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asminc.F90 in branches/2017/dev_merge_2017/NEMOGCM/NEMO/OPA_SRC/ASM – NEMO

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source: branches/2017/dev_merge_2017/NEMOGCM/NEMO/OPA_SRC/ASM/asminc.F90 @ 9213

Last change on this file since 9213 was 9213, checked in by gm, 6 years ago
dev_merge_2017: nemogcm.F90 : updated in SAS & OFF + data assimilation initial calls (asm_bkg_wri , tra_asm_inc ...) moved to asm_inc_init + closed sea : restructure namcfg & its control print + set ln_closea = false if domcfg file not read (ln_domcfg=F
Property svn:keywords set to `Id`
File size: 47.7 KB

Rev	Line
[2128]	1	MODULE asminc
	2	!!======================================================================
	3	!! * MODULE asminc *
	4	!! Assimilation increment : Apply an increment generated by data
	5	!! assimilation
	6	!!======================================================================
[2392]	7	!! History : ! 2007-03 (M. Martin) Met Office version
	8	!! ! 2007-04 (A. Weaver) calc_date original code
	9	!! ! 2007-04 (A. Weaver) Merge with OPAVAR/NEMOVAR
	10	!! NEMO 3.3 ! 2010-05 (D. Lea) Update to work with NEMO v3.2
	11	!! - ! 2010-05 (D. Lea) add calc_month_len routine based on day_init
[3764]	12	!! 3.4 ! 2012-10 (A. Weaver and K. Mogensen) Fix for direct initialization
[6140]	13	!! ! 2014-09 (D. Lea) Local calc_date removed use routine from OBS
	14	!! ! 2015-11 (D. Lea) Handle non-zero initial time of day
[2392]	15	!!----------------------------------------------------------------------
[2128]	16
	17	!!----------------------------------------------------------------------
[3785]	18	!! asm_inc_init : Initialize the increment arrays and IAU weights
	19	!! tra_asm_inc : Apply the tracer (T and S) increments
	20	!! dyn_asm_inc : Apply the dynamic (u and v) increments
	21	!! ssh_asm_inc : Apply the SSH increment
[9023]	22	!! ssh_asm_div : Apply divergence associated with SSH increment
[3785]	23	!! seaice_asm_inc : Apply the seaice increment
[2128]	24	!!----------------------------------------------------------------------
[9019]	25	USE oce ! Dynamics and active tracers defined in memory
	26	USE par_oce ! Ocean space and time domain variables
	27	USE dom_oce ! Ocean space and time domain
	28	USE domvvl ! domain: variable volume level
	29	USE ldfdyn ! lateral diffusion: eddy viscosity coefficients
	30	USE eosbn2 ! Equation of state - in situ and potential density
	31	USE zpshde ! Partial step : Horizontal Derivative
	32	USE asmpar ! Parameters for the assmilation interface
	33	USE c1d ! 1D initialization
	34	USE sbc_oce ! Surface boundary condition variables.
	35	USE diaobs , ONLY : calc_date ! Compute the calendar date on a given step
	36	#if defined key_lim3
	37	USE ice , ONLY : hm_i, at_i, at_i_b
[3764]	38	#endif
[9019]	39	!
	40	USE in_out_manager ! I/O manager
	41	USE iom ! Library to read input files
	42	USE lib_mpp ! MPP library
[2128]	43
	44	IMPLICIT NONE
	45	PRIVATE
[2392]	46
	47	PUBLIC asm_inc_init !: Initialize the increment arrays and IAU weights
	48	PUBLIC tra_asm_inc !: Apply the tracer (T and S) increments
	49	PUBLIC dyn_asm_inc !: Apply the dynamic (u and v) increments
	50	PUBLIC ssh_asm_inc !: Apply the SSH increment
[9023]	51	PUBLIC ssh_asm_div !: Apply the SSH divergence
[3764]	52	PUBLIC seaice_asm_inc !: Apply the seaice increment
[2128]	53
	54	#if defined key_asminc
[2392]	55	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
[2128]	56	#else
[2392]	57	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
[2128]	58	#endif
[5836]	59	LOGICAL, PUBLIC :: ln_bkgwri !: No output of the background state fields
	60	LOGICAL, PUBLIC :: ln_asmiau !: No applying forcing with an assimilation increment
	61	LOGICAL, PUBLIC :: ln_asmdin !: No direct initialization
	62	LOGICAL, PUBLIC :: ln_trainc !: No tracer (T and S) assimilation increments
	63	LOGICAL, PUBLIC :: ln_dyninc !: No dynamics (u and v) assimilation increments
	64	LOGICAL, PUBLIC :: ln_sshinc !: No sea surface height assimilation increment
	65	LOGICAL, PUBLIC :: ln_seaiceinc !: No sea ice concentration increment
	66	LOGICAL, PUBLIC :: ln_salfix !: Apply minimum salinity check
[3764]	67	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
[5836]	68	INTEGER, PUBLIC :: nn_divdmp !: Apply divergence damping filter nn_divdmp times
[2128]	69
[2392]	70	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkg , s_bkg !: Background temperature and salinity
	71	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkg , v_bkg !: Background u- & v- velocity components
	72	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkginc, s_bkginc !: Increment to the background T & S
	73	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkginc, v_bkginc !: Increment to the u- & v-components
	74	REAL(wp), PUBLIC, DIMENSION(:) , ALLOCATABLE :: wgtiau !: IAU weights for each time step
[2128]	75	#if defined key_asminc
[9213]	76	REAL(wp), PUBLIC, DIMENSION(:,:) , ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
[2128]	77	#endif
[2392]	78	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
	79	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
	80	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
	81	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
	82	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
	83	!
