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asminc.F90 in NEMO/trunk/src/OCE/ASM – NEMO

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source: NEMO/trunk/src/OCE/ASM/asminc.F90 @ 13226

Last change on this file since 13226 was 13226, checked in by orioltp, 4 years ago
Merging dev_r12512_HPC-04_mcastril_Mixed_Precision_implementation into the trunk
Property svn:keywords set to `Id`
File size: 48.6 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
[9254]	33	USE asmbkg !
[9019]	34	USE c1d ! 1D initialization
	35	USE sbc_oce ! Surface boundary condition variables.
	36	USE diaobs , ONLY : calc_date ! Compute the calendar date on a given step
[9570]	37	#if defined key_si3
[9019]	38	USE ice , ONLY : hm_i, at_i, at_i_b
[3764]	39	#endif
[9019]	40	!
	41	USE in_out_manager ! I/O manager
	42	USE iom ! Library to read input files
	43	USE lib_mpp ! MPP library
[2128]	44
	45	IMPLICIT NONE
	46	PRIVATE
[2392]	47
	48	PUBLIC asm_inc_init !: Initialize the increment arrays and IAU weights
	49	PUBLIC tra_asm_inc !: Apply the tracer (T and S) increments
	50	PUBLIC dyn_asm_inc !: Apply the dynamic (u and v) increments
	51	PUBLIC ssh_asm_inc !: Apply the SSH increment
[9023]	52	PUBLIC ssh_asm_div !: Apply the SSH divergence
[3764]	53	PUBLIC seaice_asm_inc !: Apply the seaice increment
[2128]	54
	55	#if defined key_asminc
[2392]	56	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
[2128]	57	#else
[2392]	58	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
[2128]	59	#endif
[5836]	60	LOGICAL, PUBLIC :: ln_bkgwri !: No output of the background state fields
	61	LOGICAL, PUBLIC :: ln_asmiau !: No applying forcing with an assimilation increment
	62	LOGICAL, PUBLIC :: ln_asmdin !: No direct initialization
	63	LOGICAL, PUBLIC :: ln_trainc !: No tracer (T and S) assimilation increments
	64	LOGICAL, PUBLIC :: ln_dyninc !: No dynamics (u and v) assimilation increments
	65	LOGICAL, PUBLIC :: ln_sshinc !: No sea surface height assimilation increment
	66	LOGICAL, PUBLIC :: ln_seaiceinc !: No sea ice concentration increment
	67	LOGICAL, PUBLIC :: ln_salfix !: Apply minimum salinity check
[3764]	68	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
[5836]	69	INTEGER, PUBLIC :: nn_divdmp !: Apply divergence damping filter nn_divdmp times
[2128]	70
[2392]	71	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkg , s_bkg !: Background temperature and salinity
	72	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkg , v_bkg !: Background u- & v- velocity components
	73	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkginc, s_bkginc !: Increment to the background T & S
	74	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkginc, v_bkginc !: Increment to the u- & v-components
	75	REAL(wp), PUBLIC, DIMENSION(:) , ALLOCATABLE :: wgtiau !: IAU weights for each time step
[2128]	76	#if defined key_asminc
[9213]	77	REAL(wp), PUBLIC, DIMENSION(:,:) , ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
[2128]	78	#endif
[2392]	79	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
	80	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
	81	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
	82	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
	83	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
	84	!
	85	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
	86	! !: = 1 Linear hat-like, centred in middle of IAU interval
	87	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
[2128]	88
[2392]	89	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
[3764]	90	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
[8030]	91	#if defined key_cice && defined key_asminc
	92	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ndaice_da ! ice increment tendency into CICE
	93	#endif
[2128]	94
[3294]	95	!! * Substitutions
[12377]	96	# include "do_loop_substitute.h90"
[2287]	97	!!----------------------------------------------------------------------
[9598]	98	!! NEMO/OCE 4.0 , NEMO Consortium (2018)
[2287]	99	!! $Id$
[10068]	100	!! Software governed by the CeCILL license (see ./LICENSE)
[2287]	101	!!----------------------------------------------------------------------
[2128]	102	CONTAINS
	103
[12377]	104	SUBROUTINE asm_inc_init( Kbb, Kmm, Krhs )
[2128]	105	!!----------------------------------------------------------------------
	106	!! * ROUTINE asm_inc_init *
	107	!!
	108	!! ** Purpose : Initialize the assimilation increment and IAU weights.
	109	!!
	110	!! ** Method : Initialize the assimilation increment and IAU weights.
	111	!!
	112	!! ** Action :
	113	!!----------------------------------------------------------------------
[12377]	114	INTEGER, INTENT(in) :: Kbb, Kmm, Krhs ! time level indices
	115	!
[4990]	116	INTEGER :: ji, jj, jk, jt ! dummy loop indices
	117	INTEGER :: imid, inum ! local integers
	118	INTEGER :: ios ! Local integer output status for namelist read
[2128]	119	INTEGER :: iiauper ! Number of time steps in the IAU period
	120	INTEGER :: icycper ! Number of time steps in the cycle
[6140]	121	REAL(KIND=dp) :: ditend_date ! Date YYYYMMDD.HHMMSS of final time step
	122	REAL(KIND=dp) :: ditbkg_date ! Date YYYYMMDD.HHMMSS of background time step for Jb term
	123	REAL(KIND=dp) :: ditdin_date ! Date YYYYMMDD.HHMMSS of background time step for DI
	124	REAL(KIND=dp) :: ditiaustr_date ! Date YYYYMMDD.HHMMSS of IAU interval start time step
	125	REAL(KIND=dp) :: ditiaufin_date ! Date YYYYMMDD.HHMMSS of IAU interval final time step
	126
[2128]	127	REAL(wp) :: znorm ! Normalization factor for IAU weights
[4990]	128	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights (should be equal to one)
[2128]	129	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
	130	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
	131	REAL(wp) :: zdate_bkg ! Date in background state file for DI
	132	REAL(wp) :: zdate_inc ! Time axis in increments file
[4990]	133	!
[9019]	134	REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: zhdiv ! 2D workspace
[2392]	135	!!
