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asminc.F90 in branches/UKMO/dev_r5518_GO6_package_inc_asm/NEMOGCM/NEMO/OPA_SRC/ASM – NEMO

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source: branches/UKMO/dev_r5518_GO6_package_inc_asm/NEMOGCM/NEMO/OPA_SRC/ASM/asminc.F90 @ 7955

Last change on this file since 7955 was 7955, checked in by jwhile, 8 years ago
Minor bug fix
File size: 48.9 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	!!----------------------------------------------------------------------
14
15	!!----------------------------------------------------------------------
16	!! 'key_asminc' : Switch on the assimilation increment interface
17	!!----------------------------------------------------------------------
18	!! asm_inc_init : Initialize the increment arrays and IAU weights
19	!! calc_date : Compute the calendar date YYYYMMDD on a given step
20	!! tra_asm_inc : Apply the tracer (T and S) increments
21	!! dyn_asm_inc : Apply the dynamic (u and v) increments
22	!! ssh_asm_inc : Apply the SSH increment
23	!! seaice_asm_inc : Apply the seaice increment
24	!!----------------------------------------------------------------------
25	USE wrk_nemo ! Memory Allocation
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 oce ! Dynamics and active tracers defined in memory
30	USE ldfdyn_oce ! ocean dynamics: lateral physics
31	USE eosbn2 ! Equation of state - in situ and potential density
32	USE zpshde ! Partial step : Horizontal Derivative
33	USE iom ! Library to read input files
34	USE asmpar ! Parameters for the assmilation interface
35	USE c1d ! 1D initialization
36	USE in_out_manager ! I/O manager
37	USE lib_mpp ! MPP library
38	#if defined key_lim2
39	USE ice_2 ! LIM2
40	#endif
41	#if defined key_cice && defined key_asminc
42	USE sbc_ice ! Surface boundary condition for ice.
43	#endif
44	USE sbc_oce ! Surface boundary condition variables.
45
46	IMPLICIT NONE
47	PRIVATE
48
49	PUBLIC asm_inc_init !: Initialize the increment arrays and IAU weights
50	PUBLIC calc_date !: Compute the calendar date YYYYMMDD on a given step
51	PUBLIC tra_asm_inc !: Apply the tracer (T and S) increments
52	PUBLIC dyn_asm_inc !: Apply the dynamic (u and v) increments
53	PUBLIC ssh_asm_inc !: Apply the SSH increment
54	PUBLIC seaice_asm_inc !: Apply the seaice increment
55
56	#if defined key_asminc
57	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
58	#else
59	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
60	#endif
61	LOGICAL, PUBLIC :: ln_bkgwri = .FALSE. !: No output of the background state fields
62	LOGICAL, PUBLIC :: ln_asmiau = .FALSE. !: No applying forcing with an assimilation increment
63	LOGICAL, PUBLIC :: ln_asmdin = .FALSE. !: No direct initialization
64	LOGICAL, PUBLIC :: ln_trainc = .FALSE. !: No tracer (T and S) assimilation increments
65	LOGICAL, PUBLIC :: ln_dyninc = .FALSE. !: No dynamics (u and v) assimilation increments
66	LOGICAL, PUBLIC :: ln_sshinc = .FALSE. !: No sea surface height assimilation increment
67	LOGICAL, PUBLIC :: ln_seaiceinc !: No sea ice concentration increment
68	LOGICAL, PUBLIC :: ln_salfix = .FALSE. !: Apply minimum salinity check
69	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
70	INTEGER, PUBLIC :: nn_divdmp !: Apply divergence damping filter nn_divdmp times
71
72	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkg , s_bkg !: Background temperature and salinity
73	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkg , v_bkg !: Background u- & v- velocity components
74	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkginc, s_bkginc !: Increment to the background T & S
75	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkginc, v_bkginc !: Increment to the u- & v-components
76	REAL(wp), PUBLIC, DIMENSION(:) , ALLOCATABLE :: wgtiau !: IAU weights for each time step
77	#if defined key_asminc
78	REAL(wp), PUBLIC, DIMENSION(:,:), ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
79	#endif
80	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
81	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
82	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
83	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
84	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
85	!
