6.25. nveg_params.nml

This file contains a namelist called JULES_NVEGPARM that sets time-invariant parameters for non-vegetation surface types for the JULES land surface model.

6.25.1. JULES_NVEGPARM namelist members

This namelist reads the values of parameters for each of the non-vegetation surface types if the JULES land surface model is being used. These parameters are a function of surface type only. All parameters must be defined for any configuration.

HCTN30 refers to Hadley Centre technical note 30, available from the Met Office Library.

JULES_NVEGPARM::albsnc_nvg_io

Type:

real(nnvg)

Default:

None

Snow-covered albedo.

Only used if l_snow_albedo = FALSE. See HCTN30 Table 1.

JULES_NVEGPARM::albsnf_nvg_io

Type:

real(nnvg)

Default:

None

Snow-free albedo.

See HCTN30 Table 1.

A bare soil snow-free albedo of -1.0 indicates that it is supplied by an ancillary field.

JULES_NVEGPARM::albsnf_nvgu_io

Type:

real(nnvg)

Default:

None

Upper limit on snow-free albedo, when l_albedo_obs = TRUE.

JULES_NVEGPARM::albsnf_nvgl_io

Type:

real(nnvg)

Default:

None

Lower limit on snow-free albedo, when l_albedo_obs = TRUE.

JULES_NVEGPARM::catch_nvg_io

Type:

real(nnvg)

Default:

None

Capacity for water (kg m^-2).

See HCTN30 p7.

JULES_NVEGPARM::gs_nvg_io

Type:

real(nnvg)

Default:

None

Surface conductance (m s^-1).

See HCTN30 p7. Soil conductance is modified by soil moisture according to HCTN30 Eq35.

JULES_NVEGPARM::infil_nvg_io

Type:

real(nnvg)

Default:

None

Infiltration enhancement factor.

The maximum infiltration rate defined by the soil parameters for the whole gridbox may be modified for each surface tile to account for tile-dependent factors.

See HCTN30 p14 for full details.

JULES_NVEGPARM::z0_nvg_io

Type:

real(nnvg)

Default:

None

Roughness length for momentum (m).

See HCTN30 Table 4.

JULES_NVEGPARM::ch_nvg_io

Type:

real(nnvg)

Default:

None

Heat capacity of this surface type (J K^-1 m^-2).

Used only if can_model is 3 or 4.

JULES_NVEGPARM::vf_nvg_io

Type:

real(nnvg)

Default:

None

Fractional coverage of non-vegetation “canopy”.

Typically set to 0.0 (conductively coupled), but value of 1.0 (radiatively coupled) used if surface tile should have a heat capacity in conjunction with can_model options 3 or 4.

Note

If l_moruses_storage = T, then for the roof coupling: 0 = uncoupled

JULES_NVEGPARM::emis_nvg_io

Type:

real(nnvg)

Default:

None

Surface emissivity of non-vegetated surfaces.

JULES_NVEGPARM::z0hm_nvg_io

Type:

real(nnvg)

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 given by z0_nvg_io.

JULES_NVEGPARM::z0hm_classic_nvg_io

Type:

real(nnvg)

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.