[3764]	136	NAMELIST/nam_asminc/ ln_bkgwri, &
[2392]	137	& ln_trainc, ln_dyninc, ln_sshinc, &
	138	& ln_asmdin, ln_asmiau, &
	139	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
[4990]	140	& ln_salfix, salfixmin, nn_divdmp
[2392]	141	!!----------------------------------------------------------------------
[2128]	142
	143	!-----------------------------------------------------------------------
	144	! Read Namelist nam_asminc : assimilation increment interface
	145	!-----------------------------------------------------------------------
[5836]	146	ln_seaiceinc = .FALSE.
[3764]	147	ln_temnofreeze = .FALSE.
[2128]	148
[4147]	149	READ ( numnam_ref, nam_asminc, IOSTAT = ios, ERR = 901)
[11536]	150	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in reference namelist' )
[4147]	151	READ ( numnam_cfg, nam_asminc, IOSTAT = ios, ERR = 902 )
[11536]	152	902 IF( ios > 0 ) CALL ctl_nam ( ios , 'nam_asminc in configuration namelist' )
[4624]	153	IF(lwm) WRITE ( numond, nam_asminc )
[4147]	154
[2128]	155	! Control print
	156	IF(lwp) THEN
	157	WRITE(numout,*)
	158	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
	159	WRITE(numout,*) '~~~~~~~~~~~~'
[2392]	160	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
	161	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
	162	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
	163	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
	164	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
	165	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
[3764]	166	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
[2392]	167	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
	168	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
	169	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
	170	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
	171	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
	172	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
	173	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
	174	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
[2128]	175	ENDIF
	176
[9019]	177	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
	178	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
	179	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
	180	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
[2128]	181
[9019]	182	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
	183	icycper = nitend - nit000 + 1 ! Cycle interval length
[2128]	184
[9019]	185	CALL calc_date( nitend , ditend_date ) ! Date of final time step
	186	CALL calc_date( nitbkg_r , ditbkg_date ) ! Background time for Jb referenced to ndate0
	187	CALL calc_date( nitdin_r , ditdin_date ) ! Background time for DI referenced to ndate0
	188	CALL calc_date( nitiaustr_r, ditiaustr_date ) ! IAU start time referenced to ndate0
	189	CALL calc_date( nitiaufin_r, ditiaufin_date ) ! IAU end time referenced to ndate0
[6140]	190
[2128]	191	IF(lwp) THEN
	192	WRITE(numout,*)
	193	WRITE(numout,*) ' Time steps referenced to current cycle:'
	194	WRITE(numout,*) ' iitrst = ', nit000 - 1
	195	WRITE(numout,*) ' nit000 = ', nit000
	196	WRITE(numout,*) ' nitend = ', nitend
	197	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
	198	WRITE(numout,*) ' nitdin_r = ', nitdin_r
	199	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
	200	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
	201	WRITE(numout,*)
	202	WRITE(numout,*) ' Dates referenced to current cycle:'
	203	WRITE(numout,*) ' ndastp = ', ndastp
	204	WRITE(numout,*) ' ndate0 = ', ndate0
[6140]	205	WRITE(numout,*) ' nn_time0 = ', nn_time0
	206	WRITE(numout,*) ' ditend_date = ', ditend_date
	207	WRITE(numout,*) ' ditbkg_date = ', ditbkg_date
	208	WRITE(numout,*) ' ditdin_date = ', ditdin_date
	209	WRITE(numout,*) ' ditiaustr_date = ', ditiaustr_date
	210	WRITE(numout,*) ' ditiaufin_date = ', ditiaufin_date
[2128]	211	ENDIF
	212
	213
	214	IF ( ( ln_asmdin ).AND.( ln_asmiau ) ) &
	215	& CALL ctl_stop( ' ln_asmdin and ln_asmiau :', &
	216	& ' Choose Direct Initialization OR Incremental Analysis Updating')
	217
	218	IF ( ( ( .NOT. ln_asmdin ).AND.( .NOT. ln_asmiau ) ) &
[3764]	219	.AND.( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ) .OR. ( ln_seaiceinc) )) &
	220	& CALL ctl_stop( ' One or more of ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc is set to .true.', &
[2128]	221	& ' but ln_asmdin and ln_asmiau are both set to .false. :', &
	222	& ' Inconsistent options')
	223
	224	IF ( ( niaufn /= 0 ).AND.( niaufn /= 1 ) ) &
	225	& CALL ctl_stop( ' niaufn /= 0 or niaufn /=1 :', &
	226	& ' Type IAU weighting function is invalid')
	227
[3764]	228	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ).AND.( .NOT. ln_seaiceinc ) &
[2128]	229	& ) &
[3764]	230	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc are set to .false. :', &
[2128]	231	& ' The assimilation increments are not applied')
	232
	233	IF ( ( ln_asmiau ).AND.( nitiaustr == nitiaufin ) ) &
	234	& CALL ctl_stop( ' nitiaustr = nitiaufin :', &
	235	& ' IAU interval is of zero length')
	236
	237	IF ( ( ln_asmiau ).AND.( ( nitiaustr_r < nit000 ).OR.( nitiaufin_r > nitend ) ) ) &
	238	& CALL ctl_stop( ' nitiaustr or nitiaufin :', &
	239	& ' IAU starting or final time step is outside the cycle interval', &
	240	& ' Valid range nit000 to nitend')
	241
	242	IF ( ( nitbkg_r < nit000 - 1 ).OR.( nitbkg_r > nitend ) ) &
	243	& CALL ctl_stop( ' nitbkg :', &
	244	& ' Background time step is outside the cycle interval')
	245
	246	IF ( ( nitdin_r < nit000 - 1 ).OR.( nitdin_r > nitend ) ) &
	247	& CALL ctl_stop( ' nitdin :', &
	248	& ' Background time step for Direct Initialization is outside', &
	249	& ' the cycle interval')
	250
	251	IF ( nstop > 0 ) RETURN ! if there are any errors then go no further
	252
	253	!--------------------------------------------------------------------
	254	! Initialize the Incremental Analysis Updating weighting function
	255	!--------------------------------------------------------------------
	256
[9213]	257	IF( ln_asmiau ) THEN
	258	!
