6.7. ancillaries.nml

This file sets up the values for tile fractional coverage, soil properties, PDM and TOPMODEL parameters and agricultural fraction. It contains six namelists - JULES_FRAC, JULES_SOIL_PARAM, JULES_SOIL_PROPS, JULES_PDM, JULES_TOP and JULES_AGRIC.

6.7.1. JULES_FRAC namelist members

This namelist specifies the fraction of the land area in each gridbox that is covered by each of the surface types. If l_veg_compete = TRUE, then the fraction of each surface type is modelled and the initial state should be specified in JULES_INITIAL. In all other cases, it must be read here.

Note that all land points must be either soil points (indicated by values > 0 of the saturated soil moisture content), or land ice points (indicated by the fractional coverage of the ice surface type - if used - being one). The fractional cover of the ice surface type in each gridbox must be either zero or one - there cannot be partial coverage of ice within a gridbox.

If using either URBAN-2T or MORUSES then the total urban fraction should be entered in the urban_canyon or urban tile, whichever is specified. This is partitioned into canyon and roof fractions using the canyon fraction (W/R). The canyon fraction is set in urban.nml and can either be prescribed by the user or calculated by an empirical formula.

JULES_FRAC::file

Type:character Default:None

The name of the file to read surface type fractional coverage data from.

JULES_FRAC::frac_name

Type:character Default:None

The name of the variable containing the surface type fractional coverage data.

Note

This is only used for NetCDF files. For ASCII files, the surface type fractional coverage data is expected to be the first (ideally only) variable in the file.

In the file, the variable must have a levels (z) dimension of size ntype called type_dim_name, and should not have a time dimension.

6.7.2. JULES_SOIL_PARAM namelist members

This namelist is responsible for setting soil parameters that are not spacially varying.

JULES_SOIL_PARAM::zsmc

Type:real Permitted:> 0 Default:1.0

If a depth-averaged soil moisture diagnostic is requested, the average is calculated from the surface to this depth (m).

JULES_SOIL_PARAM::zst

Type:real Permitted:> 0 Default:1.0

If a depth-averaged soil temperature diagnostic is requested, the average is calculated from the surface to this depth (m).

JULES_SOIL_PARAM::confrac

Type:real Permitted:0 <= confrac <= 1 Default:0.3

The fraction of the gridbox covered by convective precipitation.

JULES_SOIL_PARAM::dzsoil_io

Type:real(sm_levels) Default:None

The soil layer depths (m), starting with the uppermost layer.

Note that the soil layer depths (and hence the total soil depth) are constant across the domain.

In all the examples, JULES uses layer depths of 0.1, 0.25, 0.65 and 2.0m, giving a total depth of 3.0m. It is recommended that this is used unless there is good reason not to.

6.7.3. JULES_SOIL_PROPS namelist members

This namelist specifies how spacially varying soil properties should be set.

JULES_SOIL_PROPS::const_z

Type:logical Default:F

Switch indicating if soil properties are to be uniform with depth.

TRUE

Soil characteristics do not vary with depth.

FALSE

Soil characteristics vary with depth.

JULES_SOIL_PROPS::file

Type:character Default:None

The file to read soil properties from.

If use_file is FALSE for every variable, this will not be used.

This file name can use variable name templating.

JULES_SOIL_PROPS::nvars

Type:integer Permitted:>= 0 Default:0

The number of soil property variables that will be provided. At present, all variables are required for all runs.

JULES_SOIL_PROPS::var

Type:character(nvars) Default:None

List of soil variable names as recognised by JULES (see List of soil parameters). Names are case sensitive.

Note

For ASCII files, variable names must be in the order they appear in the file.

JULES_SOIL_PROPS::use_file

Type:logical(nvars) Default:T

For each JULES variable specified in var, this indicates if it should be read from the specified file or whether a constant value is to be used.

TRUE

The variable will be read from the file.

FALSE

The variable will be set to a constant value everywhere using const_val below.

JULES_SOIL_PROPS::var_name

Type:character(nvars) Default:None

For each JULES variable specified in var where use_file = TRUE, this is the name of the variable in the file containing the data.

This is not used for variables where use_file = FALSE, but a placeholder must still be given.

Note

For ASCII files, this is not used - only the order in the file matters, as described above.

JULES_SOIL_PROPS::tpl_name

Type:character(nvars) Default:None

For each JULES variable specified in var, this is the string to substitute into the file name in place of the variable name substitution string.

If the file name does not use variable name templating, this is not used.

JULES_SOIL_PROPS::const_val

Type:real(nvars) Default:None

For each JULES variable specified in var where use_file = FALSE, this is a constant value that the variable will be set to at every point in every layer.

This is not used for variables where use_file = TRUE, but a placeholder must still be given.

6.7.3.1. List of soil parameters

If const_z = FALSE, variables read from file must have a levels (z) dimension of size sm_levels called soil_dim_name.

If const_z = TRUE, variables read from file must have no levels dimension.

In both cases, the variables must have no time dimension. Some examples of the setup of soil properties can be found in the examples directory.

