6.12. jules_soil_ecosse.nml
¶
This file sets options and parameters for the ECOSSE model of soil biogeochemistry. It is used only if the ECOSSE model is chosen (soil_bgc_model
= 3).
Warning
The ECOSSE model in JULES is still in development and is not fully functional in this version. The code is included to allow further development. Users should not try to use ECOSSE.
6.12.1. JULES_SOIL_ECOSSE
namelist members¶

JULES_SOIL_ECOSSE::
l_soil_n
¶ Type: logical Default: T Switch to include soil nitrogen in ECOSSE.
 TRUE
 Model soil carbon and nitrogen.
 FALSE
 Model only soil carbon.

JULES_SOIL_ECOSSE::
l_match_layers
¶ Type: logical Default: T Switch to match ECOSSE soil C and N layers to those for soil moisture.
 TRUE
 Use the same layering as for soil moisture. The number of soil carbon layers will equal
sm_levels
, with layer thicknesses given bydzsoil_io
.  FALSE
 The number of layers will be specified by
dim_cslayer
and the thicknesses bydz_soilc_io
.

JULES_SOIL_ECOSSE::
dim_cslayer
¶ Type: integer Permitted: >= 1 Default: None The number of ECOSSE soil carbon layers. Not used if
l_match_layers
= TRUE. Despite the similar name, this parameter is unrelated tosclayer_dim_name
.

JULES_SOIL_ECOSSE::
dz_soilc_io
¶ Type: real(dim_cslayer) Permitted: > 0 Default: None Thicknesses of the ECOSSE soil carbon layers (m). Not used if
l_match_layers
= TRUE. In most cases the total depth must equal that of the soil moisture layers (seedzsoil_io
). The exception is the case of a single layer, bulk model (dim_cslayer
= 1), for which dz_soilc(1) is interpreted as the representative or averaging depth for the bulk layer (e.g. the temperature of the bulk model is taken as the average over this depth).

JULES_SOIL_ECOSSE::
dt_soilc
¶ Type: REAL Permitted: >= timestep_len
Default: timestep_len
The timestep length for ECOSSE (seconds). The main JULES timestep length
timestep_len
must be a multiple of this timestep length, so that ECOSSE is called on JULES timesteps. The TRIFFID timestep lengthtriffid_period
(converted to seconds) must also be a multiple of the ECOSSE timestep length.

JULES_SOIL_ECOSSE::
l_driver_ave
¶ Type: logical Default: T Switch controlling the averaging of the physical driving variables that are input to ECOSSE (e.g. soil temperature).
 TRUE
 Average the driving variables over the ECOSSE timestep length.
 FALSE
 Use instantaneous values of the driving variables at the time when ECOSSE is called.

JULES_SOIL_ECOSSE::
plant_input_profile
¶ Type: INTEGER Permitted: 1 or 2 Default: 1 Switch for the vertical distribution of litterfall inputs of C and N to the soil.
Possible values are:
 Fraction
pi_sfc_frac
of inputs are distributed uniformly in a surface layer of depthpi_sfc_depth
, the remainder are distributed according to the distribution of roots.  Inputs decrease exponentially with depth with decay constant
tau_lit
.

JULES_SOIL_ECOSSE::
pi_sfc_frac
¶ Type: REAL Default: 0.3 Fraction of plant litterfall that is added to the surface soil layer of depth
pi_sfc_depth
. Only used ifplant_input_profile
= 1.

JULES_SOIL_ECOSSE::
pi_sfc_depth
¶ Type: REAL Default: 0.1 Depth of soil over which fraction
pi_sfc_frac
of plant litterfall is added (m). Only used ifplant_input_profile
= 1.

JULES_SOIL_ECOSSE::
temp_modifier
¶ Type: INTEGER Permitted: 1 or 2 Default: 2 Switch for the form of the temperature rate modifier for decomposition.
 Use a Q10 approach.
 Use the RothC form of the modifier.

JULES_SOIL_ECOSSE::
water_modifier
¶ type: INTEGER permitted: 1 or 2 default: 2 Switch for the form of the water rate modifier for decomposition and nitrification.
 Use the JULES form of the modifier.
 Use the RothC form of the modifier.

JULES_SOIL_ECOSSE::
decomp_rate
¶ Type: REAL(4) Default: 3.22e7, 9.65e9, 2.12e8, 6.43e10 Rate constant for decomposition of each soil carbon pool (s^{1}).
Note that these default values are also those for use with the RothC model (
kaps_roth
).

JULES_SOIL_ECOSSE::
decomp_ph_rate_min
¶ Type: REAL Default: 0.2 Minimum allowed value of pH rate modifier for decomposition.

JULES_SOIL_ECOSSE::
decomp_ph_min
¶ Type: REAL Permitted: decomp_ph_min <= decomp_ph_max Default: 1.0 Soil pH below which rate of decomposition is minimum.

JULES_SOIL_ECOSSE::
decomp_ph_max
¶ Type: REAL Permitted: decomp_ph_max >= decomp_ph_min Default: 4.5 Soil pH above which rate of decomposition is maximum.

JULES_SOIL_ECOSSE::
decomp_temp_coeff_rothc
¶ Type: REAL(3) Default: 47.9, 106.0, 18.3 Constants in the RothC from of the decomposition temperature modifier (
temp_modifier
= 2).Note that these default values are also those harwired in the code for use with the RothC model (
soil_bgc_model
= 2,l_q10
= F ).

