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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

Line
1	MODULE asminc
2	!!======================================================================
3	!! * MODULE asminc *
4	!! Assimilation increment : Apply an increment generated by data
5	!! assimilation
6	!!======================================================================
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
12	!! 3.4 ! 2012-10 (A. Weaver and K. Mogensen) Fix for direct initialization
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
15	!!----------------------------------------------------------------------
16
17	!!----------------------------------------------------------------------
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
22	!! ssh_asm_div : Apply divergence associated with SSH increment
23	!! seaice_asm_inc : Apply the seaice increment
24	!!----------------------------------------------------------------------
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
38	#endif
39	!
40	USE in_out_manager ! I/O manager
41	USE iom ! Library to read input files
42	USE lib_mpp ! MPP library
43
44	IMPLICIT NONE
45	PRIVATE
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
51	PUBLIC ssh_asm_div !: Apply the SSH divergence
52	PUBLIC seaice_asm_inc !: Apply the seaice increment
53
54	#if defined key_asminc
55	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
56	#else
57	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
58	#endif
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
67	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
68	INTEGER, PUBLIC :: nn_divdmp !: Apply divergence damping filter nn_divdmp times
69
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
75	#if defined key_asminc
76	REAL(wp), PUBLIC, DIMENSION(:,:) , ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
77	#endif
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)
87
88	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
89	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
90	#if defined key_cice && defined key_asminc
91	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ndaice_da ! ice increment tendency into CICE
92	#endif
93
94	!! * Substitutions
95	# include "vectopt_loop_substitute.h90"
96	!!----------------------------------------------------------------------
97	!! NEMO/OPA 3.7 , NEMO Consortium (2015)
98	!! $Id$
99	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
100	!!----------------------------------------------------------------------
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	!!----------------------------------------------------------------------
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
116	INTEGER :: iiauper ! Number of time steps in the IAU period
117	INTEGER :: icycper ! Number of time steps in the cycle
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
124	REAL(wp) :: znorm ! Normalization factor for IAU weights
125	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights (should be equal to one)
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
130	!
131	REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: zhdiv ! 2D workspace
132	!!
133	NAMELIST/nam_asminc/ ln_bkgwri, &
134	& ln_trainc, ln_dyninc, ln_sshinc, &
135	& ln_asmdin, ln_asmiau, &
136	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
137	& ln_salfix, salfixmin, nn_divdmp
138	!!----------------------------------------------------------------------
139
140	!-----------------------------------------------------------------------
141	! Read Namelist nam_asminc : assimilation increment interface
142	!-----------------------------------------------------------------------
143	ln_seaiceinc = .FALSE.
144	ln_temnofreeze = .FALSE.
145
146	REWIND( numnam_ref ) ! Namelist nam_asminc in reference namelist : Assimilation increment
147	READ ( numnam_ref, nam_asminc, IOSTAT = ios, ERR = 901)
148	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in reference namelist', lwp )
149	REWIND( numnam_cfg ) ! Namelist nam_asminc in configuration namelist : Assimilation increment
150	READ ( numnam_cfg, nam_asminc, IOSTAT = ios, ERR = 902 )
151	902 IF( ios > 0 ) CALL ctl_nam ( ios , 'nam_asminc in configuration namelist', lwp )
152	IF(lwm) WRITE ( numond, nam_asminc )
153
154	! Control print
155	IF(lwp) THEN
156	WRITE(numout,*)
157	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
158	WRITE(numout,*) '~~~~~~~~~~~~'
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
165	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
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
174	ENDIF
175
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
180
181	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
182	icycper = nitend - nit000 + 1 ! Cycle interval length
183
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
189
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
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
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 ) ) &
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.', &
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
227	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ).AND.( .NOT. ln_seaiceinc ) &
228	& ) &
229	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc are set to .false. :', &
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
256	IF( ln_asmiau ) THEN
257	!
258	ALLOCATE( wgtiau( icycper ) )
259	!
260	wgtiau(:) = 0._wp
261	!
262	! !---------------------------------------------------------
263	IF( niaufn == 0 ) THEN ! Constant IAU forcing
264	! !---------------------------------------------------------
265	DO jt = 1, iiauper
266	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
267	END DO
268	! !---------------------------------------------------------
269	ELSEIF ( niaufn == 1 ) THEN ! Linear hat-like, centred in middle of IAU interval
270	! !---------------------------------------------------------
271	! Compute the normalization factor
272	znorm = 0._wp
273	IF( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
274	imid = iiauper / 2
275	DO jt = 1, imid
276	znorm = znorm + REAL( jt )
277	END DO
278	znorm = 2.0 * znorm
279	ELSE ! Odd number of time steps in IAU interval
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
287	!