86	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
87	! !: = 1 Linear hat-like, centred in middle of IAU interval
88	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
89
90	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
91	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
92
93	!! * Substitutions
94	# include "domzgr_substitute.h90"
95	# include "ldfdyn_substitute.h90"
96	# include "vectopt_loop_substitute.h90"
97	!!----------------------------------------------------------------------
98	!! NEMO/OPA 3.3 , NEMO Consortium (2010)
99	!! $Id$
100	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
101	!!----------------------------------------------------------------------
102	CONTAINS
103
104	SUBROUTINE asm_inc_init
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	!!----------------------------------------------------------------------
114	INTEGER :: ji, jj, jk, jt ! dummy loop indices
115	INTEGER :: imid, inum ! local integers
116	INTEGER :: ios ! Local integer output status for namelist read
117	INTEGER :: iiauper ! Number of time steps in the IAU period
118	INTEGER :: icycper ! Number of time steps in the cycle
119	INTEGER :: iitend_date ! Date YYYYMMDD of final time step
120	INTEGER :: iitbkg_date ! Date YYYYMMDD of background time step for Jb term
121	INTEGER :: iitdin_date ! Date YYYYMMDD of background time step for DI
122	INTEGER :: iitiaustr_date ! Date YYYYMMDD of IAU interval start time step
123	INTEGER :: iitiaufin_date ! Date YYYYMMDD of IAU interval final time step
124	!
125	REAL(wp) :: znorm ! Normalization factor for IAU weights
126	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights (should be equal to one)
127	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
128	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
129	REAL(wp) :: zdate_bkg ! Date in background state file for DI
130	REAL(wp) :: zdate_inc ! Time axis in increments file
131	!
132	REAL(wp), POINTER, DIMENSION(:,:) :: hdiv ! 2D workspace
133	!!
134	NAMELIST/nam_asminc/ ln_bkgwri, &
135	& ln_trainc, ln_dyninc, ln_sshinc, &
136	& ln_asmdin, ln_asmiau, &
137	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
138	& ln_salfix, salfixmin, nn_divdmp
139	!!----------------------------------------------------------------------
140
141	!-----------------------------------------------------------------------
142	! Read Namelist nam_asminc : assimilation increment interface
143	!-----------------------------------------------------------------------
144	ln_seaiceinc = .FALSE.
145	ln_temnofreeze = .FALSE.
146
147	REWIND( numnam_ref ) ! Namelist nam_asminc in reference namelist : Assimilation increment
148	READ ( numnam_ref, nam_asminc, IOSTAT = ios, ERR = 901)
149	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in reference namelist', lwp )
150
151	REWIND( numnam_cfg ) ! Namelist nam_asminc in configuration namelist : Assimilation increment
152	READ ( numnam_cfg, nam_asminc, IOSTAT = ios, ERR = 902 )
153	902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in configuration namelist', lwp )
154	IF(lwm) WRITE ( numond, nam_asminc )
155
156	! Control print
157	IF(lwp) THEN
158	WRITE(numout,*)
159	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
160	WRITE(numout,*) '~~~~~~~~~~~~'
161	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
162	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
163	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
164	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
165	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
166	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
167	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
168	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
169	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
170	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
171	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
172	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
173	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
174	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
175	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
176	ENDIF
177
178	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
179	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
180	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
181	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
182
183	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
184	icycper = nitend - nit000 + 1 ! Cycle interval length
185
186	CALL calc_date( nit000, nitend , ndate0, iitend_date ) ! Date of final time step
187	CALL calc_date( nit000, nitbkg_r , ndate0, iitbkg_date ) ! Background time for Jb referenced to ndate0
188	CALL calc_date( nit000, nitdin_r , ndate0, iitdin_date ) ! Background time for DI referenced to ndate0
189	CALL calc_date( nit000, nitiaustr_r, ndate0, iitiaustr_date ) ! IAU start time referenced to ndate0
190	CALL calc_date( nit000, nitiaufin_r, ndate0, iitiaufin_date ) ! IAU end time referenced to ndate0
191	!
