Idealized Moist Physics
The idealized_moist_phys_nml
only ever needs to be specified if
idealized_moist_model = True
in atmosphere_nml
.
It contains options which specify the various modules associated with Isca’s moist physics configurations and is
described on Isca's website. Isca also gives
numerous example scripts
using the idealized_moist_phys_nml
namelist.
Some of the most common options are described below:
Options
convection_scheme
string There are 4 choices of convection schemes, as well as no convection, in Isca:
SIMPLE_BETTS_CONV
- Use Frierson Quasi-Equilibrium convection scheme [Frierson2007]. If this is selected, thelscale_cond_nml
andqe_moist_convection_nml
namelists needs to be specified.FULL_BETTS_MILLER_CONV
- Use the Betts-Miller convection scheme [Betts1986], [BettsMiller1986]. If this is selected, thelscale_cond_nml
andbetts_miller_nml
namelists needs to be specified.RAS
- Use the relaxed Arakawa Schubert convection scheme [Moorthi1992]. If this is selected, thelscale_cond_nml
andras_nml
namelists needs to be specified.DRY
- Use the dry convection scheme [Schneider2006]. This module needs thedry_convection_nml
namelist specified.NONE
- Use no convection scheme.UNSET
- Will raise an error.
Default: UNSET
do_simple
bool
If True
, use a simplification when calculating relative humidity.
Default: False
do_damping
bool
If True
, the
damping_driver_nml
namelist needs
to be specified.
Default: False
Radiation
two_stream_gray
bool
This is one of three choices for radiation, the others being do_rrtm_radiation
and
do_socrates_radiation
. If True
, the
two_stream_gray_nml
namelist needs
to be specified.
Default: True
do_rrtm_radiation
bool
This is one of three choices for radiation, the others being two_stream_gray
and
do_socrates_radiation
. If True
, the
rrtm_radiation_nml
namelist needs
to be specified.
Default: False
do_socrates_radiation
bool
This is one of three choices for radiation, the others being two_stream_gray
and
do_rrtm_radiation
. If True
, the
socrates_rad_nml
namelist needs
to be specified.
Default: False
Turbulence
These options are all related to how Isca computes surface exchange of heat, momentum and humidity.
turb
bool
If True
, vertical diffusion is enabled and the vert_turb_driver_nml
namelist needs to be specified.
Default: False
do_virtual
bool
If True
, the virtual temperature is used in the
vertical diffusion module.
Default: False
roughness_moist
float
Roughness length for use in surface moisture exchange.
Default: 0.05
roughness_mom
float
Roughness length for use in surface momentum exchange.
Default: 0.05
roughness_heat
float
Roughness length for use in surface heat exchange.
Default: 0.05
Land and Hydrology
Land and hydrology processes are predominantly dealt with in the surface_flux_nml
and
the mixed_layer_nml
namelists, but land and bucket hydrology options are initialised
with the following namelist parameters.
Land is implemented in Isca via adjustment of the roughness length (larger over land), evaporative flux (smaller over land), albedo (larger over land) and mixed layer depth/ heat capacity (smaller over land).
Isca give an example script using land.
The file indicated by land_file_name
is generated using the write_land
function
within isca_tools
.
mixed_layer_bc
bool
If True
, the mixed_layer
module is called and the mixed_layer_nml
namelist needs to be specified.
Default: False
land_option
string There are 3 choices of the land mask in Isca:
input
- Read land mask from input file.zsurf
- Define land where surface geopotential height at model initialisation exceeds a threshold of 10.none
- Do not apply land mask.
This should be set to the same value as land_option
in the
mixed_layer_nml
namelist.
Default: none
land_file_name
string
Filename for the input land-mask.Only ever required if land_option = 'input'
.
If the file is called land.nc
and is in the input_dir
then land_file_name
should be INPUT/land.nc
.
Default: 'INPUT/land.nc'
land_field_name
string
Field name in the input land-mask netcdf.Only ever required if land_option = 'input'
.
Default: land_mask
land_roughness_prefactor
float
Multiplier on the roughness lengths to allow land-ocean contrast.
Expect this to be greater than 1
because land is rougher than ocean.
Only ever required if land_option
is not none
.
Default: 1.0
bucket
bool
If True
, use bucket hydrology.
Isca give an
example script
using bucket hydrology.
Default: False
init_bucket_depth
float
Value at which to initialise bucket water depth over ocean (in \(m\)). Should be large.
Only ever required if bucket = .true.
.
Default: 1000
init_bucket_depth_land
float
Value at which to initialise bucket water depth over land (in \(m\)).
Only ever required if bucket = .true.
.
Default: 20
max_bucket_depth_land
float
Maximum depth of water in bucket over land following initialisation..
Only ever required if bucket = .true.
.
Default: 0.15
robert_bucket
float
Robert coefficient for Roberts-Asselin-Williams filter
on bucket leapfrog timestepping.
Only ever required if bucket = .true.
.
Default: 0.04
raw_bucket
float
RAW coefficient for Roberts-Asselin-Williams filter
on bucket leapfrog timestepping.
Only ever required if bucket = .true.
.
Default: 0.53
Diagnostics
The diagnostics for
this module
can be specified using the module_name
of atmosphere
in the
diagnostic table file. The list of available diagnostics is available on
Isca's website.
Some are also given below:
rh
Relative humidity. Dimensions: time, lat, lon, pressure Units: \(\%\)
precipitation
Rain and Snow from resolved and parameterised condensation/convection. Dimensions: time, lat, lon Units: \(kgm^{-2}s^{-1}\)
Condensation
condensation_rain
Rain from condensation. Dimensions: time, lat, lon Units: \(kgm^{-2}s^{-1}\)
dt_qg_condensation
Moisture tendency from condensation. Dimensions: time, lat, lon, pressure Units: \(kgkg^{-1}s^{-1}\)
dt_tg_condensation
Temperature tendency from condensation. Dimensions: time, lat, lon, pressure Units: \(Ks^{-1}\)
Convection
convection_rain
Convective precipitation. Dimensions: time, lat, lon Units: \(kgm^{-2}s^{-1}\)
dt_qg_convection
Moisture tendency from convection. Dimensions: time, lat, lon, pressure Units: \(kgkg^{-1}s^{-1}\)
dt_tg_convection
Temperature tendency from convection. Dimensions: time, lat, lon, pressure Units: \(Ks^{-1}\)
cape
Convective Available Potential Energy. Dimensions: time, lat, lon Units: \(Jkg^{-1}\)
cin
Convective Inhibition. Dimensions: time, lat, lon Units: \(Jkg^{-1}\)
Near Surface Variables
temp_2m
Air temperature \(2m\) above surface. Dimensions: time, lat, lon Units: \(K\)
sphum_2m
Specific humidity \(2m\) above surface. Dimensions: time, lat, lon Units: \(kg/kg\)
rh_2m
Relative humidity \(2m\) above surface. Dimensions: time, lat, lon Units: \(\%\)
u_10m
Zonal wind \(10m\) above surface. Dimensions: time, lat, lon Units: \(ms^{-1}\)
v_10m
Meridional wind \(10m\) above surface. Dimensions: time, lat, lon Units: \(ms^{-1}\)