6.13. jules_deposition.nml
¶
This file contains options and parameters for modelling of dry deposition of atmospheric trace constituents. It contains a variable number of namelists depending on the required model configuration. The namelist JULES_DEPOSITION
is always required, the namelist JULES_DEPOSITION_SPECIES_SPECIFIC
and one or more instances of the namelist JULES_DEPOSITION_SPECIES
is required if dry deposition has been selected.
Warning
Atmospheric deposition in JULES is still in development. In this version, two options are provided: (1) dry_dep_model
= 1, which implements the existing UKCA interactive gas-phase dry deposition routines in JULES. The parameters are hard-wired in the code and only 4 surface tile configurations are permitted; and (2) dry_dep_model
= 2, which removes the surface tile restrictions and uses namelists to define the various deposition parameters. Deposition parameters specific to a single deposited species are input on JULES_DEPOSITION_SPECIES_SPECIFIC
namelist. There is a separate JULES_DEPOSITION_SPECIES
namelist for each deposited species for deposition parameters common to more than one deposited species. To activate the deposition code: set l_deposition
to TRUE.
6.13.1. JULES_DEPOSITION
namelist members¶
- JULES_DEPOSITION::l_deposition¶
- Type:
logical
- Default:
FALSE
Switch to activate deposition code in JULES.
- TRUE
Model deposition in JULES.
- FALSE
Do not model deposition in JULES.
Only used if l_deposition
= TRUE.
- JULES_DEPOSITION::dry_dep_model¶
- Type:
integer
- Permitted:
1, 2
- Default:
none
Choice for model of dry deposition.
Possible values are:
- Parameterisation based on the interactive dry deposition scheme in the UKCA.
- Parameterisation based on the interactive dry deposition scheme in the UKCA, with the restriction on the allowable surface tile configuration removed.
- JULES_DEPOSITION::dep_h2_soil_scheme¶
- Type:
integer
- Permitted:
1, 2
- Default:
none
Choice for scheme for soil uptake of H2 from the atmosphere.
Possible values are:
- Parameterisation based on Conrad & Seiler uptake scheme in the UKCA.
- Parameterisation based on Paulot et al. scheme.
Note: The Paulot et al. scheme is currently not available in UM-coupled JULES applications.
- JULES_DEPOSITION::l_deposition_flux¶
- Type:
logical
- Default:
FALSE
Switch for calculation of deposition fluxes as opposed to deposition velocities.
- TRUE
Calculate deposition fluxes. This requires that the concentrations of atmopsheric tracer species are provided as prescribed data (see List of supported variables).
- FALSE
Calculate deposition velocities.
- JULES_DEPOSITION::ndry_dep_species¶
- Type:
integer
- Permitted:
>= 1 and <= 200 (ndep_species_max)
- Default:
none
Number of species for which dry deposition is calculated.
- JULES_DEPOSITION::tundra_s_limit¶
- Type:
real
- Default:
none
Latitude of southern limit of tundra (radians). This is used to alter the calculation of deposition of certain species in the tundra region (actually for all points north of this limit). Only used if the list of species (see
dep_species_name_io
) includes one or more of ‘CO’, ‘NO2’, ‘O3’, ‘PAN’, ‘PPAN’, ‘MPAN’ or ‘ONITU’.
- JULES_DEPOSITION::dzl_const¶
- Type:
real
- Default:
none
Constant value for separation of boundary layer levels (m). All layer thicknesses are set to this value. This is used as a simple way to prescribe the layer thicknesses in standalone mode. This value can be overriden by prescribed data - see
JULES_PRESCRIBED
. This can be considered as the representative depth for tracer concentration and the depth over which the deposition flux is removed.
- JULES_DEPOSITION::l_deposition_from_ukca¶
- Type:
logical
- Default:
FALSE
Switch to determine calling routine for the JULES-based interactive deposition routines.