192	IF(lwp) THEN
193	WRITE(numout,*)
194	WRITE(numout,*) ' Time steps referenced to current cycle:'
195	WRITE(numout,*) ' iitrst = ', nit000 - 1
196	WRITE(numout,*) ' nit000 = ', nit000
197	WRITE(numout,*) ' nitend = ', nitend
198	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
199	WRITE(numout,*) ' nitdin_r = ', nitdin_r
200	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
201	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
202	WRITE(numout,*)
203	WRITE(numout,*) ' Dates referenced to current cycle:'
204	WRITE(numout,*) ' ndastp = ', ndastp
205	WRITE(numout,*) ' ndate0 = ', ndate0
206	WRITE(numout,*) ' iitend_date = ', iitend_date
207	WRITE(numout,*) ' iitbkg_date = ', iitbkg_date
208	WRITE(numout,*) ' iitdin_date = ', iitdin_date
209	WRITE(numout,*) ' iitiaustr_date = ', iitiaustr_date
210	WRITE(numout,*) ' iitiaufin_date = ', iitiaufin_date
211	ENDIF
212
213	IF ( nacc /= 0 ) &
214	& CALL ctl_stop( ' nacc /= 0 and key_asminc :', &
215	& ' Assimilation increments have only been implemented', &
216	& ' for synchronous time stepping' )
217
218	IF ( ( ln_asmdin ).AND.( ln_asmiau ) ) &
219	& CALL ctl_stop( ' ln_asmdin and ln_asmiau :', &
220	& ' Choose Direct Initialization OR Incremental Analysis Updating')
221
222	IF ( ( ( .NOT. ln_asmdin ).AND.( .NOT. ln_asmiau ) ) &
223	.AND.( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ) .OR. ( ln_seaiceinc) )) &
224	& CALL ctl_stop( ' One or more of ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc is set to .true.', &
225	& ' but ln_asmdin and ln_asmiau are both set to .false. :', &
226	& ' Inconsistent options')
227
228	IF ( ( niaufn /= 0 ).AND.( niaufn /= 1 ) ) &
229	& CALL ctl_stop( ' niaufn /= 0 or niaufn /=1 :', &
230	& ' Type IAU weighting function is invalid')
231
232	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ).AND.( .NOT. ln_seaiceinc ) &
233	& ) &
234	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc are set to .false. :', &
235	& ' The assimilation increments are not applied')
236
237	IF ( ( ln_asmiau ).AND.( nitiaustr == nitiaufin ) ) &
238	& CALL ctl_stop( ' nitiaustr = nitiaufin :', &
239	& ' IAU interval is of zero length')
240
241	IF ( ( ln_asmiau ).AND.( ( nitiaustr_r < nit000 ).OR.( nitiaufin_r > nitend ) ) ) &
242	& CALL ctl_stop( ' nitiaustr or nitiaufin :', &
243	& ' IAU starting or final time step is outside the cycle interval', &
244	& ' Valid range nit000 to nitend')
245
246	IF ( ( nitbkg_r < nit000 - 1 ).OR.( nitbkg_r > nitend ) ) &
247	& CALL ctl_stop( ' nitbkg :', &
248	& ' Background time step is outside the cycle interval')
249
250	IF ( ( nitdin_r < nit000 - 1 ).OR.( nitdin_r > nitend ) ) &
251	& CALL ctl_stop( ' nitdin :', &
252	& ' Background time step for Direct Initialization is outside', &
253	& ' the cycle interval')
254
255	IF ( nstop > 0 ) RETURN ! if there are any errors then go no further
256
257	!--------------------------------------------------------------------
258	! Initialize the Incremental Analysis Updating weighting function
259	!--------------------------------------------------------------------
260
261	IF ( ln_asmiau ) THEN
262
263	ALLOCATE( wgtiau( icycper ) )
264
265	wgtiau(:) = 0.0
266
267	IF ( niaufn == 0 ) THEN
268
269	!---------------------------------------------------------
270	! Constant IAU forcing
271	!---------------------------------------------------------
272
273	DO jt = 1, iiauper
274	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