[2128]	259	ALLOCATE( wgtiau( icycper ) )
[9213]	260	!
[9019]	261	wgtiau(:) = 0._wp
[9213]	262	!
	263	! !---------------------------------------------------------
	264	IF( niaufn == 0 ) THEN ! Constant IAU forcing
	265	! !---------------------------------------------------------
[2128]	266	DO jt = 1, iiauper
	267	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
	268	END DO
[9213]	269	! !---------------------------------------------------------
	270	ELSEIF ( niaufn == 1 ) THEN ! Linear hat-like, centred in middle of IAU interval
	271	! !---------------------------------------------------------
[2128]	272	! Compute the normalization factor
[9213]	273	znorm = 0._wp
	274	IF( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
[2128]	275	imid = iiauper / 2
	276	DO jt = 1, imid
	277	znorm = znorm + REAL( jt )
	278	END DO
	279	znorm = 2.0 * znorm
[9213]	280	ELSE ! Odd number of time steps in IAU interval
[2128]	281	imid = ( iiauper + 1 ) / 2
	282	DO jt = 1, imid - 1
	283	znorm = znorm + REAL( jt )
	284	END DO
	285	znorm = 2.0 * znorm + REAL( imid )
	286	ENDIF
	287	znorm = 1.0 / znorm
[9213]	288	!
[2128]	289	DO jt = 1, imid - 1
	290	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
	291	END DO
	292	DO jt = imid, iiauper
	293	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
	294	END DO
[9213]	295	!
[2128]	296	ENDIF
	297
	298	! Test that the integral of the weights over the weighting interval equals 1
	299	IF(lwp) THEN
	300	WRITE(numout,*)
	301	WRITE(numout,*) 'asm_inc_init : IAU weights'
	302	WRITE(numout,*) '~~~~~~~~~~~~'
	303	WRITE(numout,*) ' time step IAU weight'
	304	WRITE(numout,*) ' ========= ====================='
	305	ztotwgt = 0.0
	306	DO jt = 1, icycper
	307	ztotwgt = ztotwgt + wgtiau(jt)
	308	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
	309	END DO
	310	WRITE(numout,*) ' ==================================='
	311	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
	312	WRITE(numout,*) ' ==================================='
	313	ENDIF
	314
	315	ENDIF
	316
	317	!--------------------------------------------------------------------
	318	! Allocate and initialize the increment arrays
	319	!--------------------------------------------------------------------
	320
[9213]	321	ALLOCATE( t_bkginc (jpi,jpj,jpk) ) ; t_bkginc (:,:,:) = 0._wp
	322	ALLOCATE( s_bkginc (jpi,jpj,jpk) ) ; s_bkginc (:,:,:) = 0._wp
	323	ALLOCATE( u_bkginc (jpi,jpj,jpk) ) ; u_bkginc (:,:,:) = 0._wp
	324	ALLOCATE( v_bkginc (jpi,jpj,jpk) ) ; v_bkginc (:,:,:) = 0._wp
	325	ALLOCATE( ssh_bkginc (jpi,jpj) ) ; ssh_bkginc (:,:) = 0._wp
	326	ALLOCATE( seaice_bkginc(jpi,jpj) ) ; seaice_bkginc(:,:) = 0._wp
[2128]	327	#if defined key_asminc
[9213]	328	ALLOCATE( ssh_iau (jpi,jpj) ) ; ssh_iau (:,:) = 0._wp
[2128]	329	#endif
[8030]	330	#if defined key_cice && defined key_asminc
[9213]	331	ALLOCATE( ndaice_da (jpi,jpj) ) ; ndaice_da (:,:) = 0._wp
[8030]	332	#endif
[9213]	333	!
	334	IF ( ln_trainc .OR. ln_dyninc .OR. & !--------------------------------------
	335	& ln_sshinc .OR. ln_seaiceinc ) THEN ! Read the increments from file
	336	! !--------------------------------------
[2128]	337	CALL iom_open( c_asminc, inum )
[9213]	338	!
	339	CALL iom_get( inum, 'time' , zdate_inc )
[2128]	340	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
	341	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
	342	z_inc_dateb = zdate_inc
	343	z_inc_datef = zdate_inc
[9213]	344	!
[2128]	345	IF(lwp) THEN
	346	WRITE(numout,*)
[9213]	347	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid between dates ', z_inc_dateb,' and ', z_inc_datef
[2128]	348	WRITE(numout,*) '~~~~~~~~~~~~'
	349	ENDIF
[9213]	350	!
	351	IF ( ( z_inc_dateb < ndastp + nn_time0*0.0001_wp ) .OR. &
	352	& ( z_inc_datef > ditend_date ) ) &
	353	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
	354	& ' outside the assimilation interval' )
[2128]	355
[6140]	356	IF ( ( ln_asmdin ).AND.( zdate_inc /= ditdin_date ) ) &
[2128]	357	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
	358	& ' not agree with Direct Initialization time' )
	359
	360	IF ( ln_trainc ) THEN
	361	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
	362	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
	363	! Apply the masks
	364	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
	365	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
	366	! Set missing increments to 0.0 rather than 1e+20
	367	! to allow for differences in masks
	368	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
	369	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
	370	ENDIF
	371
	372	IF ( ln_dyninc ) THEN
	373	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
	374	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
	375	! Apply the masks
	376	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
	377	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
	378	! Set missing increments to 0.0 rather than 1e+20
	379	! to allow for differences in masks
	380	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
	381	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
	382	ENDIF
	383
	384	IF ( ln_sshinc ) THEN
	385	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
	386	! Apply the masks
	387	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
	388	! Set missing increments to 0.0 rather than 1e+20
	389	! to allow for differences in masks
	390	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
	391	ENDIF
	392
[3764]	393	IF ( ln_seaiceinc ) THEN
	394	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
	395	! Apply the masks
	396	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
	397	! Set missing increments to 0.0 rather than 1e+20
	398	! to allow for differences in masks
	399	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
	400	ENDIF
[9213]	401	!
[2128]	402	CALL iom_close( inum )
[9213]	403	!