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
294	!
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
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
326	#if defined key_asminc
327	ALLOCATE( ssh_iau (jpi,jpj) ) ; ssh_iau (:,:) = 0._wp
328	#endif
329	#if defined key_cice && defined key_asminc
330	ALLOCATE( ndaice_da (jpi,jpj) ) ; ndaice_da (:,:) = 0._wp
331	#endif
332	!
333	IF ( ln_trainc .OR. ln_dyninc .OR. & !--------------------------------------
334	& ln_sshinc .OR. ln_seaiceinc ) THEN ! Read the increments from file
335	! !--------------------------------------
336	CALL iom_open( c_asminc, inum )
337	!
338	CALL iom_get( inum, 'time' , zdate_inc )
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
343	!
344	IF(lwp) THEN
345	WRITE(numout,*)
346	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid between dates ', z_inc_dateb,' and ', z_inc_datef
347	WRITE(numout,*) '~~~~~~~~~~~~'
348	ENDIF
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' )
354
355	IF ( ( ln_asmdin ).AND.( zdate_inc /= ditdin_date ) ) &
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
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
400	!
401	CALL iom_close( inum )
402	!
403	ENDIF
404	!
405	! !--------------------------------------
406	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN ! Apply divergence damping filter
407	! !--------------------------------------
408	ALLOCATE( zhdiv(jpi,jpj) )
409	!
410	DO jt = 1, nn_divdmp
411	!
412	DO jk = 1, jpkm1 ! zhdiv = e1e1 * div
413	zhdiv(:,:) = 0._wp
414	DO jj = 2, jpjm1
415	DO ji = fs_2, fs_jpim1 ! vector opt.
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)
420	END DO
421	END DO
422	CALL lbc_lnk( zhdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
423	!
424	DO jj = 2, jpjm1
425	DO ji = fs_2, fs_jpim1 ! vector opt.
426	u_bkginc(ji,jj,jk) = u_bkginc(ji,jj,jk) &
427	& + 0.2_wp * ( zhdiv(ji+1,jj) - zhdiv(ji ,jj) ) * r1_e1u(ji,jj) * umask(ji,jj,jk)
428	v_bkginc(ji,jj,jk) = v_bkginc(ji,jj,jk) &
429	& + 0.2_wp * ( zhdiv(ji,jj+1) - zhdiv(ji,jj ) ) * r1_e2v(ji,jj) * vmask(ji,jj,jk)
430	END DO
431	END DO
432	END DO
433	!
434	END DO
435	!
436	DEALLOCATE( zhdiv )
437	!
438	ENDIF
439	!
440	! !-----------------------------------------------------
441	IF ( ln_asmdin ) THEN ! Allocate and initialize the background state arrays
442	! !-----------------------------------------------------
443	!
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
449	!
450	!
451	!--------------------------------------------------------------------
452	! Read from file the background state at analysis time
453	!--------------------------------------------------------------------
454	!
455	CALL iom_open( c_asmdin, inum )
456	!
457	CALL iom_get( inum, 'rdastp', zdate_bkg )
458	!
459	IF(lwp) THEN
460	WRITE(numout,*)
461	WRITE(numout,*) ' ==>>> Assimilation background state valid at : ', zdate_bkg
462	WRITE(numout,*)
463	ENDIF
464	!
465	IF ( zdate_bkg /= ditdin_date ) &
466	& CALL ctl_warn( ' Validity time of assimilation background state does', &
467	& ' not agree with Direct Initialization time' )
468	!
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
475	!
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
482	!
483	IF ( ln_sshinc ) THEN
484	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
485	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
486	ENDIF
487	!
488	CALL iom_close( inum )
489	!
490	ENDIF
491	!
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	!
503	END SUBROUTINE asm_inc_init
504
505
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	!!----------------------------------------------------------------------
516	INTEGER, INTENT(IN) :: kt ! Current time step
517	!
518	INTEGER :: ji, jj, jk
519	INTEGER :: it
520	REAL(wp) :: zincwgt ! IAU weight for current time step
521	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
522	!!----------------------------------------------------------------------
523	!
