6.13. pft_params.nml

This file contains a single namelist called JULES_PFTPARM that sets time-and space-invariant parameters for plant functional types.

Note

If the crop model is on (i.e. ncpft > 0), the order of PFTs must be natural PFTs followed by crop PFTs.

6.13.1. JULES_PFTPARM namelist members

This namelist reads the values of parameters for each of the plant functional types (PFTs). These parameters are a function of PFT only. Parameters that also vary with time and location can be prescribed in prescribed_data.nml. Parameters that are only required if the dynamic vegetation (TRIFFID) or phenology sections are requested are read separately in triffid_params.nml. Every member must be given a value for every run.

The files given in the examples directory are a good starting point for setting up any JULES run, and in the majority of cases can be left untouched.

HCTN24 and 30 refer to Hadley Centre technical notes 24 and 30, available from the Met Office Library.

JULES_PFTPARM::canht_ft_io

Type:real(npft) Default:None

The height of each PFT (m), also known as the canopy height.

The value read here is only used if TRIFFID is not active (l_triffid = FALSE).

Note

If TRIFFID is active, canopy height is a prognostic variable and its initial value is read in initial_conditions.nml.

JULES_PFTPARM::lai_io

Type:real(npft) Default:None

The leaf area index (LAI) of each PFT.

The value read here is only used if phenology is not active (l_phenol = FALSE).

Note

If phenology is active, LAI is a prognostic variable and its initial value is read in initial_conditions.nml.

JULES_PFTPARM::c3_io

Type:integer(npft) Default:None

Flag indicating whether PFT is C3 type.

0. Not C3 (i.e. C4).
1. C3.

JULES_PFTPARM::orient_io

Type:integer(npft) Default:None

Flag indicating leaf angle distribution.

0. Spherical.
1. Horizontal.

JULES_PFTPARM::a_wl_io

Type:real(npft) Default:None

Allometric coefficient relating the target woody biomass to the leaf area index (kg carbon m^-2).

JULES_PFTPARM::a_ws_io

Type:real(npft) Default:None

Woody biomass as a multiple of live stem biomass.

JULES_PFTPARM::albsnc_max_io

Type:real(npft) Default:None

Snow-covered albedo for large leaf area index.

Only used if l_snow_albedo = FALSE. See HCTN30 Eq.2.

JULES_PFTPARM::albsnc_min_io

Type:real(npft) Default:None

Snow-covered albedo for zero leaf area index.

Only used if l_snow_albedo = FALSE. See HCTN30 Eq.2.

JULES_PFTPARM::albsnf_max_io

Type:real(npft) Default:None

Snow-free albedo for large LAI.

Only used if l_spec_albedo = FALSE. See HCTN30 Eq.1.

JULES_PFTPARM::albsnf_maxu_io

Type:real(npft) Default:None

Upper bound for the snow-free albedo for large LAI, when scaled to match input obs.

Only used if l_spec_albedo = FALSE and l_albedo_obs = TRUE.

JULES_PFTPARM::albsnf_maxl_io

Type:real(npft) Default:None

Lower bound for the snow-free albedo for large LAI, when scaled to match input obs.

Only used if l_spec_albedo = FALSE and l_albedo_obs = TRUE.

JULES_PFTPARM::alpha_io

Type:real(npft) Default:None

Quantum efficiency (mol CO₂ per mol PAR photons).

JULES_PFTPARM::alnir_io

Type:real(npft) Default:None

Leaf reflection coefficient for NIR. See HCTN30 Table 3.

Used when l_spec_albedo = TRUE.

JULES_PFTPARM::alniru_io

Type:real(npft) Default:None

Upper limit for the leaf reflection coefficient for NIR, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::alnirl_io

Type:real(npft) Default:None

Lower limit for the leaf reflection coefficient for NIR, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::alpar_io

Type:real(npft) Default:None

Leaf reflection coefficient for VIS (photosyntehtically active radiation). See HCTN30 Table 3.

Used when l_spec_albedo = TRUE.

JULES_PFTPARM::alparu_io

Type:real(npft) Default:None

Upper limit for the leaf reflection coefficient for VIS, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::alparl_io

Type:real(npft) Default:None

Lower limit for the leaf reflection coefficient for VIS, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::b_wl_io

Type:real(npft) Default:None

Allometric exponent relating the target woody biomass to the leaf area index. This is 5/3 in HCTN24 Eq.8.