Name	Description
albsoil	Soil albedo. A single (averaged) waveband is used.
b	Exponent in soil hydraulic characteristics.
hcap	Dry heat capacity (J m-3 K-1).
hcon	Dry thermal conductivity (W m-1 K-1).
satcon	Hydraulic conductivity at saturation (kg m-2 s-1).
sathh	If l_vg_soil = TRUE (using van Genuchten model), sathh = 1 / α (m-1), where α is a parameter of the van Genuchten model. If l_vg_soil = FALSE (using Brooks and Corey model), sathh is the absolute value of the soil matric suction at saturation (m). The suction at saturation is generally less than zero, but JULES uses the absolute value.
sm_crit	Volumetric soil moisture content at the critical point (m3 water per m3 soil). The critical point is that at which soil moisture stress starts to restrict transpiration.
sm_sat	Volumetric soil moisture content at saturation (m3 water per m3 soil). Note This field is used to distinguish between soil points and land ice points. sm_sat > 0 indicates a soil point.
sm_wilt	Volumetric soil moisture content at the wilting point (m3 water per m3 soil). The wilting point is that at which soil moisture stress completely prevents transpiration.

6.7.4. JULES_PDM namelist members

This namelist reads parameter values for the PDM-type parameterisation of surface runoff. The values are only used if l_pdm = TRUE. These parameters are held constant across the model domain. For further details of PDM, see references under l_pdm.

JULES_PDM::dz_pdm

Type:real Default:1.0

The depth of soil considered by PDM (m).

A value of ~1m can be used.

JULES_PDM::b_pdm

Type:real Default:1.0

Shape factor for the pdf.

6.7.5. JULES_TOP namelist members

This namelist reads parameter values for the TOPMODEL-type parameterisation of runoff. The values are only used if l_top = TRUE. The description below is very brief. For further details, see the references under l_top.

JULES_TOP::zw_max

Type:real Default:15.0

The maximum allowed depth to the water table (m).

This is the depth to the bottom of an additional layer below the sm_levels soil layers and hence should be set to a value greater than SUM(dzsoil).

Values of 10 to 15m have been used.

JULES_TOP::ti_max

Type:real Default:10.0

The maximum possible value of the topographic index.

A value of 10 has been used successfully.

JULES_TOP::ti_wetl

Type:real Default:2.0

A calibration parameter used in the calculation of the wetland fraction.

It is used to increment the “critical” value of the topographic index that is used to calculate the saturated fraction of the gridbox. It excludes locations with large values of the topographic index from the wetland fraction.

See Gedney and Cox (2003).

A value of 2 has been used.

Members used to set up spacially varying properties

JULES_TOP::file

Type:character Default:None

The file to read TOPMODEL properties from.

If use_file is FALSE for every variable, this will not be used.

This file name can use variable name templating.

JULES_TOP::nvars

Type:integer Permitted:>= 0 Default:0

The number of TOPMODEL property variables that will be provided. At present, all variables are required for runs using TOPMODEL.

JULES_TOP::var

Type:character(nvars) Default:None

List of TOPMODEL variable names as recognised by JULES (see List of TOPMODEL parameters). Names are case sensitive.

Note

For ASCII files, variable names must be in the order they appear in the file.

JULES_TOP::use_file

Type:logical(nvars) Default:T

For each JULES variable specified in var, this indicates if it should be read from the specified file or whether a constant value is to be used.

TRUE

The variable will be read from the file.

FALSE

The variable will be set to a constant value everywhere using const_val below.

JULES_TOP::var_name

Type:character(nvars) Default:None

For each JULES variable specified in var where use_file = TRUE, this is the name of the variable in the file containing the data.

This is not used for variables where use_file = FALSE, but a placeholder must still be given.

Note

For ASCII files, this is not used - only the order in the file matters, as described above.

JULES_TOP::tpl_name

Type:character(nvars) Default:None

For each JULES variable specified in var, this is the string to substitute into the file name in place of the variable name substitution string.

If the file name does not use variable name templating, this is not used.

JULES_TOP::const_val

Type:real(nvars) Default:None

For each JULES variable specified in var where use_file = FALSE, this is a constant value that the variable will be set to at every point in every layer.

This is not used for variables where use_file = TRUE, but a placeholder must still be given.

6.7.5.1. List of TOPMODEL parameters

All of the TOPMODEL variables listed below are expected to have no levels (z) dimension and no time dimension.

Name	Description
fexp	Decay factor describing how the saturated hydraulic conductivity decreases with depth below the standard soil column (m-1).
ti_mean	Mean value of the topographic index in each gridbox.
ti_sig	Standard deviation of the topographic index in each gridbox.

6.7.6. JULES_AGRIC namelist members

If the TRIFFID vegetation model is used, the fractional area of agricultural land in each gridbox is specified using this namelist. Otherwise, the values in this namelist are not used.

JULES_AGRIC::zero_agric

Type:logical Default:T

Switch used to simplify the initialisation of agricultural fraction.

TRUE

Set agricultural fraction at all points to zero.

FALSE

Set agricultural fraction using specified data.

Used if zero_agric = FALSE and the input grid consists of a single location

JULES_AGRIC::frac_agr

Type:real Default:None

The agricultural fraction for the single location.

Used if zero_agric = FALSE and the input grid consists of more than one location

JULES_AGRIC::file

Type:character Default:None

The name of the file to read agricultural fraction data from.

JULES_AGRIC::agric_name

Type:character Default:None

The name of the variable containing the agricultural fraction data.

In the file, the variable must have no levels (z) dimension and no time dimension.