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
526	DO jk = 1, jpkm1
527	CALL eos_fzp( tsn(:,:,jk,jp_sal), fzptnz(:,:,jk), gdept_n(:,:,jk) )
528	END DO
529	!
530	! !--------------------------------------
531	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
532	! !--------------------------------------
533	!
534	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
535	!
536	it = kt - nit000 + 1
537	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
538	!
539	IF(lwp) THEN
540	WRITE(numout,*)
541	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
542	WRITE(numout,*) '~~~~~~~~~~~~'
543	ENDIF
544	!
545	! Update the tracer tendencies
546	DO jk = 1, jpkm1
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
566	END DO
567	!
568	ENDIF
569	!
570	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
571	DEALLOCATE( t_bkginc )
572	DEALLOCATE( s_bkginc )
573	ENDIF
574	! !--------------------------------------
575	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
576	! !--------------------------------------
577	!
578	IF ( kt == nitdin_r ) THEN
579	!
580	neuler = 0 ! Force Euler forward step
581	!
582	! Initialize the now fields with the background + increment
583	IF (ln_temnofreeze) THEN
584	! Do not apply negative increments if the temperature will fall below freezing
585	WHERE( t_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
586	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
587	END WHERE
588	ELSE
589	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
590	ENDIF
591	IF (ln_salfix) THEN
592	! Do not apply negative increments if the salinity will fall below a specified
593	! minimum value salfixmin
594	WHERE( s_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
595	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
596	END WHERE
597	ELSE
598	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
599	ENDIF
600
601	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
602
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
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
615	DEALLOCATE( t_bkginc )
616	DEALLOCATE( s_bkginc )
617	DEALLOCATE( t_bkg )
618	DEALLOCATE( s_bkg )
619	ENDIF
620	!
621	ENDIF
622	! Perhaps the following call should be in step
623	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
624	!
625	END SUBROUTINE tra_asm_inc
626
627
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
639	!
640	INTEGER :: jk
641	INTEGER :: it
642	REAL(wp) :: zincwgt ! IAU weight for current time step
643	!!----------------------------------------------------------------------
644	!
645	! !--------------------------------------------
646	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
647	! !--------------------------------------------
648	!
649	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
650	!
651	it = kt - nit000 + 1
652	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
653	!
654	IF(lwp) THEN
655	WRITE(numout,*)
656	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
657	WRITE(numout,*) '~~~~~~~~~~~~'
658	ENDIF
659	!
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
665	!
666	IF ( kt == nitiaufin_r ) THEN
667	DEALLOCATE( u_bkginc )
668	DEALLOCATE( v_bkginc )
669	ENDIF
670	!
671	ENDIF
672	! !-----------------------------------------
673	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
674	! !-----------------------------------------
675	!
676	IF ( kt == nitdin_r ) THEN
677	!
678	neuler = 0 ! Force Euler forward step
679	!
680	! Initialize the now fields with the background + increment
681	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
682	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
683	!
684	ub(:,:,:) = un(:,:,:) ! Update before fields
685	vb(:,:,:) = vn(:,:,:)
686	!
687	DEALLOCATE( u_bkg )
688	DEALLOCATE( v_bkg )
689	DEALLOCATE( u_bkginc )
690	DEALLOCATE( v_bkginc )
691	ENDIF
692	!
693	ENDIF
694	!
695	END SUBROUTINE dyn_asm_inc
696
697
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
709	!
710	INTEGER :: it
711	INTEGER :: jk
712	REAL(wp) :: zincwgt ! IAU weight for current time step
713	!!----------------------------------------------------------------------
714	!
715	! !-----------------------------------------
716	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
717	! !-----------------------------------------
718	!
719	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
720	!
721	it = kt - nit000 + 1
722	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
723	!
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
730	!
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
739	!
740	#if defined key_asminc
741	ELSE IF( kt == nitiaufin_r+1 ) THEN
742	!
743	ssh_iau(:,:) = 0._wp
744	!
745	#endif
746	ENDIF
747	! !-----------------------------------------
748	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
749	! !-----------------------------------------
750	!
751	IF ( kt == nitdin_r ) THEN
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
758	e3t_b(:,:,:) = e3t_n(:,:,:)
759	!!gm why not e3u_b, e3v_b, gdept_b ????
760	!
761	DEALLOCATE( ssh_bkg )
762	DEALLOCATE( ssh_bkginc )
763	!