JULES_PFTPARM::catch0_io

Type:real(npft) Default:None

Minimum canopy capacity (kg m^-2).

This is the minimum amount of water that can be held on the canopy. See HCTN30 p7.

JULES_PFTPARM::dcatch_dlai_io

Type:real(npft) Default:None

Rate of change of canopy capacity with LAI (kg m^-2).

Canopy capacity is calculated as catch0 + dcatch_dlai*lai. See HCTN30 p7.

JULES_PFTPARM::dgl_dm_io

Type:real(npft) Default:None

Rate of change of leaf turnover rate with moisture availability.

JULES_PFTPARM::dgl_dt_io

Type:real(npft) Default:None

Rate of change of leaf turnover rate with temperature (K^-1).

This is 9 in HCTN24 Eq.10.

JULES_PFTPARM::dqcrit_io

Type:real(npft) Default:None

Critical humidity deficit (kg H₂O per kg air).

JULES_PFTPARM::dz0v_dh_io

Type:real(npft) Default:None

Rate of change of vegetation roughness length for momentum with height.

Roughness length is calculated as dz0v_dh * canht_ft. See HCTN30 p5.

JULES_PFTPARM::eta_sl_io

Type:real(npft) Default:None

Live stemwood coefficient (kg C/m/LAI).

JULES_PFTPARM::fd_io

Type:real(npft) Default:None

Scale factor for dark respiration. See HCTN 24 Eq. 56.

JULES_PFTPARM::fsmc_of_io

Type:real(npft) Default:None

Moisture availability below which leaves are dropped.

JULES_PFTPARM::f0_io

Type:real(npft) Default:None

CI / CA for DQ = 0. See HCTN 24 Eq. 32.

JULES_PFTPARM::g_leaf_0_io

Type:real(npft) Default:None

Minimum turnover rate for leaves (/360days).

JULES_PFTPARM::glmin_io

Type:real(npft) Default:None

Minimum leaf conductance for H₂O (m s^-1).

JULES_PFTPARM::infil_f_io

Type:real(npft) Default:None

Infiltration enhancement factor.

The maximum infiltration rate defined by the soil parameters for the whole gridbox may be modified for each PFT to account for tile-dependent factors, such as macro-pores related to vegetation roots.

See HCTN30 p14 for full details.

JULES_PFTPARM::kext_io

Type:real(npft) Default:None

Light extinction coefficient - used with Beer’s Law for light absorption through tile canopies. See HCTN30 Eq.3.

JULES_PFTPARM::kpar_io

Type:real(npft) Default:None

PAR Extinction coefficient (m² leaf / m² ground).

JULES_PFTPARM::neff_io

Type:real(npft) Default:None

Scale factor relating V_cmax with leaf nitrogen concentration. See HCTN 24 Eq. 51.

Only used if l_trait_phys = F.

JULES_PFTPARM::nl0_io

Type:real(npft) Default:None

Top leaf nitrogen concentration (kg N/kg C).

Only used if l_trait_phys = F.

JULES_PFTPARM::nr_nl_io

Type:real(npft) Default:None

Ratio of root nitrogen concentration to leaf nitrogen concentration.

JULES_PFTPARM::ns_nl_io

Type:real(npft) Default:None

Ratio of stem nitrogen concentration to leaf nitrogen concentration.

JULES_PFTPARM::omega_io

Type:real(npft) Default:None

Leaf scattering coefficient for PAR.

Used when l_spec_albedo = TRUE.

JULES_PFTPARM::omegau_io

Type:real(npft) Default:None

Upper limit for the leaf scattering coefficient for PAR, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::omegal_io

Type:real(npft) Default:None

Lower limit for the leaf scattering coefficient for PAR, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::omnir_io

Type:real(npft) Default:None

Leaf scattering coefficient for NIR.

Used when l_spec_albedo = TRUE.

JULES_PFTPARM::omniru_io

Type:real(npft) Default:None

Upper limit for the leaf scattering coefficient for NIR, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::omnirl_io

Type:real(npft) Default:None

Lower limit for the leaf scattering coefficient for NIR, when l_albedo_obs = TRUE and l_spec_albedo = TRUE.

JULES_PFTPARM::r_grow_io

Type:real(npft) Default:None

Growth respiration fraction.

JULES_PFTPARM::rootd_ft_io

Type:real(npft) Default:None

Root depth (m).

