Version 2 (modified by 4 weeks ago) (diff) | ,
---|
PDAFomi_assimilate_3dvar
This page documents the routine PDAFomi_assimilate_3dvar
of PDAF.
The routine is typically called in assimilate_pdaf
or directly in the model code.
The general aspects of the filter specific routines PDAF_assimilate_*
are described on the page Modification of the model code for the ensemble integration and its sub-page on inserting the analysis step. The routine is used in the fully-parallel implementation variant of the data assimilation system. When the 'flexible' implementation variant, the routines `PDAF_put_state_*' are used.
The interface for using the parameterized 3D-Var is:
SUBROUTINE PDAFomi_assimilate_3dvar(U_collect_state, U_distribute_state, & U_init_dim_obs_pdafomi, U_obs_op_pdafomi, & U_cvt, U_cvt_adj, U_obs_op_lin_pdafomi, obs_op_adj_pdafomi, & U_prepoststep, U_next_observation, outflag)
with the following arguments:
- U_collect_state: The name of the user-supplied routine that initializes a state vector from the array holding the ensemble of model states from the model fields. This is basically the inverse operation to
U_distribute_state
used inPDAF_get_state
as well as here. - U_distribute_state: The name of a user supplied routine that initializes the model fields from the array holding the ensemble of model state vectors.
- U_init_dim_obs_pdafomi: The name of the user-supplied routine that initializes the observation information and provides the size of observation vector
- U_cvt: The name of the user-supplied routine that applies the control-vector transformation (square-root of the B-matrix) on some control vector to obtain a state vector.
- U_cvt_adj: The name of the user-supplied routine that applies the adjoint control-vector transformation (with square-root of the B-matrix) on some state vector to obtain the control vector.
- U_obs_op_pdafomi: The name of the user-supplied routine that acts as the observation operator on some state vector
- U_obs_op_lin_pdafomi: The name of the user-supplied routine that acts as the linearized observation operator on some state vector
- U_obs_op_lin_pdafomi: The name of the user-supplied routine that acts as the adjoint observation operator on some state vector
- U_prepoststep: The name of the pre/poststep routine as in
PDAF_get_state
- U_next_observation: The name of a user supplied routine that initializes the variables
nsteps
,timenow
, anddoexit
. The same routine is also used inPDAF_get_state
. status
: The integer status flag. It is zero, ifPDAFomi_assimilate_3dvar
is exited without errors.
The user-supplied call-back routines are described on the page on [ImplementAnalysis_3DVar implementing the analysis step of 3D-Var with OMI].
It is recommended that the value of status_pdaf
is checked in the program after the routine is executed. Only if its value is 0 the initialization was successful.