JULES_SOIL_ECOSSE::
decomp_wrate_min_rothc
¶ Type: REAL Default: 0.2 Minimum allowed value of the water rate modifier for decomposition when the RothC form is used (
water_modifier
= 2).

JULES_SOIL_ECOSSE::
decomp_wrate_min_jules
¶ Type: REAL Default: 0.2 Minimum allowed value of the water rate modifier for decomposition when the JULES form is used (
water_modifier
= 1).Note that this default value is also that harwired in the code for use with the RothC model (
soil_bgc_model
= 2).
Parameters for ECOSSE that are only used if soil N is included (l_soil_n
= TRUE).

JULES_SOIL_ECOSSE::
l_decomp_slow
¶ Type: logical Default: T Switch controlling how lack of nitrogen affects soil decomposition.
 TRUE
 Reduce the decomposition rate.
 FALSE
 Reduce the efficiency of decomposition, so that decomposition results in increased production of CO_{2} and decreased production of further soil C. This is the approach used in the standalone version of ECOSSE.

JULES_SOIL_ECOSSE::
depo_nit_frac
¶ Type: REAL Permitted: 0 <= depo_nit_frac <= 1 Default: 1.0 The fraction of nitrogen deposition that is aded to the soil nitrate pool. The complement is aded to the ammonium pool.

JULES_SOIL_ECOSSE::
bacteria_min_frac
¶ Type: REAL Permitted: 0 <= bacteria_min_frac <= 1 Default: 0.2 The minimum fraction of the decomposer community that are bacteria.

JULES_SOIL_ECOSSE::
bacteria_max_frac
¶ Type: REAL Permitted: bacteria_min_frac <= bacteria_max_frac <= 1 Default: 0.5 The maximum fraction of the decomposer community that are bacteria.

JULES_SOIL_ECOSSE::
bacteria_min_frac_pH
¶ Type: REAL Default: 4.0 The soil pH at or below which the fraction of bacteria is at a minimum.

JULES_SOIL_ECOSSE::
bacteria_max_frac_pH
¶ Type: REAL Permitted: bacteria_min_frac_pH <= bacteria_max_frac_pH Default: 5.5 The soil pH at or above which the fraction of bacteria is at a maximum.

JULES_SOIL_ECOSSE::
cn_bacteria
¶ Type: REAL Default: 5.5 The C:N ratio of soil bacteria.

JULES_SOIL_ECOSSE::
cn_fungi
¶ Type: REAL Default: 5.5 The C:N ratio of soil fungi.

JULES_SOIL_ECOSSE::
depth_nitrif
¶ Type: REAL Default: 0.25 Greatest depth at which nitrification and denitrification are allowed (m).

JULES_SOIL_ECOSSE::
nitrif_rate
¶ Type: REAL Default: 9.921e7 Rate constant for nitrification (s^{1}).

JULES_SOIL_ECOSSE::
nitrif_wrate_min
¶ Type: REAL Default: 0.6 Minimum allowed value of the water rate modifier for nitrification when RothC form is used. Only used if
water_modifier
= 2.).

JULES_SOIL_ECOSSE::
nitrif_max_factor
¶ Type: REAL Default: 0.1 Shape factor in rate modifier for nitrification (kg m^{3}).

JULES_SOIL_ECOSSE::
nitrif_frac_n2o_fc
¶ Type: REAL Permitted: 0 <= nitrif_frac_n2o_fc <= 1 Default: 0.02 Fraction of nitrification lost as N_{2}O by partial nitrification at field capacity.

JULES_SOIL_ECOSSE::
nitrif_frac_gas
¶ Type: REAL Permitted: 0 <= nitrif_frac_gas <= 1 Default: 0.02 Fraction of nitrification lost as gas through full nitrification.

JULES_SOIL_ECOSSE::
nitrif_frac_no
¶ Type: REAL Permitted: 0 <= nitrif_frac_no <= 1 Default: 0.4 Fraction of nitrification gas loss through full nitrification that is NO.

JULES_SOIL_ECOSSE::
denit50
¶ Type: REAL Default: 0.033 Amount of nitrate at which denitrification rate is 50% of the potential rate (kg m^{3}).

JULES_SOIL_ECOSSE::
denit_bio_factor
¶ Type: REAL Default: 0.005 Factor in denitrification calculation to convert flux of CO_{2} into a representation of biological activity (m^{2} kg^{1}).

JULES_SOIL_ECOSSE::
denit_frac_n2_fc
¶ Type: REAL Permitted: 0 <= denit_frac_n2_fc <= 1 Default: 0.55 Proportion of denitrified N that becomes N_{2} when soil moisture is at field capacity.

JULES_SOIL_ECOSSE::
denit_nitrate_equal
¶ Type: REAL Default: 0.4 Amount of N in soil nitrate at which denitrified N is released as equal amounts of N_{2} and N_{2`O (kg m:sup:}3`).

JULES_SOIL_ECOSSE::
denit_water_coeff
¶ Type: REAL(3) Default: 0.62, 0.38, 1.74 Constants describing water modifier for denitrification.

JULES_SOIL_ECOSSE::
amm_leach_min
¶ Type: REAL Default: 0.02 Minimum allowed amount of N in soil ammonium after leaching (kg m^{3}).

JULES_SOIL_ECOSSE::
n_inorg_max_conc
¶ Type: REAL Default: 1.0 Maximumallowed concentration of inorganic N in a layer (kg m^{3}). A value less than zero means no maximum concentration is imposed.