

Hi Azin

I am surprised that you needed to edit the jules_vegetation.nml namelist when you turned the TRIFFID off. Those values for the jules_vegetation namelist probably don't need to be modified.

With your original app\jules\rose-app.conf file, you can just change the lines 135-138, from:

 {%-else %}
              L_TRIFFID = .true.
              L_PHENOL = .true.
              SOIL_BGC_MODEL = 2


 {%-else %}
              L_TRIFFID = .false.
              L_PHENOL = .false.
              SOIL_BGC_MODEL = 1

Those variables from your suite.rc file will be used by the app/jules/rose-app.conf file to turn both the TRIFFID off and the phenology-model off. You probably do need to turn both of those off.

The canopy height values and the leaf-area index values do look like appropriate constant values for the 9 different PFTs.

How do the model output plots compare to when the case when you are using TRIFFID and the phenology model?

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