275	END DO
276
277	ELSEIF ( niaufn == 1 ) THEN
278
279	!---------------------------------------------------------
280	! Linear hat-like, centred in middle of IAU interval
281	!---------------------------------------------------------
282
283	! Compute the normalization factor
284	znorm = 0.0
285	IF ( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
286	imid = iiauper / 2
287	DO jt = 1, imid
288	znorm = znorm + REAL( jt )
289	END DO
290	znorm = 2.0 * znorm
291	ELSE ! Odd number of time steps in IAU interval
292	imid = ( iiauper + 1 ) / 2
293	DO jt = 1, imid - 1
294	znorm = znorm + REAL( jt )
295	END DO
296	znorm = 2.0 * znorm + REAL( imid )
297	ENDIF
298	znorm = 1.0 / znorm
299
300	DO jt = 1, imid - 1
301	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
302	END DO
303	DO jt = imid, iiauper
304	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
305	END DO
306
307	ENDIF
308
309	! Test that the integral of the weights over the weighting interval equals 1
310	IF(lwp) THEN
311	WRITE(numout,*)
312	WRITE(numout,*) 'asm_inc_init : IAU weights'
313	WRITE(numout,*) '~~~~~~~~~~~~'
314	WRITE(numout,*) ' time step IAU weight'
315	WRITE(numout,*) ' ========= ====================='
316	ztotwgt = 0.0
317	DO jt = 1, icycper
318	ztotwgt = ztotwgt + wgtiau(jt)
319	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
320	END DO
321	WRITE(numout,*) ' ==================================='
322	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
323	WRITE(numout,*) ' ==================================='
324	ENDIF
325
326	ENDIF
327
328	!--------------------------------------------------------------------
329	! Allocate and initialize the increment arrays
330	!--------------------------------------------------------------------
331
332	ALLOCATE( t_bkginc(jpi,jpj,jpk) )
333	ALLOCATE( s_bkginc(jpi,jpj,jpk) )
334	ALLOCATE( u_bkginc(jpi,jpj,jpk) )
335	ALLOCATE( v_bkginc(jpi,jpj,jpk) )
336	ALLOCATE( ssh_bkginc(jpi,jpj) )
337	ALLOCATE( seaice_bkginc(jpi,jpj))
338	#if defined key_asminc
339	ALLOCATE( ssh_iau(jpi,jpj) )
340	#endif
341	t_bkginc(:,:,:) = 0.0
342	s_bkginc(:,:,:) = 0.0
343	u_bkginc(:,:,:) = 0.0
344	v_bkginc(:,:,:) = 0.0
345	ssh_bkginc(:,:) = 0.0
346	seaice_bkginc(:,:) = 0.0
347	#if defined key_asminc
348	ssh_iau(:,:) = 0.0
349	#endif
350	IF ( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ).OR.( ln_seaiceinc ) ) THEN
351
352	!--------------------------------------------------------------------
353	! Read the increments from file
354	!--------------------------------------------------------------------
355
356	CALL iom_open( c_asminc, inum )
357
358	CALL iom_get( inum, 'time', zdate_inc )
359
360	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
361	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
362	z_inc_dateb = zdate_inc
363	z_inc_datef = zdate_inc
364
365	IF(lwp) THEN
366	WRITE(numout,*)
367	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid ', &
368	& ' between dates ', NINT( z_inc_dateb ),' and ', &
369	& NINT( z_inc_datef )
370	WRITE(numout,*) '~~~~~~~~~~~~'
371	ENDIF
372
373	IF ( ( NINT( z_inc_dateb ) < ndastp ) &
374	& .OR.( NINT( z_inc_datef ) > iitend_date ) ) &
375	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
376	& ' outside the assimilation interval' )
377
378	IF ( ( ln_asmdin ).AND.( NINT( zdate_inc ) /= iitdin_date ) ) &
379	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
380	& ' not agree with Direct Initialization time' )