764	ENDIF
765	!
766	ENDIF
767	!
768	END SUBROUTINE ssh_asm_inc
769
770
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
797	ALLOCATE( ztim(jpi,jpj) )
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	!
803	DEALLOCATE(ztim)
804	ENDIF
805	#endif
806	!
807	END SUBROUTINE ssh_asm_div
808
809
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	!!----------------------------------------------------------------------
821	INTEGER, INTENT(in) :: kt ! Current time step
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
826	#if defined key_lim3
827	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
828	REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
829	#endif
830	!!----------------------------------------------------------------------
831	!
832	! !-----------------------------------------
833	IF ( ln_asmiau ) THEN ! Incremental Analysis Updating
834	! !-----------------------------------------
835	!
836	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
837	!
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)
841	!
842	IF(lwp) THEN
843	WRITE(numout,*)
844	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
845	WRITE(numout,*) '~~~~~~~~~~~~'
846	ENDIF
847	!
848	! Sea-ice : LIM-3 case
849	!
850	#if defined key_lim3
851	zofrld (:,:) = 1._wp - at_i(:,:)
852	zohicif(:,:) = hm_i(:,:)
853	!
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
857	!
858	zseaicendg(:,:) = zofrld(:,:) - (1. - at_i(:,:)) ! find out actual sea ice nudge applied
859	!
860	! Nudge sea ice depth to bring it up to a required minimum depth
861	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hm_i(:,:) < zhicifmin )
862	zhicifinc(:,:) = (zhicifmin - hm_i(:,:)) * zincwgt
863	ELSEWHERE
864	zhicifinc(:,:) = 0.0_wp
865	END WHERE
866	!
867	! nudge ice depth
868	hm_i (:,:) = hm_i (:,:) + zhicifinc(:,:)
869	!
870	! seaice salinity balancing (to add)
871	#endif
872	!
873	#if defined key_cice && defined key_asminc
874	! Sea-ice : CICE case. Pass ice increment tendency into CICE
875	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
876	#endif
877	!
878	IF ( kt == nitiaufin_r ) THEN
879	DEALLOCATE( seaice_bkginc )
880	ENDIF
881	!
882	ELSE
883	!
884	#if defined key_cice && defined key_asminc
885	ndaice_da(:,:) = 0._wp ! Sea-ice : CICE case. Zero ice increment tendency into CICE
886	#endif
887	!
888	ENDIF
889	! !-----------------------------------------
890	ELSEIF ( ln_asmdin ) THEN ! Direct Initialization
891	! !-----------------------------------------
892	!
893	IF ( kt == nitdin_r ) THEN
894	!
895	neuler = 0 ! Force Euler forward step
896	!
897	! Sea-ice : LIM-3 case
898	!
899	#if defined key_lim3
900	zofrld (:,:) = 1._wp - at_i(:,:)
901	zohicif(:,:) = hm_i(:,:)
902	!
903	! Initialize the now fields the background + increment
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
907	!
908	zseaicendg(:,:) = zofrld(:,:) - (1. - at_i(:,:)) ! find out actual sea ice nudge applied
909	!
910	! Nudge sea ice depth to bring it up to a required minimum depth
911	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hm_i(:,:) < zhicifmin )
912	zhicifinc(:,:) = (zhicifmin - hm_i(:,:)) * zincwgt
913	ELSEWHERE
914	zhicifinc(:,:) = 0.0_wp
915	END WHERE
916	!
917	! nudge ice depth
918	hm_i (:,:) = hm_i (:,:) + zhicifinc(:,:)
919	!
920	! seaice salinity balancing (to add)
921	#endif
922	!
923	#if defined key_cice && defined key_asminc
924	! Sea-ice : CICE case. Pass ice increment tendency into CICE
925	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
926	#endif
927	IF ( .NOT. PRESENT(kindic) ) THEN
928	DEALLOCATE( seaice_bkginc )
929	END IF
930	!
931	ELSE
932	!
933	#if defined key_cice && defined key_asminc
934	ndaice_da(:,:) = 0._wp ! Sea-ice : CICE case. Zero ice increment tendency into CICE
935	#endif
936	!
937	ENDIF
938
939	!#if defined defined key_lim3 \|\| defined key_cice
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
1013	!
1014	ENDIF
1015	!
1016	END SUBROUTINE seaice_asm_inc
1017
1018	!!======================================================================
1019	END MODULE asminc

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