	84	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
	85	! !: = 1 Linear hat-like, centred in middle of IAU interval
	86	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
[2128]	87
[2392]	88	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
[3764]	89	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
[8030]	90	#if defined key_cice && defined key_asminc
	91	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ndaice_da ! ice increment tendency into CICE
	92	#endif
[2128]	93
[3294]	94	!! * Substitutions
	95	# include "vectopt_loop_substitute.h90"
[2287]	96	!!----------------------------------------------------------------------
[6140]	97	!! NEMO/OPA 3.7 , NEMO Consortium (2015)
[2287]	98	!! $Id$
[2392]	99	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
[2287]	100	!!----------------------------------------------------------------------
[2128]	101	CONTAINS
	102
	103	SUBROUTINE asm_inc_init
	104	!!----------------------------------------------------------------------
	105	!! * ROUTINE asm_inc_init *
	106	!!
	107	!! ** Purpose : Initialize the assimilation increment and IAU weights.
	108	!!
	109	!! ** Method : Initialize the assimilation increment and IAU weights.
	110	!!
	111	!! ** Action :
	112	!!----------------------------------------------------------------------
[4990]	113	INTEGER :: ji, jj, jk, jt ! dummy loop indices
	114	INTEGER :: imid, inum ! local integers
	115	INTEGER :: ios ! Local integer output status for namelist read
[2128]	116	INTEGER :: iiauper ! Number of time steps in the IAU period
	117	INTEGER :: icycper ! Number of time steps in the cycle
[6140]	118	REAL(KIND=dp) :: ditend_date ! Date YYYYMMDD.HHMMSS of final time step
	119	REAL(KIND=dp) :: ditbkg_date ! Date YYYYMMDD.HHMMSS of background time step for Jb term
	120	REAL(KIND=dp) :: ditdin_date ! Date YYYYMMDD.HHMMSS of background time step for DI
	121	REAL(KIND=dp) :: ditiaustr_date ! Date YYYYMMDD.HHMMSS of IAU interval start time step
	122	REAL(KIND=dp) :: ditiaufin_date ! Date YYYYMMDD.HHMMSS of IAU interval final time step
	123
[2128]	124	REAL(wp) :: znorm ! Normalization factor for IAU weights
[4990]	125	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights (should be equal to one)
[2128]	126	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
	127	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
	128	REAL(wp) :: zdate_bkg ! Date in background state file for DI
	129	REAL(wp) :: zdate_inc ! Time axis in increments file
[4990]	130	!
[9019]	131	REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: zhdiv ! 2D workspace
[2392]	132	!!
[3764]	133	NAMELIST/nam_asminc/ ln_bkgwri, &
[2392]	134	& ln_trainc, ln_dyninc, ln_sshinc, &
	135	& ln_asmdin, ln_asmiau, &
	136	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
[4990]	137	& ln_salfix, salfixmin, nn_divdmp
[2392]	138	!!----------------------------------------------------------------------
[2128]	139
	140	!-----------------------------------------------------------------------
	141	! Read Namelist nam_asminc : assimilation increment interface
	142	!-----------------------------------------------------------------------
[5836]	143	ln_seaiceinc = .FALSE.
[3764]	144	ln_temnofreeze = .FALSE.
[2128]	145
[4147]	146	REWIND( numnam_ref ) ! Namelist nam_asminc in reference namelist : Assimilation increment
	147	READ ( numnam_ref, nam_asminc, IOSTAT = ios, ERR = 901)
[9168]	148	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in reference namelist', lwp )
[4147]	149	REWIND( numnam_cfg ) ! Namelist nam_asminc in configuration namelist : Assimilation increment
	150	READ ( numnam_cfg, nam_asminc, IOSTAT = ios, ERR = 902 )
[9168]	151	902 IF( ios > 0 ) CALL ctl_nam ( ios , 'nam_asminc in configuration namelist', lwp )
[4624]	152	IF(lwm) WRITE ( numond, nam_asminc )
[4147]	153
[2128]	154	! Control print
	155	IF(lwp) THEN
	156	WRITE(numout,*)
	157	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
	158	WRITE(numout,*) '~~~~~~~~~~~~'
[2392]	159	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
	160	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
	161	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
	162	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
	163	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
	164	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
[3764]	165	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
[2392]	166	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
	167	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
	168	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
	169	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
	170	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
	171	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
	172	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
	173	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
[2128]	174	ENDIF
	175
[9019]	176	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
	177	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
	178	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
	179	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
[2128]	180
[9019]	181	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
	182	icycper = nitend - nit000 + 1 ! Cycle interval length
[2128]	183
[9019]	184	CALL calc_date( nitend , ditend_date ) ! Date of final time step
	185	CALL calc_date( nitbkg_r , ditbkg_date ) ! Background time for Jb referenced to ndate0
	186	CALL calc_date( nitdin_r , ditdin_date ) ! Background time for DI referenced to ndate0
	187	CALL calc_date( nitiaustr_r, ditiaustr_date ) ! IAU start time referenced to ndate0
	188	CALL calc_date( nitiaufin_r, ditiaufin_date ) ! IAU end time referenced to ndate0
[6140]	189
[2128]	190	IF(lwp) THEN
	191	WRITE(numout,*)
	192	WRITE(numout,*) ' Time steps referenced to current cycle:'
	193	WRITE(numout,*) ' iitrst = ', nit000 - 1