- TRUE
Calls the JULES-based deposition routines from the same UKCA routine ukca_chemistry_ctl (or the equivalents: ukca_chemistry_ctl_BE or ukca_chemistry_ctl_col), which is used to call the UKCA-based interactive deposition routines.
- FALSE
Calls the JULES-based deposition routines from the JULES routine surf_couple_extra.
Note
For JULES standalone applications, the JULES-based deposition routines can only be called from surf_couple_extra() and l_deposition_from_ukca
is false and not enabled. For UM-coupled JULES applications, the JULES-based deposition routines can currently only be called from the UKCA and l_deposition_from_ukca
should be set to true.
(1) Switches that are only available for use in standalone JULES applications.
- JULES_DEPOSITION::l_deposition_gc_corr¶
- Type:
logical
- Default:
FALSE
Switch to use stomatal conductances with or without bare soil evaporation.
- TRUE
Use calculation of stomatal conductance without bare soil evaporation.
- FALSE
Use calculation of stomatal conductance with bare soil evaporation.
(2) For UM-coupled JULES applications, the following switches are set during the run to be equivalent to the corresponding switches in the UKCA (which are set in the UM run_ukca namelist).
- JULES_DEPOSITION::l_ukca_ddep_lev1¶
- Type:
logical
- Default:
FALSE
Switch from the UKCA controlling which atmospheric levels in the boundary layer are used for dry deposition. For UM-coupled JULES applications, the UKCA interactive dry deposition switch (l_ukca_intdd in the run_ukca namelist) needs to be true.
- TRUE
Deposition occurs only from the lowest level in the atmospheric boundary layer.
- FALSE
Deposition occurs from all levels within the atmospheric boundary layer.
- JULES_DEPOSITION::l_ukca_emsdrvn_ch4¶
- Type:
logical
- Default:
FALSE
Switch from the UKCA in which the UKCA chemistry scheme uses methane (CH4) emissions instead of prescribed CH4 surface mole fractions.
- TRUE
UKCA chemistry scheme uses methane (CH4) emissions.
- FALSE
UKCA chemistry scheme uses prescribed CH4 surface mole fractions.
(3) Switches that are only available for UM-coupled JULES applications. The following switches are set during the run to be equivalent to the corresponding switches in the UKCA (which are set in the UM run_ukca namelist).
- JULES_DEPOSITION::l_ukca_ddepo3_ocean¶
- Type:
logical
- Default:
FALSE
Switch from the UKCA to use a mechanistic calculation for deposition of ozone to the ocean from Luhar et al. (2018).
- TRUE
Use the mechanistic calculation of Luhar et al. (2018).
- FALSE
Use the surface resistance term for water provided in rsurf_std_io.
- JULES_DEPOSITION::l_ukca_dry_dep_so2wet¶
- Type:
logical
- Default:
FALSE
Switch from the UKCA to account for surface wetness in the dry deposition for SO2. The calculation uses the parameterisation in Erisman, Pul and Wyers (1994).
- TRUE
Account for surface wetness in the dry deposition for SO2.
- FALSE
Do not account for surface wetness in the dry deposition for SO2.
6.13.2. Notes on the JULES_DEPOSITION
namelist¶
The height of the atmospheric boundary layer is required and is set to a default constant value of 1000 m. This value can be overridden via the namelist variable bl_height
, or can be prescribed (i.e. allowed to vary in time and/or space) by providing bl_height
as prescribed data (see List of supported variables).
The number of model levels in the boundary layer is required and is set to a default balues of 1. This can be overridden via the namelist variable bl_levels
. The number of levels is only used to communicate with the atmospheric model (e.g. UKCA).
The separation of the model levels in the boundary layer is required and is set to a constant value via dzl_const
. The separation can be prescribed (i.e. allowed to vary in time and/or space) by providing level_separation
as prescribed data (see List of supported variables). This can be considered as the representative depth for tracer concentration and the depth over which the deposition flux is removed.
