! Copyright (c) 2004-2024 Lars Nerger ! ! This file is part of PDAF. ! ! PDAF is free software: you can redistribute it and/or modify ! it under the terms of the GNU Lesser General Public License ! as published by the Free Software Foundation, either version ! 3 of the License, or (at your option) any later version. ! ! PDAF is distributed in the hope that it will be useful, ! but WITHOUT ANY WARRANTY; without even the implied warranty of ! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ! GNU Lesser General Public License for more details. ! ! You should have received a copy of the GNU Lesser General Public ! License along with PDAF. If not, see <http://www.gnu.org/licenses/>. ! !$Id$ !BOP ! ! !ROUTINE: PDAF_assimilate_3dvar --- Interface to PDAF for 3DVAR ! ! !INTERFACE: SUBROUTINE PDAF_assimilate_3dvar(U_collect_state, U_distribute_state, & U_init_dim_obs, U_obs_op, U_init_obs, U_prodRinvA, & U_cvt, U_cvt_adj, U_obs_op_lin, U_obs_op_adj, & U_prepoststep, U_next_observation, outflag) ! !DESCRIPTION: ! Interface routine called from the model at each time ! step during the forecast of each ensemble state. If ! the time of the next analysis step is reached the ! forecast state is transferred to PDAF and the analysis ! is computed by calling PDAF_put_state_3dvar. Subsequently, ! PDAF_get_state is called to initialize the next forecast ! phase. ! ! The code is very generic. Basically the only ! filter-specific part are the calls to the ! routines PDAF\_put\_state\_X where the analysis ! is computed and PDAF\_get\_state to initialize the next ! forecast phase. The filter-specific call-back subroutines ! are specified in the calls to the two core routines. ! ! Variant for 3DVAR with domain decomposition. ! ! ! This is a core routine of PDAF and ! should not be changed by the user ! ! ! !REVISION HISTORY: ! 2013-08 - Lars Nerger - Initial code ! Later revisions - see svn log ! ! !USES: USE PDAF_mod_filter, & ONLY: cnt_steps, nsteps, assim_flag, use_PDAF_assim USE PDAF_mod_filtermpi, & ONLY: mype_world IMPLICIT NONE ! !ARGUMENTS: INTEGER, INTENT(out) :: outflag ! Status flag ! ! External subroutines ! ! (PDAF-internal names, real names are defined in the call to PDAF) EXTERNAL :: U_collect_state, & ! Routine to collect a state vector U_init_dim_obs, & ! Initialize dimension of observation vector U_obs_op, & ! Observation operator U_init_obs, & ! Initialize observation vector U_prepoststep, & ! User supplied pre/poststep routine U_prodRinvA, & ! Provide product R^-1 A U_next_observation, & ! Routine to provide time step, time and dimension ! of next observation U_distribute_state, & ! Routine to distribute a state vector U_cvt, & ! Apply control vector transform matrix to control vector U_cvt_adj, & ! Apply adjoint control vector transform matrix U_obs_op_lin, & ! Linearized observation operator U_obs_op_adj ! Adjoint observation operator ! !CALLING SEQUENCE: ! Called by: model code ! Calls: PDAF_put_state_3dvar ! Calls: PDAF_get_state !EOP ! Local variables INTEGER :: steps ! Number of time steps in next forecast phase INTEGER :: doexit ! Exit flag; not used in this variant REAL :: time ! Current model time; not used in this variant ! ***************************** ! *** At each time step *** ! ***************************** ! Set flag for using PDAF_assimilate use_PDAF_assim = .TRUE. ! Increment time step counter cnt_steps = cnt_steps + 1 ! ******************************** ! *** At end of forecast phase *** ! ******************************** IF (cnt_steps == nsteps) THEN IF (mype_world==0) WRITE(*,'(a, 5x, a)') 'PDAF', 'Perform assimilation with PDAF' ! Set flag for assimilation assim_flag = 1 ! *** Call analysis step *** CALL PDAF_put_state_3dvar(U_collect_state, & U_init_dim_obs, U_obs_op, U_init_obs, U_prodRinvA, & U_cvt, U_cvt_adj, U_obs_op_lin, U_obs_op_adj, & U_prepoststep, outflag) ! *** Prepare start of next ensemble forecast *** IF (outflag==0) THEN CALL PDAF_get_state(steps, time, doexit, U_next_observation, U_distribute_state, & U_prepoststep, outflag) END IF nsteps = steps ELSE assim_flag = 0 outflag = 0 END IF END SUBROUTINE PDAF_assimilate_3dvar