	194	WRITE(numout,*) ' nit000 = ', nit000
	195	WRITE(numout,*) ' nitend = ', nitend
	196	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
	197	WRITE(numout,*) ' nitdin_r = ', nitdin_r
	198	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
	199	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
	200	WRITE(numout,*)
	201	WRITE(numout,*) ' Dates referenced to current cycle:'
	202	WRITE(numout,*) ' ndastp = ', ndastp
	203	WRITE(numout,*) ' ndate0 = ', ndate0
[6140]	204	WRITE(numout,*) ' nn_time0 = ', nn_time0
	205	WRITE(numout,*) ' ditend_date = ', ditend_date
	206	WRITE(numout,*) ' ditbkg_date = ', ditbkg_date
	207	WRITE(numout,*) ' ditdin_date = ', ditdin_date
	208	WRITE(numout,*) ' ditiaustr_date = ', ditiaustr_date
	209	WRITE(numout,*) ' ditiaufin_date = ', ditiaufin_date
[2128]	210	ENDIF
	211
	212
	213	IF ( ( ln_asmdin ).AND.( ln_asmiau ) ) &
	214	& CALL ctl_stop( ' ln_asmdin and ln_asmiau :', &
	215	& ' Choose Direct Initialization OR Incremental Analysis Updating')
	216
	217	IF ( ( ( .NOT. ln_asmdin ).AND.( .NOT. ln_asmiau ) ) &
[3764]	218	.AND.( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ) .OR. ( ln_seaiceinc) )) &
	219	& CALL ctl_stop( ' One or more of ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc is set to .true.', &
[2128]	220	& ' but ln_asmdin and ln_asmiau are both set to .false. :', &
	221	& ' Inconsistent options')
	222
	223	IF ( ( niaufn /= 0 ).AND.( niaufn /= 1 ) ) &
	224	& CALL ctl_stop( ' niaufn /= 0 or niaufn /=1 :', &
	225	& ' Type IAU weighting function is invalid')
	226
[3764]	227	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ).AND.( .NOT. ln_seaiceinc ) &
[2128]	228	& ) &
[3764]	229	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc are set to .false. :', &
[2128]	230	& ' The assimilation increments are not applied')
	231
	232	IF ( ( ln_asmiau ).AND.( nitiaustr == nitiaufin ) ) &
	233	& CALL ctl_stop( ' nitiaustr = nitiaufin :', &
	234	& ' IAU interval is of zero length')
	235
	236	IF ( ( ln_asmiau ).AND.( ( nitiaustr_r < nit000 ).OR.( nitiaufin_r > nitend ) ) ) &
	237	& CALL ctl_stop( ' nitiaustr or nitiaufin :', &
	238	& ' IAU starting or final time step is outside the cycle interval', &
	239	& ' Valid range nit000 to nitend')
	240
	241	IF ( ( nitbkg_r < nit000 - 1 ).OR.( nitbkg_r > nitend ) ) &
	242	& CALL ctl_stop( ' nitbkg :', &
	243	& ' Background time step is outside the cycle interval')
	244
	245	IF ( ( nitdin_r < nit000 - 1 ).OR.( nitdin_r > nitend ) ) &
	246	& CALL ctl_stop( ' nitdin :', &
	247	& ' Background time step for Direct Initialization is outside', &
	248	& ' the cycle interval')
	249
	250	IF ( nstop > 0 ) RETURN ! if there are any errors then go no further
	251
	252	!--------------------------------------------------------------------
	253	! Initialize the Incremental Analysis Updating weighting function
	254	!--------------------------------------------------------------------
	255
[9213]	256	IF( ln_asmiau ) THEN
	257	!
[2128]	258	ALLOCATE( wgtiau( icycper ) )
[9213]	259	!
[9019]	260	wgtiau(:) = 0._wp
[9213]	261	!
	262	! !---------------------------------------------------------
	263	IF( niaufn == 0 ) THEN ! Constant IAU forcing
	264	! !---------------------------------------------------------
[2128]	265	DO jt = 1, iiauper
	266	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
	267	END DO
[9213]	268	! !---------------------------------------------------------
	269	ELSEIF ( niaufn == 1 ) THEN ! Linear hat-like, centred in middle of IAU interval
	270	! !---------------------------------------------------------
[2128]	271	! Compute the normalization factor
[9213]	272	znorm = 0._wp
	273	IF( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
[2128]	274	imid = iiauper / 2
	275	DO jt = 1, imid
	276	znorm = znorm + REAL( jt )
	277	END DO
	278	znorm = 2.0 * znorm
[9213]	279	ELSE ! Odd number of time steps in IAU interval
[2128]	280	imid = ( iiauper + 1 ) / 2
	281	DO jt = 1, imid - 1
	282	znorm = znorm + REAL( jt )
	283	END DO
	284	znorm = 2.0 * znorm + REAL( imid )
	285	ENDIF
	286	znorm = 1.0 / znorm
[9213]	287	!
[2128]	288	DO jt = 1, imid - 1
	289	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
	290	END DO
	291	DO jt = imid, iiauper
	292	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
	293	END DO
[9213]	294	!
[2128]	295	ENDIF
	296
	297	! Test that the integral of the weights over the weighting interval equals 1
	298	IF(lwp) THEN
	299	WRITE(numout,*)
	300	WRITE(numout,*) 'asm_inc_init : IAU weights'
	301	WRITE(numout,*) '~~~~~~~~~~~~'
	302	WRITE(numout,*) ' time step IAU weight'
	303	WRITE(numout,*) ' ========= ====================='
	304	ztotwgt = 0.0
	305	DO jt = 1, icycper
	306	ztotwgt = ztotwgt + wgtiau(jt)
	307	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
	308	END DO
	309	WRITE(numout,*) ' ==================================='
	310	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
	311	WRITE(numout,*) ' ==================================='
	312	ENDIF
	313
	314	ENDIF
	315
	316	!--------------------------------------------------------------------
	317	! Allocate and initialize the increment arrays
	318	!--------------------------------------------------------------------
	319
[9213]	320	ALLOCATE( t_bkginc (jpi,jpj,jpk) ) ; t_bkginc (:,:,:) = 0._wp
	321	ALLOCATE( s_bkginc (jpi,jpj,jpk) ) ; s_bkginc (:,:,:) = 0._wp
	322	ALLOCATE( u_bkginc (jpi,jpj,jpk) ) ; u_bkginc (:,:,:) = 0._wp
	323	ALLOCATE( v_bkginc (jpi,jpj,jpk) ) ; v_bkginc (:,:,:) = 0._wp
	324	ALLOCATE( ssh_bkginc (jpi,jpj) ) ; ssh_bkginc (:,:) = 0._wp
	325	ALLOCATE( seaice_bkginc(jpi,jpj) ) ; seaice_bkginc(:,:) = 0._wp
[2128]	326	#if defined key_asminc
[9213]	327	ALLOCATE( ssh_iau (jpi,jpj) ) ; ssh_iau (:,:) = 0._wp
[2128]	328	#endif
[8030]	329	#if defined key_cice && defined key_asminc
[9213]	330	ALLOCATE( ndaice_da (jpi,jpj) ) ; ndaice_da (:,:) = 0._wp
[8030]	331	#endif
[9213]	332	!