An exponential distribution with depth is assumed, with e-folding depth rootd_ft. Note that this means that generally some of the roots exist at depths greater than rootd_ft. See HCTN30 Eq.32.

JULES_PFTPARM::sigl_io

Type:real(npft) Default:None

Specific density of leaf carbon (kg C/m² leaf).

Only used if l_trait_phys = F.

JULES_PFTPARM::tleaf_of_io

Type:real(npft) Default:None

Temperature below which leaves are dropped (K).

JULES_PFTPARM::tlow_io

Type:real(npft) Default:None

Lower temperature for photosynthesis (deg C).

JULES_PFTPARM::tupp_io

Type:real(npft) Default:None

Upper temperature for photosynthesis (deg C).

JULES_PFTPARM::emis_pft_io

Type:real(npft) Default:None

Surface emissivity.

JULES_PFTPARM::z0hm_pft_io

Type:real(npft) Default:None

Ratio of the roughness length for heat to the roughness length for momentum.

This is generally assumed to be 0.1. See HCTN30 p6. Note that this is the ratio of the roughness length for heat to that for momentum. It does not alter the roughness length for momentum, which is calculated using canht_ft_io and dz0v_dh_io.

JULES_PFTPARM::z0hm_classic_pft_io

Type:real(npft) Default:None

Ratio of the roughness length for heat to the roughness length for momentum for the CLASSIC aerosol scheme only.

Note

This makes no difference to the model when running standalone, and is only required to keep the standalone and UM interfaces consistent.

JULES_PFTPARM::fl_o3_ct_io

Type:real(npft) Default:None

Critical flux of O3 to vegetation (mmol m^-2 s^-1).

JULES_PFTPARM::dfp_dcuo_io

Type:real(npft) Default:None

Fractional reduction of photosynthesis with the cumulative uptake of O3 by leaves (mmol m^-2).

JULES_PFTPARM::ief_io

Type:real(npft) Default:None

Isoprene Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::tef_io

Type:real(npft) Default:None

Monoterpene Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::mef_io

Type:real(npft) Default:None

Methanol Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::aef_io

Type:real(npft) Default:None

Acetone Emission Factor (μg g^-1 h^-1).

JULES_PFTPARM::ci_st_io

Tybe:real(npft) Default:None

Leaf-internal CO₂concentration at standard conditions (Pa),

Note

Standard conditions are: T = 303.15K, p = 1013.25 hPa, atmospheric CO₂ = 370 ppmv, PAR = 1000 μmol m^-2 s^-1.

JULES_PFTPARM::gpp_st_io

Tybe:real(npft) Default:None

Gross primary production (GPP) at standard conditions (kgC m^-2 s^-1),

Note

Standard conditions are: T = 303.15K, p = 1013.25 hPa, atmospheric CO₂ = 370 ppmv, PAR = 1000 μmol m^-2 s^-1.

JULES_PFTPARM::nmass_io

Type:real(npft) Default:None

Top leaf nitrogen content per unit mass (kgN kgLeaf^-1).

Only used if l_trait_phys = T.

JULES_PFTPARM::lma_io

Type:real(npft) Default:None

Leaf mass per unit area (kgLeaf m^-2).

Only used if l_trait_phys = T.

JULES_PFTPARM::vint_io

Type:real(npft) Default:None

There is a linear relationship between Vcmax and Narea. Previously Vcmax was calculated as the product of nl0 and neff.

This is now replaced by a linear regression based on data reported in Kattge et al. 2009. Vint is the y-intercept, vsl is the slope.

Units: μmol CO2 m^-2 s^-1.

Only used if l_trait_phys = T.

JULES_PFTPARM::vsl_io

Type:real(npft) Default:None

Slope in the linear regression between Vcmax and Narea.

Units: μmol CO2 gN^-1 s^-1.

Only used if l_trait_phys = T.

JULES_PFTPARM::kn_io

Type:real(npft) Default:0.78

Decay of nitrogen through the canopy.

This is changed for trees and shrubs (data not available for grasses so remains at the previous value of 0.78).

Note

This was previously set in the subroutine src/science/params/surf_param.F90.

JULES_PFTPARM::q10_leaf_io

Type:real(npft) Default:2.0

Q10 factor for plant respiration.

See Cox et al. (1999) Eq. 66.

Note

Was previously a single parameter but now can have PFT-dependent values.