If deposition fluxes (rather than deposition velocities) are to be calculated (see l_deposition_flux
), the concentrations of atmospheric tracer species need to be prescribed (see tracer_field
in List of supported variables).
6.13.3. JULES_DEPOSITION_SPECIES
namelist members¶
This namelist should occur ndry_dep_species
times, with each occurence containing parameters for an atmospheric tracer species that is to be considered in dry deposition.
- JULES_DEPOSITION_SPECIES::dep_species_name_io¶
- Type:
character
- Default:
none
Name of an atmospheric tracer species to be included in deposition modelling.
- JULES_DEPOSITION_SPECIES::dep_species_rmm_io¶
- Type:
real
- Default:
none
Relative molecular mass (g mol-1), as used in the UKCA. It is used in the calculation of the quasi-laminar resistance term (Rb), if no diffusion coefficient is provided.
- JULES_DEPOSITION_SPECIES::diffusion_coeff_io¶
- Type:
real
- Default:
none
Diffusion coefficient (m-2 s-1).
Note
If there is no measured value of the diffusion coefficient for any chemical species in the chemical mechanism, the diffusion coefficient for those species should be set to -1.0. This will be used to indicate that the diffusion coefficient will be calculated from the diffusion coefficient of water and the relative molecular masses of water and the chemical species.
- JULES_DEPOSITION_SPECIES::rsurf_std_io¶
- Type:
real(ntype)
- Default:
none
Standard value of surface resistance for each surface type (s m-1).
Only used if dep_species_name_io
= NO2
, O3
, PAN
, PPAN
, MPAN
or ONITU
. Values provided for other species will be ignored.
- JULES_DEPOSITION_SPECIES::diffusion_corr_io¶
- Type:
real
- Default:
none
Diffusion correction factor for stomatal resistance, accounting for the different diffusivities of water and other species (dimensionless).
Only used if dep_species_name_io
= CO
, NO2
, O3
, PAN
, PPAN
, MPAN
or ONITU
. Values provided for other species will be ignored.
- JULES_DEPOSITION_SPECIES::r_tundra_io¶
- Type:
real
- Default:
none
Surface resistance used in tundra region (s m-1).
Only used if dep_species_name_io
= HNO3
, HONO2
, ISON
and if l_fix_improve_drydep
= true, also for HCl
, HOCl
, HBr
or HOBr
.
- JULES_DEPOSITION_SPECIES::dd_ice_coeff_io¶
- Type:
real(3)
- Default:
none
Coefficients in quadratic function relating dry deposition over ice to temperature.
6.13.4. JULES_DEPOSITION_SPECIES_SPECIFIC
namelist members¶
This namelist is used for deposition parameters specific to a single deposited species. This namelist is used to avoid redundant entries on the JULES_DEPOSITION_SPECIES
namelists.
Deposition parameters specific to dep_species_name_io
= CH4
.
- JULES_DEPOSITION_SPECIES_SPECIFIC::ch4_scaling_io¶
- Type:
real
- Default:
none
Scaling applied to methane soil uptake (dimensionless). (Originally this was used to match the value from the IPCC Third Assessment Report.)
- JULES_DEPOSITION_SPECIES_SPECIFIC::ch4_mml_io¶
- Type:
real
- Default:
none
Factor used in UKCA to convert the methane soil uptake flux in (μg m-2 h-1) to a dry dep velocity (in m s-1). The current value of ch4_mml_io = 3600.0 * 0.016 * 1.0 x 109 * 1.75 x 10-6 = 1.008 x 105, where 0.016 is the relative molecular mass of methane (kg), 1.0 x 109 converts μg to kg, and 1.75 x 10-6 ppmv is the assumed mean global atmospheric volume mixing ratio of methane.
- JULES_DEPOSITION_SPECIES_SPECIFIC::ch4dd_tundra_io¶
- Type:
real(4)
- Default:
none
Coefficients of cubic polynomial relating methane loss for tundra to temperature. Flux is in units of μg (CH4) m-2 s-1.