	333	IF ( ln_trainc .OR. ln_dyninc .OR. & !--------------------------------------
	334	& ln_sshinc .OR. ln_seaiceinc ) THEN ! Read the increments from file
	335	! !--------------------------------------
[2128]	336	CALL iom_open( c_asminc, inum )
[9213]	337	!
	338	CALL iom_get( inum, 'time' , zdate_inc )
[2128]	339	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
	340	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
	341	z_inc_dateb = zdate_inc
	342	z_inc_datef = zdate_inc
[9213]	343	!
[2128]	344	IF(lwp) THEN
	345	WRITE(numout,*)
[9213]	346	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid between dates ', z_inc_dateb,' and ', z_inc_datef
[2128]	347	WRITE(numout,*) '~~~~~~~~~~~~'
	348	ENDIF
[9213]	349	!
	350	IF ( ( z_inc_dateb < ndastp + nn_time0*0.0001_wp ) .OR. &
	351	& ( z_inc_datef > ditend_date ) ) &
	352	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
	353	& ' outside the assimilation interval' )
[2128]	354
[6140]	355	IF ( ( ln_asmdin ).AND.( zdate_inc /= ditdin_date ) ) &
[2128]	356	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
	357	& ' not agree with Direct Initialization time' )
	358
	359	IF ( ln_trainc ) THEN
	360	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
	361	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
	362	! Apply the masks
	363	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
	364	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
	365	! Set missing increments to 0.0 rather than 1e+20
	366	! to allow for differences in masks
	367	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
	368	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
	369	ENDIF
	370
	371	IF ( ln_dyninc ) THEN
	372	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
	373	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
	374	! Apply the masks
	375	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
	376	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
	377	! Set missing increments to 0.0 rather than 1e+20
	378	! to allow for differences in masks
	379	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
	380	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
	381	ENDIF
	382
	383	IF ( ln_sshinc ) THEN
	384	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
	385	! Apply the masks
	386	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
	387	! Set missing increments to 0.0 rather than 1e+20
	388	! to allow for differences in masks
	389	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
	390	ENDIF
	391
[3764]	392	IF ( ln_seaiceinc ) THEN
	393	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
	394	! Apply the masks
	395	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
	396	! Set missing increments to 0.0 rather than 1e+20
	397	! to allow for differences in masks
	398	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
	399	ENDIF
[9213]	400	!
[2128]	401	CALL iom_close( inum )
[9213]	402	!
[2128]	403	ENDIF
[9213]	404	!
	405	! !--------------------------------------
	406	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN ! Apply divergence damping filter
	407	! !--------------------------------------
[9019]	408	ALLOCATE( zhdiv(jpi,jpj) )
[5836]	409	!
	410	DO jt = 1, nn_divdmp
	411	!
[9019]	412	DO jk = 1, jpkm1 ! zhdiv = e1e1 * div
	413	zhdiv(:,:) = 0._wp
[3764]	414	DO jj = 2, jpjm1
	415	DO ji = fs_2, fs_jpim1 ! vector opt.
[9019]	416	zhdiv(ji,jj) = ( e2u(ji ,jj) * e3u_n(ji ,jj,jk) * u_bkginc(ji ,jj,jk) &
	417	& - e2u(ji-1,jj) * e3u_n(ji-1,jj,jk) * u_bkginc(ji-1,jj,jk) &
	418	& + e1v(ji,jj ) * e3v_n(ji,jj ,jk) * v_bkginc(ji,jj ,jk) &
	419	& - e1v(ji,jj-1) * e3v_n(ji,jj-1,jk) * v_bkginc(ji,jj-1,jk) ) / e3t_n(ji,jj,jk)
[3764]	420	END DO
[3294]	421	END DO
[9019]	422	CALL lbc_lnk( zhdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
[5836]	423	!
[3764]	424	DO jj = 2, jpjm1
	425	DO ji = fs_2, fs_jpim1 ! vector opt.
[6140]	426	u_bkginc(ji,jj,jk) = u_bkginc(ji,jj,jk) &
[9019]	427	& + 0.2_wp * ( zhdiv(ji+1,jj) - zhdiv(ji ,jj) ) * r1_e1u(ji,jj) * umask(ji,jj,jk)
[6140]	428	v_bkginc(ji,jj,jk) = v_bkginc(ji,jj,jk) &
[9019]	429	& + 0.2_wp * ( zhdiv(ji,jj+1) - zhdiv(ji,jj ) ) * r1_e2v(ji,jj) * vmask(ji,jj,jk)
[3764]	430	END DO
[3294]	431	END DO
	432	END DO
[5836]	433	!
[3764]	434	END DO
[5836]	435	!
[9019]	436	DEALLOCATE( zhdiv )
[5836]	437	!
[3294]	438	ENDIF
[9213]	439	!
	440	! !-----------------------------------------------------
	441	IF ( ln_asmdin ) THEN ! Allocate and initialize the background state arrays
	442	! !-----------------------------------------------------
[5836]	443	!