381
382	IF ( ln_trainc ) THEN
383	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
384	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
385	! Apply the masks
386	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
387	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
388	! Set missing increments to 0.0 rather than 1e+20
389	! to allow for differences in masks
390	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
391	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
392	ENDIF
393
394	IF ( ln_dyninc ) THEN
395	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
396	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
397	! Apply the masks
398	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
399	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
400	! Set missing increments to 0.0 rather than 1e+20
401	! to allow for differences in masks
402	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
403	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
404	ENDIF
405
406	IF ( ln_sshinc ) THEN
407	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
408	! Apply the masks
409	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
410	! Set missing increments to 0.0 rather than 1e+20
411	! to allow for differences in masks
412	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
413	ENDIF
414
415	IF ( ln_seaiceinc ) THEN
416	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
417	! Apply the masks
418	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
419	! Set missing increments to 0.0 rather than 1e+20
420	! to allow for differences in masks
421	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
422	ENDIF
423
424	CALL iom_close( inum )
425
426	ENDIF
427
428	!-----------------------------------------------------------------------
429	! Apply divergence damping filter
430	!-----------------------------------------------------------------------
431
432	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN
433
434	CALL wrk_alloc(jpi,jpj,hdiv)
435
436	DO jt = 1, nn_divdmp
437
438	DO jk = 1, jpkm1
439
440	hdiv(:,:) = 0._wp
441
442	DO jj = 2, jpjm1
443	DO ji = fs_2, fs_jpim1 ! vector opt.
444	hdiv(ji,jj) = &
445	( e2u(ji ,jj ) * fse3u(ji ,jj ,jk) * u_bkginc(ji ,jj ,jk) &
446	- e2u(ji-1,jj ) * fse3u(ji-1,jj ,jk) * u_bkginc(ji-1,jj ,jk) &
447	+ e1v(ji ,jj ) * fse3v(ji ,jj ,jk) * v_bkginc(ji ,jj ,jk) &
448	- e1v(ji ,jj-1) * fse3v(ji ,jj-1,jk) * v_bkginc(ji ,jj-1,jk) ) &
449	/ ( e1t(ji,jj) * e2t(ji,jj) * fse3t(ji,jj,jk) )
450	END DO
451	END DO
452
453	CALL lbc_lnk( hdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
454
455	DO jj = 2, jpjm1
456	DO ji = fs_2, fs_jpim1 ! vector opt.
457	u_bkginc(ji,jj,jk) = u_bkginc(ji,jj,jk) + 0.2_wp * ( e1t(ji+1,jj)e2t(ji+1,jj) hdiv(ji+1,jj) &
458	- e1t(ji ,jj)e2t(ji ,jj) hdiv(ji ,jj) ) &
459	/ e1u(ji,jj) * umask(ji,jj,jk)
460	v_bkginc(ji,jj,jk) = v_bkginc(ji,jj,jk) + 0.2_wp * ( e1t(ji,jj+1)e2t(ji,jj+1) hdiv(ji,jj+1) &
461	- e1t(ji,jj )e2t(ji,jj ) hdiv(ji,jj ) ) &
462	/ e2v(ji,jj) * vmask(ji,jj,jk)
463	END DO
464	END DO
465
466	END DO
467
468	END DO
469
470	CALL wrk_dealloc(jpi,jpj,hdiv)
471
472	ENDIF
473
474
475
476	!-----------------------------------------------------------------------
477	! Allocate and initialize the background state arrays
478	!-----------------------------------------------------------------------
479
480	IF ( ln_asmdin ) THEN
481
482	ALLOCATE( t_bkg(jpi,jpj,jpk) )
483	ALLOCATE( s_bkg(jpi,jpj,jpk) )
484	ALLOCATE( u_bkg(jpi,jpj,jpk) )
485	ALLOCATE( v_bkg(jpi,jpj,jpk) )
486	ALLOCATE( ssh_bkg(jpi,jpj) )
487
488	t_bkg(:,:,:) = 0.0
489	s_bkg(:,:,:) = 0.0
490	u_bkg(:,:,:) = 0.0
491	v_bkg(:,:,:) = 0.0
492	ssh_bkg(:,:) = 0.0
493
494	!--------------------------------------------------------------------
495	! Read from file the background state at analysis time
496	!--------------------------------------------------------------------
497
498	CALL iom_open( c_asmdin, inum )
499
500	CALL iom_get( inum, 'rdastp', zdate_bkg )
501
502	IF(lwp) THEN
503	WRITE(numout,*)
504	WRITE(numout,*) 'asm_inc_init : Assimilation background state valid at : ', &
505	& NINT( zdate_bkg )
506	WRITE(numout,*) '~~~~~~~~~~~~'
507	ENDIF
508
509	IF ( NINT( zdate_bkg ) /= iitdin_date ) &
510	& CALL ctl_warn( ' Validity time of assimilation background state does', &
511	& ' not agree with Direct Initialization time' )
512
513	IF ( ln_trainc ) THEN
514	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
515	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
516	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
517	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
518	ENDIF
519
520	IF ( ln_dyninc ) THEN
521	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
522	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
523	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
524	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
525	ENDIF
526
527	IF ( ln_sshinc ) THEN
528	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
529	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
530	ENDIF
531
532	CALL iom_close( inum )
533
534	ENDIF
535	!