- JULES_DEPOSITION_SPECIES_SPECIFIC::ch4_up_flux_io¶
- Type:
real(ntype)
- Default:
none
Value of uptake flux for methane for each surface type (μg (CH4) m-2 s-1).
Deposition parameters specific to dep_species_name_io
= H2
.
- JULES_DEPOSITION_SPECIES_SPECIFIC::h2dd_c_io¶
- Type:
real(ntype)
- Default:
none
Constant in quadratic function relating hydrogen deposition to soil moisture (s m-1).
- JULES_DEPOSITION_SPECIES_SPECIFIC::h2dd_m_io¶
- Type:
real(ntype)
- Default:
none
Coefficient of first order term in quadratic function relating hydrogen deposition to soil moisture (s m-1).
- JULES_DEPOSITION_SPECIES_SPECIFIC::h2dd_q_io¶
- Type:
real(ntype)
- Default:
none
Coefficient of second order term in quadratic function relating hydrogen deposition to soil moisture (s m-1).
Deposition parameters specific to dep_species_name_io
= O3
.
- JULES_DEPOSITION_SPECIES_SPECIFIC::cuticle_o3_io¶
- Type:
real
- Default:
none
Constant for calculation of cuticular resistance for ozone (s m-1).
- JULES_DEPOSITION_SPECIES_SPECIFIC::r_wet_soil_o3_io¶
- Type:
real
- Default:
none
Wet soil surface resistance for ozone (s m-1).
6.13.4.1. Example¶
The following gives an example of how you would set up the JULES_DEPOSITION
namelist for atmospheric deposition for a JULES standalone run.
&JULES_DEPOSITION
dep_h2_soil_scheme=1
dry_dep_model=2
dzl_const=50.0
l_deposition=.true.
l_deposition_flux=.false.
l_deposition_from_ukca=.false.
l_deposition_gc_corr=.false.
l_ukca_ddep_lev1=.false.
!!l_ukca_ddepo3_ocean=.false.
!!l_ukca_dry_dep_so2wet=.false.
l_ukca_emsdrvn_ch4=.false.
ndry_dep_species=1
tundra_s_limit=0.866
/
Note: l_deposition_from_ukca
should be false for JULES standalone and true for UM-coupled JULES. l_ukca_ddepo3_ocean
and l_ukca_dry_dep_so2wet
are not available for JULES standalone applications.
The following gives an example of how to set-up the JULES_DEPOSITION_SPECIES
and JULES_DEPOSITION_SPECIES_SPECIFIC
for the standard 5 pft/9 tile configuration for a single chemical species ‘O3’. In general, ndry_dep_species will be greater than 1 and there will be JULES_DEPOSITION_SPECIES
namelists, one for each atmospheric species that is deposited. Some deposition parameters are required for all chemical species, others are species specific and not available (e.g. dd_ice_coeff_io for O3
).
&JULES_DEPOSITION_SPECIES
dep_species_name_io='O3'
dep_species_rmm_io=48.0
diffusion_coeff_io=1.400000e-05
diffusion_corr_io=1.6
r_tundra_io=800.0
rsurf_std_io=200.0,200.0,200.0,200.0,400.0,800.0,2200.0,800.0,2500.0
/
&JULES_DEPOSITION_SPECIES_SPECIFIC
ch4_mml_io=1.008e5
ch4_scaling_io=15.0
ch4_up_flux_io=39.5,50.0,30.0,37.0,27.5,0.0,0.0,27.5,0.0
ch4dd_tundra_io=-4.757e-6,4.0288e-3,-1.13592,106.636
cuticle_o3_io=5000.0
h2dd_c_io=0.00197,0.00197,0.00177,1.2346,0.0001,0.0,0.0,0.0,0.0
h2dd_m_io=-0.00419,-0.00419,-0.00414,-0.472,5*0.0
h2dd_q_io=0.0,0.0,0.0,0.27,5*0.0
r_wet_soil_o3_io=500.0
/