[9213]	444	ALLOCATE( t_bkg (jpi,jpj,jpk) ) ; t_bkg (:,:,:) = 0._wp
	445	ALLOCATE( s_bkg (jpi,jpj,jpk) ) ; s_bkg (:,:,:) = 0._wp
	446	ALLOCATE( u_bkg (jpi,jpj,jpk) ) ; u_bkg (:,:,:) = 0._wp
	447	ALLOCATE( v_bkg (jpi,jpj,jpk) ) ; v_bkg (:,:,:) = 0._wp
	448	ALLOCATE( ssh_bkg(jpi,jpj) ) ; ssh_bkg(:,:) = 0._wp
[5836]	449	!
	450	!
[2128]	451	!--------------------------------------------------------------------
	452	! Read from file the background state at analysis time
	453	!--------------------------------------------------------------------
[5836]	454	!
[2128]	455	CALL iom_open( c_asmdin, inum )
[5836]	456	!
[3764]	457	CALL iom_get( inum, 'rdastp', zdate_bkg )
[5836]	458	!
[2128]	459	IF(lwp) THEN
	460	WRITE(numout,*)
[9213]	461	WRITE(numout,*) ' ==>>> Assimilation background state valid at : ', zdate_bkg
	462	WRITE(numout,*)
[2128]	463	ENDIF
[5836]	464	!
[9213]	465	IF ( zdate_bkg /= ditdin_date ) &
[2128]	466	& CALL ctl_warn( ' Validity time of assimilation background state does', &
	467	& ' not agree with Direct Initialization time' )
[5836]	468	!
[2128]	469	IF ( ln_trainc ) THEN
	470	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
	471	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
	472	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
	473	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
	474	ENDIF
[5836]	475	!
[2128]	476	IF ( ln_dyninc ) THEN
	477	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
	478	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
	479	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
	480	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
	481	ENDIF
[5836]	482	!
[2128]	483	IF ( ln_sshinc ) THEN
	484	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
	485	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
	486	ENDIF
[5836]	487	!
[2128]	488	CALL iom_close( inum )
[5836]	489	!
[2128]	490	ENDIF
[2392]	491	!
[9213]	492	IF(lwp) WRITE(numout,*) ' ==>>> Euler time step switch is ', neuler
	493	!
	494	IF( lk_asminc ) THEN !== data assimilation ==!
	495	IF( ln_bkgwri ) CALL asm_bkg_wri( nit000 - 1 ) ! Output background fields
	496	IF( ln_asmdin ) THEN ! Direct initialization
	497	IF( ln_trainc ) CALL tra_asm_inc( nit000 - 1 ) ! Tracers
	498	IF( ln_dyninc ) CALL dyn_asm_inc( nit000 - 1 ) ! Dynamics
	499	IF( ln_sshinc ) CALL ssh_asm_inc( nit000 - 1 ) ! SSH
	500	ENDIF
	501	ENDIF
	502	!
[2128]	503	END SUBROUTINE asm_inc_init
[9213]	504
	505
[2128]	506	SUBROUTINE tra_asm_inc( kt )
	507	!!----------------------------------------------------------------------
	508	!! * ROUTINE tra_asm_inc *
	509	!!
	510	!! ** Purpose : Apply the tracer (T and S) assimilation increments
	511	!!
	512	!! ** Method : Direct initialization or Incremental Analysis Updating
	513	!!
	514	!! ** Action :
	515	!!----------------------------------------------------------------------
[5836]	516	INTEGER, INTENT(IN) :: kt ! Current time step
[2392]	517	!
[5836]	518	INTEGER :: ji, jj, jk
	519	INTEGER :: it
[2128]	520	REAL(wp) :: zincwgt ! IAU weight for current time step
[3764]	521	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
[2392]	522	!!----------------------------------------------------------------------
[5836]	523	!
[3764]	524	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
	525	! used to prevent the applied increments taking the temperature below the local freezing point
[4990]	526	DO jk = 1, jpkm1
[6140]	527	CALL eos_fzp( tsn(:,:,jk,jp_sal), fzptnz(:,:,jk), gdept_n(:,:,jk) )
[4990]	528	END DO
[5836]	529	!
	530	! !--------------------------------------
	531	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	532	! !--------------------------------------
	533	!
[2128]	534	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	535	!
[2128]	536	it = kt - nit000 + 1
	537	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
[5836]	538	!
[2128]	539	IF(lwp) THEN
	540	WRITE(numout,*)
[4990]	541	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
[2128]	542	WRITE(numout,*) '~~~~~~~~~~~~'
	543	ENDIF
[5836]	544	!
[2128]	545	! Update the tracer tendencies
	546	DO jk = 1, jpkm1
[3764]	547	IF (ln_temnofreeze) THEN
	548	! Do not apply negative increments if the temperature will fall below freezing
	549	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
	550	& tsn(:,:,jk,jp_tem) + tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
	551	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
	552	END WHERE
	553	ELSE
	554	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
	555	ENDIF
	556	IF (ln_salfix) THEN
	557	! Do not apply negative increments if the salinity will fall below a specified
	558	! minimum value salfixmin
	559	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
	560	& tsn(:,:,jk,jp_sal) + tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
	561	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
	562	END WHERE
	563	ELSE
	564	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
	565	ENDIF
[2128]	566	END DO
[5836]	567	!
[2128]	568	ENDIF
[5836]	569	!
[2128]	570	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
	571	DEALLOCATE( t_bkginc )
	572	DEALLOCATE( s_bkginc )
	573	ENDIF
[5836]	574	! !--------------------------------------
	575	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	576	! !--------------------------------------
	577	!
[2128]	578	IF ( kt == nitdin_r ) THEN
[5836]	579	!
[2128]	580	neuler = 0 ! Force Euler forward step
[5836]	581	!