536	END SUBROUTINE asm_inc_init
537
538
539	SUBROUTINE calc_date( kit000, kt, kdate0, kdate )
540	!!----------------------------------------------------------------------
541	!! * ROUTINE calc_date *
542	!!
543	!! ** Purpose : Compute the calendar date YYYYMMDD at a given time step.
544	!!
545	!! ** Method : Compute the calendar date YYYYMMDD at a given time step.
546	!!
547	!! ** Action :
548	!!----------------------------------------------------------------------
549	INTEGER, INTENT(IN) :: kit000 ! Initial time step
550	INTEGER, INTENT(IN) :: kt ! Current time step referenced to kit000
551	INTEGER, INTENT(IN) :: kdate0 ! Initial date
552	INTEGER, INTENT(OUT) :: kdate ! Current date reference to kdate0
553	!
554	INTEGER :: iyea0 ! Initial year
555	INTEGER :: imon0 ! Initial month
556	INTEGER :: iday0 ! Initial day
557	INTEGER :: iyea ! Current year
558	INTEGER :: imon ! Current month
559	INTEGER :: iday ! Current day
560	INTEGER :: idaystp ! Number of days between initial and current date
561	INTEGER :: idaycnt ! Day counter
562
563	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
564
565	!-----------------------------------------------------------------------
566	! Compute the calendar date YYYYMMDD
567	!-----------------------------------------------------------------------
568
569	! Initial date
570	iyea0 = kdate0 / 10000
571	imon0 = ( kdate0 - ( iyea0 * 10000 ) ) / 100
572	iday0 = kdate0 - ( iyea0 * 10000 ) - ( imon0 * 100 )
573
574	! Check that kt >= kit000 - 1
575	IF ( kt < kit000 - 1 ) CALL ctl_stop( ' kt must be >= kit000 - 1')
576
577	! If kt = kit000 - 1 then set the date to the restart date
578	IF ( kt == kit000 - 1 ) THEN
579
580	kdate = ndastp
581	RETURN
582
583	ENDIF
584
585	! Compute the number of days from the initial date
586	idaystp = INT( REAL( kt - kit000 ) * rdt / 86400. )
587
588	iday = iday0
589	imon = imon0
590	iyea = iyea0
591	idaycnt = 0
592
593	CALL calc_month_len( iyea, imonth_len )
594
595	DO WHILE ( idaycnt < idaystp )
596	iday = iday + 1
597	IF ( iday > imonth_len(imon) ) THEN
598	iday = 1
599	imon = imon + 1
600	ENDIF
601	IF ( imon > 12 ) THEN
602	imon = 1
603	iyea = iyea + 1
604	CALL calc_month_len( iyea, imonth_len ) ! update month lengths
605	ENDIF
606	idaycnt = idaycnt + 1
607	END DO
608	!
609	kdate = iyea * 10000 + imon * 100 + iday
610	!
611	END SUBROUTINE
612
613
614	SUBROUTINE calc_month_len( iyear, imonth_len )
615	!!----------------------------------------------------------------------
616	!! * ROUTINE calc_month_len *
617	!!
618	!! ** Purpose : Compute the number of days in a months given a year.
619	!!
620	!! ** Method :
621	!!----------------------------------------------------------------------
622	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
623	INTEGER :: iyear !: year
624	!!----------------------------------------------------------------------
625	!
