SQG¶
Overview¶
This is a uniform PV two-surface QG+1 spectral model contributed by Rahul Majahan.
The underlying model is described in: Hakim, Gregory J., 2000: Role of Nonmodal Growth and Nonlinearity in Cyclogenesis Initial-Value Problems. J. Atmos. Sci., 57, 2951-2967. doi: 10.1175/1520-0469(2000)057<2951:RONGAN>2.0.CO;2
Other modules used¶
types_mod
time_manager_mod
threed_sphere/location_mod
utilities_mod
Public interfaces¶
use model_mod, only : |
get_model_size |
adv_1step |
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get_state_meta_data |
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model_interpolate |
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get_model_time_step |
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static_init_model |
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end_model |
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init_time |
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init_conditions |
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nc_write_model_atts |
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nc_write_model_vars |
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pert_model_state |
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get_close_maxdist_init |
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get_close_obs_init |
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get_close_obs |
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ens_mean_for_model |
Optional namelist interface &model_nml may be read from file input.nml.
A note about documentation style. Optional arguments are enclosed in brackets [like this].
model_size = get_model_size( )
integer :: get_model_size
Returns the length of the model state vector.
|
The length of the model state vector. |
call adv_1step(x, time)
real(r8), dimension(:), intent(inout) :: x
type(time_type), intent(in) :: time
Advances the model for a single time step. The time associated with the initial model state is also input although it is not used for the computation.
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State vector of length model_size. |
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Specifies time of the initial model state. |
call get_state_meta_data (index_in, location, [, var_type] )
integer, intent(in) :: index_in
type(location_type), intent(out) :: location
integer, optional, intent(out) :: var_type
Returns metadata about a given element, indexed by index_in, in the model state vector. The location defines where the state variable is located.
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Index of state vector element about which information is requested. |
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The location of state variable element. |
var_type |
Returns the type (always 1) of the indexed state variable as an optional argument. |
call model_interpolate(x, location, itype, obs_val, istatus)
real(r8), dimension(:), intent(in) :: x
type(location_type), intent(in) :: location
integer, intent(in) :: itype
real(r8), intent(out) :: obs_val
integer, intent(out) :: istatus
Given model state, returns the value interpolated to a given location.
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A model state vector. |
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Location to which to interpolate. |
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Not used. |
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The interpolated value from the model. |
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Quality control information, always returned 0. |
var = get_model_time_step()
type(time_type) :: get_model_time_step
Returns the time step (forecast length) of the model;
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Smallest time step of model. |
call static_init_model()
Used for runtime initialization of model; reads namelist, initializes model parameters, etc. This is the first call made to the model by any DART-compliant assimilation routine.
call end_model()
A stub.
call init_time(time)
type(time_type), intent(out) :: time
Returns the time at which the model will start if no input initial conditions are to be used. This is used to spin-up the model from rest.
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Initial model time. |
call init_conditions(x)
real(r8), dimension(:), intent(out) :: x
Returns default initial conditions for the model; generally used for spinning up initial model states.
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Initial conditions for state vector. |
ierr = nc_write_model_atts(ncFileID)
integer :: nc_write_model_atts
integer, intent(in) :: ncFileID
Function to write model specific attributes to a netCDF file. At present, DART is using the NetCDF format to output diagnostic information. This is not a requirement, and models could choose to provide output in other formats. This function writes the metadata associated with the model to a NetCDF file opened to a file identified by ncFileID.
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Integer file descriptor to previously-opened netCDF file. |
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Returns a 0 for successful completion. |
ierr = nc_write_model_vars(ncFileID, statevec, copyindex, timeindex)
integer :: nc_write_model_vars
integer, intent(in) :: ncFileID
real(r8), dimension(:), intent(in) :: statevec
integer, intent(in) :: copyindex
integer, intent(in) :: timeindex
Writes a copy of the state variables to a netCDF file. Multiple copies of the state for a given time are supported, allowing, for instance, a single file to include multiple ensemble estimates of the state.
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file descriptor to previously-opened netCDF file. |
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A model state vector. |
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Integer index of copy to be written. |
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The timestep counter for the given state. |
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Returns 0 for normal completion. |
call pert_model_state(state, pert_state, interf_provided)
real(r8), dimension(:), intent(in) :: state
real(r8), dimension(:), intent(out) :: pert_state
logical, intent(out) :: interf_provided
Given a model state, produces a perturbed model state.
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State vector to be perturbed. |
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Perturbed state vector: NOT returned. |
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Returned false; interface is not implemented. |
call get_close_maxdist_init(gc, maxdist)
type(get_close_type), intent(inout) :: gc
real(r8), intent(in) :: maxdist
Pass-through to the 3D Sphere locations module. See get_close_maxdist_init() for the documentation of this subroutine.
call get_close_obs_init(gc, num, obs)
type(get_close_type), intent(inout) :: gc
integer, intent(in) :: num
type(location_type), intent(in) :: obs(num)
Pass-through to the 3D Sphere locations module. See get_close_obs_init() for the documentation of this subroutine.
call get_close_obs(gc, base_obs_loc, base_obs_kind, obs, obs_kind, num_close, close_ind [, dist])
type(get_close_type), intent(in) :: gc
type(location_type), intent(in) :: base_obs_loc
integer, intent(in) :: base_obs_kind
type(location_type), intent(in) :: obs(:)
integer, intent(in) :: obs_kind(:)
integer, intent(out) :: num_close
integer, intent(out) :: close_ind(:)
real(r8), optional, intent(out) :: dist(:)
Pass-through to the 3D Sphere locations module. See get_close_obs() for the documentation of this subroutine.
call ens_mean_for_model(ens_mean)
real(r8), dimension(:), intent(in) :: ens_mean
A NULL INTERFACE in this model.
|
State vector containing the ensemble mean. |
Namelist¶
We adhere to the F90 standard of starting a namelist with an ampersand ‘&’ and terminating with a slash ‘/’ for all our namelist input.
&model_nml
output_state_vector = .false.
channel_center = 45.0
channel_width = 40.0
assimilation_period_days = 0
assimilation_period_seconds = 21600
debug = .false.
/
This namelist is read in a file called input.nml
Contents |
Type |
Description |
|---|---|---|
output_state_vector |
logical |
If .true. write state vector as a 1D array to the diagnostic output file. If .false. break state vector up into fields before writing to the outputfile. |
channel_center |
real(r8) |
Channel center |
channel_width |
real(r8) |
Channel width |
assimilation_period_days |
integer |
Number of days for timestep |
assimilation_period_seconds |
integer |
Number of seconds for timestep |
debug |
logical |
Set to .true. for more output |
Files¶
filename |
purpose |
|---|---|
input.nml |
to read the model_mod namelist |
preassim.nc |
the time-history of the model state before assimilation |
analysis.nc |
the time-history of the model state after assimilation |
dart_log.out [default name] |
the run-time diagnostic output |
dart_log.nml [default name] |
the record of all the namelists actually USED - contains the default values |
References¶
Private components¶
N/A