[2128]	582	! Initialize the now fields with the background + increment
[3764]	583	IF (ln_temnofreeze) THEN
	584	! Do not apply negative increments if the temperature will fall below freezing
[4990]	585	WHERE( t_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
[3764]	586	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
	587	END WHERE
	588	ELSE
	589	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
	590	ENDIF
[2128]	591	IF (ln_salfix) THEN
[3764]	592	! Do not apply negative increments if the salinity will fall below a specified
	593	! minimum value salfixmin
[4990]	594	WHERE( s_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
[3764]	595	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
	596	END WHERE
	597	ELSE
	598	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
[2128]	599	ENDIF
	600
[4990]	601	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
[2128]	602
[4990]	603	CALL eos( tsb, rhd, rhop, gdept_0(:,:,:) ) ! Before potential and in situ densities
	604	!!gm fabien
	605	! CALL eos( tsb, rhd, rhop ) ! Before potential and in situ densities
	606	!!gm
	607
[6140]	608	IF( ln_zps .AND. .NOT. lk_c1d .AND. .NOT. ln_isfcav) &
	609	& CALL zps_hde ( kt, jpts, tsb, gtsu, gtsv, & ! Partial steps: before horizontal gradient
	610	& rhd, gru , grv ) ! of t, s, rd at the last ocean level
	611	IF( ln_zps .AND. .NOT. lk_c1d .AND. ln_isfcav) &
	612	& CALL zps_hde_isf( nit000, jpts, tsb, gtsu, gtsv, gtui, gtvi, & ! Partial steps for top cell (ISF)
	613	& rhd, gru , grv , grui, grvi ) ! of t, s, rd at the last ocean level
	614
[2128]	615	DEALLOCATE( t_bkginc )
	616	DEALLOCATE( s_bkginc )
	617	DEALLOCATE( t_bkg )
	618	DEALLOCATE( s_bkg )
	619	ENDIF
[2392]	620	!
[2128]	621	ENDIF
[3764]	622	! Perhaps the following call should be in step
[5836]	623	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
[2392]	624	!
[2128]	625	END SUBROUTINE tra_asm_inc
	626
[2392]	627
[2128]	628	SUBROUTINE dyn_asm_inc( kt )
	629	!!----------------------------------------------------------------------
	630	!! * ROUTINE dyn_asm_inc *
	631	!!
	632	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
	633	!!
	634	!! ** Method : Direct initialization or Incremental Analysis Updating.
	635	!!
	636	!! ** Action :
	637	!!----------------------------------------------------------------------
	638	INTEGER, INTENT(IN) :: kt ! Current time step
[2392]	639	!
[2128]	640	INTEGER :: jk
	641	INTEGER :: it
	642	REAL(wp) :: zincwgt ! IAU weight for current time step
[2392]	643	!!----------------------------------------------------------------------
[5836]	644	!
	645	! !--------------------------------------------
	646	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	647	! !--------------------------------------------
	648	!
[2128]	649	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	650	!
[2128]	651	it = kt - nit000 + 1
	652	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
[5836]	653	!
[2128]	654	IF(lwp) THEN
	655	WRITE(numout,*)
[5836]	656	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
[2128]	657	WRITE(numout,*) '~~~~~~~~~~~~'
	658	ENDIF
[5836]	659	!
[2128]	660	! Update the dynamic tendencies
	661	DO jk = 1, jpkm1
	662	ua(:,:,jk) = ua(:,:,jk) + u_bkginc(:,:,jk) * zincwgt
	663	va(:,:,jk) = va(:,:,jk) + v_bkginc(:,:,jk) * zincwgt
	664	END DO
[5836]	665	!
[2128]	666	IF ( kt == nitiaufin_r ) THEN
	667	DEALLOCATE( u_bkginc )
	668	DEALLOCATE( v_bkginc )
	669	ENDIF
[5836]	670	!
[2128]	671	ENDIF
[5836]	672	! !-----------------------------------------
	673	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	674	! !-----------------------------------------
	675	!
[2128]	676	IF ( kt == nitdin_r ) THEN
[5836]	677	!
[2128]	678	neuler = 0 ! Force Euler forward step
[5836]	679	!
[2128]	680	! Initialize the now fields with the background + increment
	681	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
	682	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
[5836]	683	!
[2128]	684	ub(:,:,:) = un(:,:,:) ! Update before fields
	685	vb(:,:,:) = vn(:,:,:)
[5836]	686	!
[2128]	687	DEALLOCATE( u_bkg )
	688	DEALLOCATE( v_bkg )
	689	DEALLOCATE( u_bkginc )
	690	DEALLOCATE( v_bkginc )
	691	ENDIF
[2392]	692	!
[2128]	693	ENDIF
[2392]	694	!
[2128]	695	END SUBROUTINE dyn_asm_inc
	696
[2392]	697
[2128]	698	SUBROUTINE ssh_asm_inc( kt )
	699	!!----------------------------------------------------------------------
	700	!! * ROUTINE ssh_asm_inc *
	701	!!
	702	!! ** Purpose : Apply the sea surface height assimilation increment.
	703	!!
	704	!! ** Method : Direct initialization or Incremental Analysis Updating.
	705	!!
	706	!! ** Action :
	707	!!----------------------------------------------------------------------
	708	INTEGER, INTENT(IN) :: kt ! Current time step
[2392]	709	!
[2128]	710	INTEGER :: it
[3764]	711	INTEGER :: jk
[2128]	712	REAL(wp) :: zincwgt ! IAU weight for current time step
[2392]	713	!!----------------------------------------------------------------------
[5836]	714	!
	715	! !-----------------------------------------
	716	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	717	! !-----------------------------------------
	718	!
[2128]	719	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	720	!
[2128]	721	it = kt - nit000 + 1
	722	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
[5836]	723	!
[2128]	724	IF(lwp) THEN
	725	WRITE(numout,*)
	726	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
	727	& kt,' with IAU weight = ', wgtiau(it)
	728	WRITE(numout,*) '~~~~~~~~~~~~'
	729	ENDIF
[5836]	730	!
[2128]	731	! Save the tendency associated with the IAU weighted SSH increment
	732	! (applied in dynspg.*)
	733	#if defined key_asminc
	734	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
	735	#endif
	736	IF ( kt == nitiaufin_r ) THEN
	737	DEALLOCATE( ssh_bkginc )
	738	ENDIF
[5836]	739	!