626	! length of the month of the current year (from nleapy, read in namelist)
627	IF ( nleapy < 2 ) THEN
628	imonth_len(:) = (/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
629	IF ( nleapy == 1 ) THEN ! we are using calendar with leap years
630	IF ( MOD(iyear, 4) == 0 .AND. ( MOD(iyear, 400) == 0 .OR. MOD(iyear, 100) /= 0 ) ) THEN
631	imonth_len(2) = 29
632	ENDIF
633	ENDIF
634	ELSE
635	imonth_len(:) = nleapy ! all months with nleapy days per year
636	ENDIF
637	!
638	END SUBROUTINE
639
640
641	SUBROUTINE tra_asm_inc( kt )
642	!!----------------------------------------------------------------------
643	!! * ROUTINE tra_asm_inc *
644	!!
645	!! ** Purpose : Apply the tracer (T and S) assimilation increments
646	!!
647	!! ** Method : Direct initialization or Incremental Analysis Updating
648	!!
649	!! ** Action :
650	!!----------------------------------------------------------------------
651	INTEGER, INTENT(IN) :: kt ! Current time step
652	!
653	INTEGER :: ji,jj,jk
654	INTEGER :: it
655	REAL(wp) :: zincwgt ! IAU weight for current time step
656	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
657	!!----------------------------------------------------------------------
658
659	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
660	! used to prevent the applied increments taking the temperature below the local freezing point
661
662	DO jk = 1, jpkm1
663	CALL eos_fzp( tsn(:,:,jk,jp_sal), fzptnz(:,:,jk), fsdept(:,:,jk) )
664	END DO
665
666	IF ( ln_asmiau ) THEN
667
668	!--------------------------------------------------------------------
669	! Incremental Analysis Updating
670	!--------------------------------------------------------------------
671
672	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
673
674	it = kt - nit000 + 1
675	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
676
677	IF(lwp) THEN
678	WRITE(numout,*)
679	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
680	WRITE(numout,*) '~~~~~~~~~~~~'
681	ENDIF
682
683	! Update the tracer tendencies
684	DO jk = 1, jpkm1
685	IF (ln_temnofreeze) THEN
686	! Do not apply negative increments if the temperature will fall below freezing
687	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
688	& tsn(:,:,jk,jp_tem) + tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
689	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
690	END WHERE
691	ELSE
692	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
693	ENDIF
694	IF (ln_salfix) THEN
695	! Do not apply negative increments if the salinity will fall below a specified
696	! minimum value salfixmin
697	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
698	& tsn(:,:,jk,jp_sal) + tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
699	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
700	END WHERE
701	ELSE
702	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
703	ENDIF
704	END DO
705
706	ENDIF
707
708	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
709	DEALLOCATE( t_bkginc )
710	DEALLOCATE( s_bkginc )
711	ENDIF
712
713
714	ELSEIF ( ln_asmdin ) THEN
715
716	!--------------------------------------------------------------------
717	! Direct Initialization
718	!--------------------------------------------------------------------
719
720	IF ( kt == nitdin_r ) THEN
721
722	neuler = 0 ! Force Euler forward step
723
724	! Initialize the now fields with the background + increment
725	IF (ln_temnofreeze) THEN
726	! Do not apply negative increments if the temperature will fall below freezing
727	WHERE( t_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
728	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
729	END WHERE
730	ELSE
731	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
732	ENDIF
733	IF (ln_salfix) THEN
734	! Do not apply negative increments if the salinity will fall below a specified
735	! minimum value salfixmin
736	WHERE( s_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
737	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
738	END WHERE
739	ELSE
740	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
741	ENDIF
742
743	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
744
745	CALL eos( tsb, rhd, rhop, gdept_0(:,:,:) ) ! Before potential and in situ densities
746	!!gm fabien
747	! CALL eos( tsb, rhd, rhop ) ! Before potential and in situ densities
748	!!gm
749
750
751	IF( ln_zps .AND. .NOT. lk_c1d .AND. .NOT. ln_isfcav) &
752	& CALL zps_hde ( kt, jpts, tsb, gtsu, gtsv, & ! Partial steps: before horizontal gradient
753	& rhd, gru , grv ) ! of t, s, rd at the last ocean level
754	IF( ln_zps .AND. .NOT. lk_c1d .AND. ln_isfcav) &
755	& CALL zps_hde_isf( nit000, jpts, tsb, gtsu, gtsv, & ! Partial steps for top cell (ISF)
756	& rhd, gru , grv , aru , arv , gzu , gzv , ge3ru , ge3rv , &
757	& gtui, gtvi, grui, grvi, arui, arvi, gzui, gzvi, ge3rui, ge3rvi ) ! of t, s, rd at the last ocean level
758
759	#if defined key_zdfkpp
760	CALL eos( tsn, rhd, fsdept_n(:,:,:) ) ! Compute rhd
761	!!gm fabien CALL eos( tsn, rhd ) ! Compute rhd
762	#endif
763
764	DEALLOCATE( t_bkginc )
765	DEALLOCATE( s_bkginc )
766	DEALLOCATE( t_bkg )
767	DEALLOCATE( s_bkg )
768	ENDIF
769	!