[2128]	404	ENDIF
[9213]	405	!
	406	! !--------------------------------------
	407	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN ! Apply divergence damping filter
	408	! !--------------------------------------
[9019]	409	ALLOCATE( zhdiv(jpi,jpj) )
[5836]	410	!
	411	DO jt = 1, nn_divdmp
	412	!
[9019]	413	DO jk = 1, jpkm1 ! zhdiv = e1e1 * div
	414	zhdiv(:,:) = 0._wp
[12377]	415	DO_2D_00_00
	416	zhdiv(ji,jj) = ( e2u(ji ,jj) * e3u(ji ,jj,jk,Kmm) * u_bkginc(ji ,jj,jk) &
	417	& - e2u(ji-1,jj) * e3u(ji-1,jj,jk,Kmm) * u_bkginc(ji-1,jj,jk) &
	418	& + e1v(ji,jj ) * e3v(ji,jj ,jk,Kmm) * v_bkginc(ji,jj ,jk) &
	419	& - e1v(ji,jj-1) * e3v(ji,jj-1,jk,Kmm) * v_bkginc(ji,jj-1,jk) ) / e3t(ji,jj,jk,Kmm)
	420	END_2D
[13226]	421	CALL lbc_lnk( 'asminc', zhdiv, 'T', 1.0_wp ) ! lateral boundary cond. (no sign change)
[5836]	422	!
[12377]	423	DO_2D_00_00
	424	u_bkginc(ji,jj,jk) = u_bkginc(ji,jj,jk) &
	425	& + 0.2_wp * ( zhdiv(ji+1,jj) - zhdiv(ji ,jj) ) * r1_e1u(ji,jj) * umask(ji,jj,jk)
	426	v_bkginc(ji,jj,jk) = v_bkginc(ji,jj,jk) &
	427	& + 0.2_wp * ( zhdiv(ji,jj+1) - zhdiv(ji,jj ) ) * r1_e2v(ji,jj) * vmask(ji,jj,jk)
	428	END_2D
[3294]	429	END DO
[5836]	430	!
[3764]	431	END DO
[5836]	432	!
[9019]	433	DEALLOCATE( zhdiv )
[5836]	434	!
[3294]	435	ENDIF
[9213]	436	!
	437	! !-----------------------------------------------------
	438	IF ( ln_asmdin ) THEN ! Allocate and initialize the background state arrays
	439	! !-----------------------------------------------------
[5836]	440	!
[9213]	441	ALLOCATE( t_bkg (jpi,jpj,jpk) ) ; t_bkg (:,:,:) = 0._wp
	442	ALLOCATE( s_bkg (jpi,jpj,jpk) ) ; s_bkg (:,:,:) = 0._wp
	443	ALLOCATE( u_bkg (jpi,jpj,jpk) ) ; u_bkg (:,:,:) = 0._wp
	444	ALLOCATE( v_bkg (jpi,jpj,jpk) ) ; v_bkg (:,:,:) = 0._wp
	445	ALLOCATE( ssh_bkg(jpi,jpj) ) ; ssh_bkg(:,:) = 0._wp
[5836]	446	!
	447	!
[2128]	448	!--------------------------------------------------------------------
	449	! Read from file the background state at analysis time
	450	!--------------------------------------------------------------------
[5836]	451	!
[2128]	452	CALL iom_open( c_asmdin, inum )
[5836]	453	!
[3764]	454	CALL iom_get( inum, 'rdastp', zdate_bkg )
[5836]	455	!
[2128]	456	IF(lwp) THEN
	457	WRITE(numout,*)
[9213]	458	WRITE(numout,*) ' ==>>> Assimilation background state valid at : ', zdate_bkg
	459	WRITE(numout,*)
[2128]	460	ENDIF
[5836]	461	!
[9213]	462	IF ( zdate_bkg /= ditdin_date ) &
[2128]	463	& CALL ctl_warn( ' Validity time of assimilation background state does', &
	464	& ' not agree with Direct Initialization time' )
[5836]	465	!
[2128]	466	IF ( ln_trainc ) THEN
	467	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
	468	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
	469	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
	470	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
	471	ENDIF
[5836]	472	!
[2128]	473	IF ( ln_dyninc ) THEN
	474	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
	475	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
	476	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
	477	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
	478	ENDIF
[5836]	479	!
[2128]	480	IF ( ln_sshinc ) THEN
	481	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
	482	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
	483	ENDIF
[5836]	484	!
[2128]	485	CALL iom_close( inum )
[5836]	486	!
[2128]	487	ENDIF
[2392]	488	!
[12489]	489	IF(lwp) WRITE(numout,*) ' ==>>> Euler time step switch is ', l_1st_euler
[9213]	490	!
	491	IF( lk_asminc ) THEN !== data assimilation ==!
[12377]	492	IF( ln_bkgwri ) CALL asm_bkg_wri( nit000 - 1, Kmm ) ! Output background fields
[9213]	493	IF( ln_asmdin ) THEN ! Direct initialization
[12377]	494	IF( ln_trainc ) CALL tra_asm_inc( nit000 - 1, Kbb, Kmm, ts , Krhs ) ! Tracers
	495	IF( ln_dyninc ) CALL dyn_asm_inc( nit000 - 1, Kbb, Kmm, uu, vv, Krhs ) ! Dynamics
	496	IF( ln_sshinc ) CALL ssh_asm_inc( nit000 - 1, Kbb, Kmm ) ! SSH
[9213]	497	ENDIF
	498	ENDIF
	499	!
[2128]	500	END SUBROUTINE asm_inc_init
[9213]	501
	502
[12377]	503	SUBROUTINE tra_asm_inc( kt, Kbb, Kmm, pts, Krhs )
[2128]	504	!!----------------------------------------------------------------------
	505	!! * ROUTINE tra_asm_inc *
	506	!!
	507	!! ** Purpose : Apply the tracer (T and S) assimilation increments
	508	!!
	509	!! ** Method : Direct initialization or Incremental Analysis Updating
	510	!!