[8552]	740	#if defined key_asminc
[8547]	741	ELSE IF( kt == nitiaufin_r+1 ) THEN
[8546]	742	!
	743	ssh_iau(:,:) = 0._wp
	744	!
[8552]	745	#endif
[2128]	746	ENDIF
[5836]	747	! !-----------------------------------------
	748	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	749	! !-----------------------------------------
	750	!
[2128]	751	IF ( kt == nitdin_r ) THEN
[5836]	752	!
	753	neuler = 0 ! Force Euler forward step
	754	!
	755	sshn(:,:) = ssh_bkg(:,:) + ssh_bkginc(:,:) ! Initialize the now fields the background + increment
	756	!
	757	sshb(:,:) = sshn(:,:) ! Update before fields
[6140]	758	e3t_b(:,:,:) = e3t_n(:,:,:)
	759	!!gm why not e3u_b, e3v_b, gdept_b ????
[5836]	760	!
[2128]	761	DEALLOCATE( ssh_bkg )
	762	DEALLOCATE( ssh_bkginc )
[5836]	763	!
[2128]	764	ENDIF
[2392]	765	!
[2128]	766	ENDIF
[2392]	767	!
[2128]	768	END SUBROUTINE ssh_asm_inc
	769
[9213]	770
[9023]	771	SUBROUTINE ssh_asm_div( kt, phdivn )
	772	!!----------------------------------------------------------------------
	773	!! * ROUTINE ssh_asm_div *
	774	!!
	775	!! ** Purpose : ssh increment with z* is incorporated via a correction of the local divergence
	776	!! across all the water column
	777	!!
	778	!! ** Method :
	779	!! CAUTION : sshiau is positive (inflow) decreasing the
	780	!! divergence and expressed in m/s
	781	!!
	782	!! ** Action : phdivn decreased by the ssh increment
	783	!!----------------------------------------------------------------------
	784	INTEGER, INTENT(IN) :: kt ! ocean time-step index
	785	REAL(wp), DIMENSION(:,:,:), INTENT(inout) :: phdivn ! horizontal divergence
	786	!!
	787	INTEGER :: jk ! dummy loop index
	788	REAL(wp), DIMENSION(:,:) , POINTER :: ztim ! local array
	789	!!----------------------------------------------------------------------
	790	!
	791	#if defined key_asminc
	792	CALL ssh_asm_inc( kt ) !== (calculate increments)
	793	!
	794	IF( ln_linssh ) THEN
	795	phdivn(:,:,1) = phdivn(:,:,1) - ssh_iau(:,:) / e3t_n(:,:,1) * tmask(:,:,1)
	796	ELSE
[9044]	797	ALLOCATE( ztim(jpi,jpj) )
[9023]	798	ztim(:,:) = ssh_iau(:,:) / ( ht_n(:,:) + 1.0 - ssmask(:,:) )
	799	DO jk = 1, jpkm1
	800	phdivn(:,:,jk) = phdivn(:,:,jk) - ztim(:,:) * tmask(:,:,jk)
	801	END DO
	802	!
[9044]	803	DEALLOCATE(ztim)
[9023]	804	ENDIF
	805	#endif
	806	!
	807	END SUBROUTINE ssh_asm_div
[3785]	808
[9213]	809
[3764]	810	SUBROUTINE seaice_asm_inc( kt, kindic )
	811	!!----------------------------------------------------------------------
	812	!! * ROUTINE seaice_asm_inc *
	813	!!
	814	!! ** Purpose : Apply the sea ice assimilation increment.
	815	!!
	816	!! ** Method : Direct initialization or Incremental Analysis Updating.
	817	!!
	818	!! ** Action :
	819	!!
	820	!!----------------------------------------------------------------------
[5836]	821	INTEGER, INTENT(in) :: kt ! Current time step
[3785]	822	INTEGER, INTENT(in), OPTIONAL :: kindic ! flag for disabling the deallocation
	823	!
	824	INTEGER :: it
	825	REAL(wp) :: zincwgt ! IAU weight for current time step
[9019]	826	#if defined key_lim3
[3785]	827	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
	828	REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
[3764]	829	#endif
[3785]	830	!!----------------------------------------------------------------------
[5836]	831	!
	832	! !-----------------------------------------
	833	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	834	! !-----------------------------------------
	835	!
[3764]	836	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	837	!
[3764]	838	it = kt - nit000 + 1
	839	zincwgt = wgtiau(it) ! IAU weight for the current time step
	840	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
[5836]	841	!
[3764]	842	IF(lwp) THEN
	843	WRITE(numout,*)
[5836]	844	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
[3764]	845	WRITE(numout,*) '~~~~~~~~~~~~'
	846	ENDIF
[5836]	847	!
[9019]	848	! Sea-ice : LIM-3 case
[5836]	849	!
[9019]	850	#if defined key_lim3
	851	zofrld (:,:) = 1._wp - at_i(:,:)
	852	zohicif(:,:) = hm_i(:,:)
[3785]	853	!
[9019]	854	at_i (:,:) = 1. - MIN( MAX( 1.-at_i (:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
	855	at_i_b(:,:) = 1. - MIN( MAX( 1.-at_i_b(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
	856	fr_i(:,:) = at_i(:,:) ! adjust ice fraction
[3785]	857	!
[9019]	858	zseaicendg(:,:) = zofrld(:,:) - (1. - at_i(:,:)) ! find out actual sea ice nudge applied
[3785]	859	!
[3764]	860	! Nudge sea ice depth to bring it up to a required minimum depth
[9019]	861	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hm_i(:,:) < zhicifmin )
	862	zhicifinc(:,:) = (zhicifmin - hm_i(:,:)) * zincwgt
[3764]	863	ELSEWHERE
	864	zhicifinc(:,:) = 0.0_wp
	865	END WHERE
[3785]	866	!
	867	! nudge ice depth
[9019]	868	hm_i (:,:) = hm_i (:,:) + zhicifinc(:,:)
[3785]	869	!
	870	! seaice salinity balancing (to add)
[3764]	871	#endif
[9213]	872	!
[4245]	873	#if defined key_cice && defined key_asminc
[3785]	874	! Sea-ice : CICE case. Pass ice increment tendency into CICE
[3764]	875	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
	876	#endif
[9213]	877	!
[3764]	878	IF ( kt == nitiaufin_r ) THEN
	879	DEALLOCATE( seaice_bkginc )
	880	ENDIF
[9213]	881	!
[3764]	882	ELSE
[9213]	883	!
[4245]	884	#if defined key_cice && defined key_asminc
[5836]	885	ndaice_da(:,:) = 0._wp ! Sea-ice : CICE case. Zero ice increment tendency into CICE
[3764]	886	#endif
[9213]	887	!
[3764]	888	ENDIF
[5836]	889	! !-----------------------------------------
	890	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	891	! !-----------------------------------------
	892	!
[3764]	893	IF ( kt == nitdin_r ) THEN
[5836]	894	!
[3764]	895	neuler = 0 ! Force Euler forward step
[5836]	896	!
[9019]	897	! Sea-ice : LIM-3 case
[5836]	898	!
[9019]	899	#if defined key_lim3
	900	zofrld (:,:) = 1._wp - at_i(:,:)
	901	zohicif(:,:) = hm_i(:,:)
[3785]	902	!
[3764]	903	! Initialize the now fields the background + increment
[9019]	904	at_i(:,:) = 1. - MIN( MAX( 1.-at_i(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
	905	at_i_b(:,:) = at_i(:,:)
	906	fr_i(:,:) = at_i(:,:) ! adjust ice fraction
[3785]	907	!
[9019]	908	zseaicendg(:,:) = zofrld(:,:) - (1. - at_i(:,:)) ! find out actual sea ice nudge applied
	909	!
[3764]	910	! Nudge sea ice depth to bring it up to a required minimum depth
[9019]	911	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hm_i(:,:) < zhicifmin )
	912	zhicifinc(:,:) = (zhicifmin - hm_i(:,:)) * zincwgt
[3764]	913	ELSEWHERE
[9019]	914	zhicifinc(:,:) = 0.0_wp
[3764]	915	END WHERE
[3785]	916	!
	917	! nudge ice depth
[9019]	918	hm_i (:,:) = hm_i (:,:) + zhicifinc(:,:)
[3785]	919	!
	920	! seaice salinity balancing (to add)
[3764]	921	#endif
[5836]	922	!
[4245]	923	#if defined key_cice && defined key_asminc
	924	! Sea-ice : CICE case. Pass ice increment tendency into CICE
[3764]	925	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
	926	#endif
[5836]	927	IF ( .NOT. PRESENT(kindic) ) THEN
	928	DEALLOCATE( seaice_bkginc )
	929	END IF
	930	!
[3764]	931	ELSE
[5836]	932	!
	933	#if defined key_cice && defined key_asminc
	934	ndaice_da(:,:) = 0._wp ! Sea-ice : CICE case. Zero ice increment tendency into CICE
[3764]	935	#endif
[5836]	936	!
[3764]	937	ENDIF
	938
[9019]	939	!#if defined defined key_lim3 \|\| defined key_cice
[3764]	940	!
	941	! IF (ln_seaicebal ) THEN
	942	! !! balancing salinity increments
	943	! !! simple case from limflx.F90 (doesn't include a mass flux)
	944	! !! assumption is that as ice concentration is reduced or increased
	945	! !! the snow and ice depths remain constant
	946	! !! note that snow is being created where ice concentration is being increased
	947	! !! - could be more sophisticated and
	948	! !! not do this (but would need to alter h_snow)
	949	!
	950	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
	951	!
	952	! DO jj = 1, jpj
	953	! DO ji = 1, jpi
	954	! ! calculate change in ice and snow mass per unit area
	955	! ! positive values imply adding salt to the ocean (results from ice formation)
	956	! ! fwf : ice formation and melting
	957	!
	958	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
	959	!
	960	! ! change salinity down to mixed layer depth
	961	! mld=hmld_kara(ji,jj)
	962	!
	963	! ! prevent small mld
	964	! ! less than 10m can cause salinity instability
	965	! IF (mld < 10) mld=10
	966	!
	967	! ! set to bottom of a level
	968	! DO jk = jpk-1, 2, -1
	969	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
	970	! mld=gdepw(ji,jj,jk+1)
	971	! jkmax=jk
	972	! ENDIF
	973	! ENDDO
	974	!
	975	! ! avoid applying salinity balancing in shallow water or on land
	976	! !
	977	!
	978	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
	979	!
	980	! dsal_ocn=0.0_wp
	981	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
	982	!
	983	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
	984	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
	985	!
	986	! ! put increments in for levels in the mixed layer
	987	! ! but prevent salinity below a threshold value
	988	!
	989	! DO jk = 1, jkmax
	990	!
	991	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
	992	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
	993	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
	994	! ENDIF
	995	!
	996	! ENDDO
	997	!
	998	! ! ! salt exchanges at the ice/ocean interface
	999	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
	1000	! !
	1001	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
	1002	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
	1003	! !!
	1004	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
	1005	! !! ! E-P (kg m-2 s-2)
	1006	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
	1007	! ENDDO !ji
	1008	! ENDDO !jj!
	1009	!
	1010	! ENDIF !ln_seaicebal
	1011	!
	1012	!#endif
[5836]	1013	!
[3764]	1014	ENDIF
[5836]	1015	!
[3764]	1016	END SUBROUTINE seaice_asm_inc
[3785]	1017
[2392]	1018	!!======================================================================
[2128]	1019	END MODULE asminc

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