	511	!! ** Action :
	512	!!----------------------------------------------------------------------
[12377]	513	INTEGER , INTENT(in ) :: kt ! Current time step
	514	INTEGER , INTENT(in ) :: Kbb, Kmm, Krhs ! Time level indices
	515	REAL(wp), DIMENSION(jpi,jpj,jpk,jpts,jpt), INTENT(inout) :: pts ! active tracers and RHS of tracer equation
[2392]	516	!
[5836]	517	INTEGER :: ji, jj, jk
	518	INTEGER :: it
[2128]	519	REAL(wp) :: zincwgt ! IAU weight for current time step
[3764]	520	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
[2392]	521	!!----------------------------------------------------------------------
[5836]	522	!
[3764]	523	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
	524	! used to prevent the applied increments taking the temperature below the local freezing point
[4990]	525	DO jk = 1, jpkm1
[12377]	526	CALL eos_fzp( pts(:,:,jk,jp_sal,Kmm), fzptnz(:,:,jk), gdept(:,:,jk,Kmm) )
[4990]	527	END DO
[5836]	528	!
	529	! !--------------------------------------
	530	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	531	! !--------------------------------------
	532	!
[2128]	533	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	534	!
[2128]	535	it = kt - nit000 + 1
[12489]	536	zincwgt = wgtiau(it) / rn_Dt ! IAU weight for the current time step
[5836]	537	!
[2128]	538	IF(lwp) THEN
	539	WRITE(numout,*)
[4990]	540	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
[2128]	541	WRITE(numout,*) '~~~~~~~~~~~~'
	542	ENDIF
[5836]	543	!
[2128]	544	! Update the tracer tendencies
	545	DO jk = 1, jpkm1
[3764]	546	IF (ln_temnofreeze) THEN
	547	! Do not apply negative increments if the temperature will fall below freezing
	548	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
[12377]	549	& pts(:,:,jk,jp_tem,Kmm) + pts(:,:,jk,jp_tem,Krhs) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
	550	pts(:,:,jk,jp_tem,Krhs) = pts(:,:,jk,jp_tem,Krhs) + t_bkginc(:,:,jk) * zincwgt
[3764]	551	END WHERE
	552	ELSE
[12377]	553	pts(:,:,jk,jp_tem,Krhs) = pts(:,:,jk,jp_tem,Krhs) + t_bkginc(:,:,jk) * zincwgt
[3764]	554	ENDIF
	555	IF (ln_salfix) THEN
	556	! Do not apply negative increments if the salinity will fall below a specified
	557	! minimum value salfixmin
	558	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
[12377]	559	& pts(:,:,jk,jp_sal,Kmm) + pts(:,:,jk,jp_sal,Krhs) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
	560	pts(:,:,jk,jp_sal,Krhs) = pts(:,:,jk,jp_sal,Krhs) + s_bkginc(:,:,jk) * zincwgt
[3764]	561	END WHERE
	562	ELSE
[12377]	563	pts(:,:,jk,jp_sal,Krhs) = pts(:,:,jk,jp_sal,Krhs) + s_bkginc(:,:,jk) * zincwgt
[3764]	564	ENDIF
[2128]	565	END DO
[5836]	566	!
[2128]	567	ENDIF
[5836]	568	!
[2128]	569	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
	570	DEALLOCATE( t_bkginc )
	571	DEALLOCATE( s_bkginc )
	572	ENDIF
[5836]	573	! !--------------------------------------
	574	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	575	! !--------------------------------------
	576	!
[2128]	577	IF ( kt == nitdin_r ) THEN
[5836]	578	!
[12489]	579	l_1st_euler = .TRUE. ! Force Euler forward step
[5836]	580	!
[2128]	581	! Initialize the now fields with the background + increment
[3764]	582	IF (ln_temnofreeze) THEN
	583	! Do not apply negative increments if the temperature will fall below freezing
[12377]	584	WHERE( t_bkginc(:,:,:) > 0.0_wp .OR. pts(:,:,:,jp_tem,Kmm) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
	585	pts(:,:,:,jp_tem,Kmm) = t_bkg(:,:,:) + t_bkginc(:,:,:)
[3764]	586	END WHERE
	587	ELSE
[12377]	588	pts(:,:,:,jp_tem,Kmm) = t_bkg(:,:,:) + t_bkginc(:,:,:)
[3764]	589	ENDIF
[2128]	590	IF (ln_salfix) THEN
[3764]	591	! Do not apply negative increments if the salinity will fall below a specified
	592	! minimum value salfixmin
[12377]	593	WHERE( s_bkginc(:,:,:) > 0.0_wp .OR. pts(:,:,:,jp_sal,Kmm) + s_bkginc(:,:,:) > salfixmin )
	594	pts(:,:,:,jp_sal,Kmm) = s_bkg(:,:,:) + s_bkginc(:,:,:)
[3764]	595	END WHERE
	596	ELSE
[12377]	597	pts(:,:,:,jp_sal,Kmm) = s_bkg(:,:,:) + s_bkginc(:,:,:)
[2128]	598	ENDIF
	599
[12377]	600	pts(:,:,:,:,Kbb) = pts(:,:,:,:,Kmm) ! Update before fields
[2128]	601
[12377]	602	CALL eos( pts(:,:,:,:,Kbb), rhd, rhop, gdept_0(:,:,:) ) ! Before potential and in situ densities
[4990]	603	!!gm fabien
[12377]	604	! CALL eos( pts(:,:,:,:,Kbb), rhd, rhop ) ! Before potential and in situ densities
[4990]	605	!!gm
	606
[12377]	607	IF( ln_zps .AND. .NOT. lk_c1d .AND. .NOT. ln_isfcav) &
	608	& CALL zps_hde ( kt, Kmm, jpts, pts(:,:,:,:,Kbb), gtsu, gtsv, & ! Partial steps: before horizontal gradient
	609	& rhd, gru , grv ) ! of t, s, rd at the last ocean level
	610	IF( ln_zps .AND. .NOT. lk_c1d .AND. ln_isfcav) &
	611	& CALL zps_hde_isf( nit000, Kmm, jpts, pts(:,:,:,:,Kbb), gtsu, gtsv, gtui, gtvi, & ! Partial steps for top cell (ISF)
	612	& rhd, gru , grv , grui, grvi ) ! of t, s, rd at the last ocean level
[6140]	613
[2128]	614	DEALLOCATE( t_bkginc )
	615	DEALLOCATE( s_bkginc )
	616	DEALLOCATE( t_bkg )
	617	DEALLOCATE( s_bkg )
	618	ENDIF
[2392]	619	!
[2128]	620	ENDIF
[3764]	621	! Perhaps the following call should be in step
[5836]	622	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
[2392]	623	!
[2128]	624	END SUBROUTINE tra_asm_inc
	625
[2392]	626
[12377]	627	SUBROUTINE dyn_asm_inc( kt, Kbb, Kmm, puu, pvv, Krhs )
[2128]	628	!!----------------------------------------------------------------------
	629	!! * ROUTINE dyn_asm_inc *
	630	!!
	631	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
	632	!!
	633	!! ** Method : Direct initialization or Incremental Analysis Updating.
	634	!!
	635	!! ** Action :
	636	!!----------------------------------------------------------------------
[12377]	637	INTEGER , INTENT( in ) :: kt ! ocean time-step index
	638	INTEGER , INTENT( in ) :: Kbb, Kmm, Krhs ! ocean time level indices
	639	REAL(wp), DIMENSION(jpi,jpj,jpk,jpt), INTENT(inout) :: puu, pvv ! ocean velocities and RHS of momentum equation
[2392]	640	!
[2128]	641	INTEGER :: jk
	642	INTEGER :: it
	643	REAL(wp) :: zincwgt ! IAU weight for current time step
[2392]	644	!!----------------------------------------------------------------------
[5836]	645	!
	646	! !--------------------------------------------
	647	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	648	! !--------------------------------------------
	649	!
[2128]	650	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	651	!
[2128]	652	it = kt - nit000 + 1
[12489]	653	zincwgt = wgtiau(it) / rn_Dt ! IAU weight for the current time step
[5836]	654	!
[2128]	655	IF(lwp) THEN
	656	WRITE(numout,*)
[5836]	657	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
[2128]	658	WRITE(numout,*) '~~~~~~~~~~~~'
	659	ENDIF
[5836]	660	!
[2128]	661	! Update the dynamic tendencies
	662	DO jk = 1, jpkm1
[12377]	663	puu(:,:,jk,Krhs) = puu(:,:,jk,Krhs) + u_bkginc(:,:,jk) * zincwgt
	664	pvv(:,:,jk,Krhs) = pvv(:,:,jk,Krhs) + v_bkginc(:,:,jk) * zincwgt
[2128]	665	END DO
[5836]	666	!
[2128]	667	IF ( kt == nitiaufin_r ) THEN
	668	DEALLOCATE( u_bkginc )
	669	DEALLOCATE( v_bkginc )
	670	ENDIF
[5836]	671	!
[2128]	672	ENDIF
[5836]	673	! !-----------------------------------------
	674	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	675	! !-----------------------------------------
	676	!
[2128]	677	IF ( kt == nitdin_r ) THEN
[5836]	678	!
[12489]	679	l_1st_euler = .TRUE. ! Force Euler forward step
[5836]	680	!
[2128]	681	! Initialize the now fields with the background + increment
[12377]	682	puu(:,:,:,Kmm) = u_bkg(:,:,:) + u_bkginc(:,:,:)
	683	pvv(:,:,:,Kmm) = v_bkg(:,:,:) + v_bkginc(:,:,:)
[5836]	684	!
[12377]	685	puu(:,:,:,Kbb) = puu(:,:,:,Kmm) ! Update before fields
	686	pvv(:,:,:,Kbb) = pvv(:,:,:,Kmm)
[5836]	687	!
[2128]	688	DEALLOCATE( u_bkg )
	689	DEALLOCATE( v_bkg )
	690	DEALLOCATE( u_bkginc )
	691	DEALLOCATE( v_bkginc )
	692	ENDIF
[2392]	693	!
[2128]	694	ENDIF
[2392]	695	!
[2128]	696	END SUBROUTINE dyn_asm_inc
	697
[2392]	698
[12377]	699	SUBROUTINE ssh_asm_inc( kt, Kbb, Kmm )
[2128]	700	!!----------------------------------------------------------------------
	701	!! * ROUTINE ssh_asm_inc *
	702	!!
	703	!! ** Purpose : Apply the sea surface height assimilation increment.
	704	!!
	705	!! ** Method : Direct initialization or Incremental Analysis Updating.
	706	!!
	707	!! ** Action :
	708	!!----------------------------------------------------------------------
[12377]	709	INTEGER, INTENT(IN) :: kt ! Current time step
	710	INTEGER, INTENT(IN) :: Kbb, Kmm ! Current time step
[2392]	711	!
[2128]	712	INTEGER :: it
[3764]	713	INTEGER :: jk
[2128]	714	REAL(wp) :: zincwgt ! IAU weight for current time step
[2392]	715	!!----------------------------------------------------------------------
[5836]	716	!
	717	! !-----------------------------------------
	718	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	719	! !-----------------------------------------
	720	!
[2128]	721	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	722	!
[2128]	723	it = kt - nit000 + 1
[12489]	724	zincwgt = wgtiau(it) / rn_Dt ! IAU weight for the current time step
[5836]	725	!
[2128]	726	IF(lwp) THEN
	727	WRITE(numout,*)
	728	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
	729	& kt,' with IAU weight = ', wgtiau(it)
	730	WRITE(numout,*) '~~~~~~~~~~~~'
	731	ENDIF
[5836]	732	!
[2128]	733	! Save the tendency associated with the IAU weighted SSH increment
	734	! (applied in dynspg.*)
	735	#if defined key_asminc
	736	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
	737	#endif
[5836]	738	!
[8547]	739	ELSE IF( kt == nitiaufin_r+1 ) THEN
[8546]	740	!
[9465]	741	! test on ssh_bkginc needed as ssh_asm_inc is called twice by time step
	742	IF (ALLOCATED(ssh_bkginc)) DEALLOCATE( ssh_bkginc )
	743	!
	744	#if defined key_asminc
[8546]	745	ssh_iau(:,:) = 0._wp
[9465]	746	#endif
[8546]	747	!
[2128]	748	ENDIF
[5836]	749	! !-----------------------------------------
	750	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	751	! !-----------------------------------------
	752	!
[2128]	753	IF ( kt == nitdin_r ) THEN
[5836]	754	!
[12489]	755	l_1st_euler = .TRUE. ! Force Euler forward step
[5836]	756	!
[12377]	757	ssh(:,:,Kmm) = ssh_bkg(:,:) + ssh_bkginc(:,:) ! Initialize the now fields the background + increment
[5836]	758	!
[12377]	759	ssh(:,:,Kbb) = ssh(:,:,Kmm) ! Update before fields
	760	e3t(:,:,:,Kbb) = e3t(:,:,:,Kmm)
	761	!!gm why not e3u(:,:,:,Kbb), e3v(:,:,:,Kbb), gdept(:,:,:,Kbb) ????
[5836]	762	!
[2128]	763	DEALLOCATE( ssh_bkg )
	764	DEALLOCATE( ssh_bkginc )
[5836]	765	!
[2128]	766	ENDIF
[2392]	767	!
[2128]	768	ENDIF
[2392]	769	!
[2128]	770	END SUBROUTINE ssh_asm_inc
	771
[9213]	772
[12377]	773	SUBROUTINE ssh_asm_div( kt, Kbb, Kmm, phdivn )
[9023]	774	!!----------------------------------------------------------------------
	775	!! * ROUTINE ssh_asm_div *
	776	!!
	777	!! ** Purpose : ssh increment with z* is incorporated via a correction of the local divergence
	778	!! across all the water column
	779	!!
	780	!! ** Method :
	781	!! CAUTION : sshiau is positive (inflow) decreasing the
	782	!! divergence and expressed in m/s
	783	!!
	784	!! ** Action : phdivn decreased by the ssh increment
	785	!!----------------------------------------------------------------------
	786	INTEGER, INTENT(IN) :: kt ! ocean time-step index
[12377]	787	INTEGER, INTENT(IN) :: Kbb, Kmm ! time level indices
[9023]	788	REAL(wp), DIMENSION(:,:,:), INTENT(inout) :: phdivn ! horizontal divergence
	789	!!
	790	INTEGER :: jk ! dummy loop index
	791	REAL(wp), DIMENSION(:,:) , POINTER :: ztim ! local array
	792	!!----------------------------------------------------------------------
	793	!
	794	#if defined key_asminc
[12377]	795	CALL ssh_asm_inc( kt, Kbb, Kmm ) !== (calculate increments)
[9023]	796	!
	797	IF( ln_linssh ) THEN
[12377]	798	phdivn(:,:,1) = phdivn(:,:,1) - ssh_iau(:,:) / e3t(:,:,1,Kmm) * tmask(:,:,1)
[9023]	799	ELSE
[9044]	800	ALLOCATE( ztim(jpi,jpj) )
[12377]	801	ztim(:,:) = ssh_iau(:,:) / ( ht(:,:) + 1.0 - ssmask(:,:) )
[9023]	802	DO jk = 1, jpkm1
	803	phdivn(:,:,jk) = phdivn(:,:,jk) - ztim(:,:) * tmask(:,:,jk)
	804	END DO
	805	!
[9044]	806	DEALLOCATE(ztim)
[9023]	807	ENDIF
	808	#endif
	809	!
	810	END SUBROUTINE ssh_asm_div
[3785]	811
[9213]	812
[3764]	813	SUBROUTINE seaice_asm_inc( kt, kindic )
	814	!!----------------------------------------------------------------------
	815	!! * ROUTINE seaice_asm_inc *
	816	!!
	817	!! ** Purpose : Apply the sea ice assimilation increment.
	818	!!
	819	!! ** Method : Direct initialization or Incremental Analysis Updating.
	820	!!
	821	!! ** Action :
	822	!!
	823	!!----------------------------------------------------------------------
[5836]	824	INTEGER, INTENT(in) :: kt ! Current time step
[3785]	825	INTEGER, INTENT(in), OPTIONAL :: kindic ! flag for disabling the deallocation
	826	!
	827	INTEGER :: it
	828	REAL(wp) :: zincwgt ! IAU weight for current time step
[9570]	829	#if defined key_si3
[9656]	830	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc
[3785]	831	REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
[3764]	832	#endif
[3785]	833	!!----------------------------------------------------------------------
[5836]	834	!
	835	! !-----------------------------------------
	836	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
	837	! !-----------------------------------------
	838	!
[3764]	839	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
[5836]	840	!
[3764]	841	it = kt - nit000 + 1
	842	zincwgt = wgtiau(it) ! IAU weight for the current time step
[12489]	843	! note this is not a tendency so should not be divided by rn_Dt (as with the tracer and other increments)
[5836]	844	!
[3764]	845	IF(lwp) THEN
	846	WRITE(numout,*)
[5836]	847	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
[3764]	848	WRITE(numout,*) '~~~~~~~~~~~~'
	849	ENDIF
[5836]	850	!
[9656]	851	! Sea-ice : SI3 case
[5836]	852	!
[9570]	853	#if defined key_si3
[9019]	854	zofrld (:,:) = 1._wp - at_i(:,:)
	855	zohicif(:,:) = hm_i(:,:)
[3785]	856	!
[9019]	857	at_i (:,:) = 1. - MIN( MAX( 1.-at_i (:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
	858	at_i_b(:,:) = 1. - MIN( MAX( 1.-at_i_b(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
	859	fr_i(:,:) = at_i(:,:) ! adjust ice fraction
[3785]	860	!
[9019]	861	zseaicendg(:,:) = zofrld(:,:) - (1. - at_i(:,:)) ! find out actual sea ice nudge applied
[3785]	862	!
[3764]	863	! Nudge sea ice depth to bring it up to a required minimum depth
[9019]	864	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hm_i(:,:) < zhicifmin )
	865	zhicifinc(:,:) = (zhicifmin - hm_i(:,:)) * zincwgt
[3764]	866	ELSEWHERE
	867	zhicifinc(:,:) = 0.0_wp
	868	END WHERE
[3785]	869	!
	870	! nudge ice depth
[9019]	871	hm_i (:,:) = hm_i (:,:) + zhicifinc(:,:)
[3785]	872	!
	873	! seaice salinity balancing (to add)
[3764]	874	#endif
[9213]	875	!
[4245]	876	#if defined key_cice && defined key_asminc
[3785]	877	! Sea-ice : CICE case. Pass ice increment tendency into CICE
[12489]	878	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rn_Dt
[3764]	879	#endif
[9213]	880	!
[3764]	881	IF ( kt == nitiaufin_r ) THEN
	882	DEALLOCATE( seaice_bkginc )
	883	ENDIF
[9213]	884	!
[3764]	885	ELSE
[9213]	886	!
[4245]	887	#if defined key_cice && defined key_asminc
[5836]	888	ndaice_da(:,:) = 0._wp ! Sea-ice : CICE case. Zero ice increment tendency into CICE
[3764]	889	#endif
[9213]	890	!
[3764]	891	ENDIF
[5836]	892	! !-----------------------------------------
	893	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
	894	! !-----------------------------------------
	895	!
[3764]	896	IF ( kt == nitdin_r ) THEN
[5836]	897	!
[12713]	898	l_1st_euler = .TRUE. ! Force Euler forward step
[5836]	899	!
[9656]	900	! Sea-ice : SI3 case
[5836]	901	!
[9570]	902	#if defined key_si3
[9019]	903	zofrld (:,:) = 1._wp - at_i(:,:)
	904	zohicif(:,:) = hm_i(:,:)
[3785]	905	!
[3764]	906	! Initialize the now fields the background + increment
[9019]	907	at_i(:,:) = 1. - MIN( MAX( 1.-at_i(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
	908	at_i_b(:,:) = at_i(:,:)
	909	fr_i(:,:) = at_i(:,:) ! adjust ice fraction
[3785]	910	!
[9019]	911	zseaicendg(:,:) = zofrld(:,:) - (1. - at_i(:,:)) ! find out actual sea ice nudge applied
	912	!
[3764]	913	! Nudge sea ice depth to bring it up to a required minimum depth
[9019]	914	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hm_i(:,:) < zhicifmin )
[10355]	915	zhicifinc(:,:) = zhicifmin - hm_i(:,:)
[3764]	916	ELSEWHERE
[9019]	917	zhicifinc(:,:) = 0.0_wp
[3764]	918	END WHERE
[3785]	919	!
	920	! nudge ice depth
[9019]	921	hm_i (:,:) = hm_i (:,:) + zhicifinc(:,:)
[3785]	922	!
	923	! seaice salinity balancing (to add)
[3764]	924	#endif
[5836]	925	!
[4245]	926	#if defined key_cice && defined key_asminc
	927	! Sea-ice : CICE case. Pass ice increment tendency into CICE
[12489]	928	ndaice_da(:,:) = seaice_bkginc(:,:) / rn_Dt
[3764]	929	#endif
[5836]	930	IF ( .NOT. PRESENT(kindic) ) THEN
	931	DEALLOCATE( seaice_bkginc )
	932	END IF
	933	!
[3764]	934	ELSE
[5836]	935	!
	936	#if defined key_cice && defined key_asminc
	937	ndaice_da(:,:) = 0._wp ! Sea-ice : CICE case. Zero ice increment tendency into CICE
[3764]	938	#endif
[5836]	939	!
[3764]	940	ENDIF
	941
[9570]	942	!#if defined defined key_si3 \|\| defined key_cice
[3764]	943	!
	944	! IF (ln_seaicebal ) THEN
	945	! !! balancing salinity increments
	946	! !! simple case from limflx.F90 (doesn't include a mass flux)
	947	! !! assumption is that as ice concentration is reduced or increased
	948	! !! the snow and ice depths remain constant
	949	! !! note that snow is being created where ice concentration is being increased
	950	! !! - could be more sophisticated and
	951	! !! not do this (but would need to alter h_snow)
	952	!
	953	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
	954	!
	955	! DO jj = 1, jpj
	956	! DO ji = 1, jpi
	957	! ! calculate change in ice and snow mass per unit area
	958	! ! positive values imply adding salt to the ocean (results from ice formation)
	959	! ! fwf : ice formation and melting
	960	!
[12489]	961	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rn_Dt
[3764]	962	!
	963	! ! change salinity down to mixed layer depth
	964	! mld=hmld_kara(ji,jj)
	965	!
	966	! ! prevent small mld
	967	! ! less than 10m can cause salinity instability
	968	! IF (mld < 10) mld=10
	969	!
	970	! ! set to bottom of a level
	971	! DO jk = jpk-1, 2, -1
	972	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
	973	! mld=gdepw(ji,jj,jk+1)
	974	! jkmax=jk
	975	! ENDIF
	976	! ENDDO
	977	!
	978	! ! avoid applying salinity balancing in shallow water or on land
	979	! !
	980	!
	981	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
	982	!
	983	! dsal_ocn=0.0_wp
	984	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
	985	!
	986	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
	987	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
	988	!
	989	! ! put increments in for levels in the mixed layer
	990	! ! but prevent salinity below a threshold value
	991	!
	992	! DO jk = 1, jkmax
	993	!
	994	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
	995	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
	996	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
	997	! ENDIF
	998	!
	999	! ENDDO
	1000	!
	1001	! ! ! salt exchanges at the ice/ocean interface
[12489]	1002	! ! zpmess = zfons / rDt_ice ! rDt_ice is ice timestep
[3764]	1003	! !
	1004	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
	1005	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
	1006	! !!
	1007	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
	1008	! !! ! E-P (kg m-2 s-2)
	1009	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
	1010	! ENDDO !ji
	1011	! ENDDO !jj!
	1012	!
	1013	! ENDIF !ln_seaicebal
	1014	!
	1015	!#endif
[5836]	1016	!
[3764]	1017	ENDIF
[5836]	1018	!
[3764]	1019	END SUBROUTINE seaice_asm_inc
[3785]	1020
[2392]	1021	!!======================================================================
[2128]	1022	END MODULE asminc

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