770	ENDIF
771	!
772	END SUBROUTINE tra_asm_inc
773
774
775	SUBROUTINE dyn_asm_inc( kt )
776	!!----------------------------------------------------------------------
777	!! * ROUTINE dyn_asm_inc *
778	!!
779	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
780	!!
781	!! ** Method : Direct initialization or Incremental Analysis Updating.
782	!!
783	!! ** Action :
784	!!----------------------------------------------------------------------
785	INTEGER, INTENT(IN) :: kt ! Current time step
786	!
787	INTEGER :: jk
788	INTEGER :: it
789	REAL(wp) :: zincwgt ! IAU weight for current time step
790	!!----------------------------------------------------------------------
791
792	IF ( ln_asmiau ) THEN
793
794	!--------------------------------------------------------------------
795	! Incremental Analysis Updating
796	!--------------------------------------------------------------------
797
798	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
799
800	it = kt - nit000 + 1
801	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
802
803	IF(lwp) THEN
804	WRITE(numout,*)
805	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', &
806	& kt,' with IAU weight = ', wgtiau(it)
807	WRITE(numout,*) '~~~~~~~~~~~~'
808	ENDIF
809
810	! Update the dynamic tendencies
811	DO jk = 1, jpkm1
812	ua(:,:,jk) = ua(:,:,jk) + u_bkginc(:,:,jk) * zincwgt
813	va(:,:,jk) = va(:,:,jk) + v_bkginc(:,:,jk) * zincwgt
814	END DO
815
816	IF ( kt == nitiaufin_r ) THEN
817	DEALLOCATE( u_bkginc )
818	DEALLOCATE( v_bkginc )
819	ENDIF
820
821	ENDIF
822
823	ELSEIF ( ln_asmdin ) THEN
824
825	!--------------------------------------------------------------------
826	! Direct Initialization
827	!--------------------------------------------------------------------
828
829	IF ( kt == nitdin_r ) THEN
830
831	neuler = 0 ! Force Euler forward step
832
833	! Initialize the now fields with the background + increment
834	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
835	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
836
837	ub(:,:,:) = un(:,:,:) ! Update before fields
838	vb(:,:,:) = vn(:,:,:)
839
840	DEALLOCATE( u_bkg )
841	DEALLOCATE( v_bkg )
842	DEALLOCATE( u_bkginc )
843	DEALLOCATE( v_bkginc )
844	ENDIF
845	!
846	ENDIF
847	!
848	END SUBROUTINE dyn_asm_inc
849
850
851	SUBROUTINE ssh_asm_inc( kt )
852	!!----------------------------------------------------------------------
853	!! * ROUTINE ssh_asm_inc *
854	!!
855	!! ** Purpose : Apply the sea surface height assimilation increment.
856	!!
857	!! ** Method : Direct initialization or Incremental Analysis Updating.
858	!!
859	!! ** Action :
860	!!----------------------------------------------------------------------
861	INTEGER, INTENT(IN) :: kt ! Current time step
862	!
863	INTEGER :: it
864	INTEGER :: jk
865	REAL(wp) :: zincwgt ! IAU weight for current time step
866	!!----------------------------------------------------------------------
867
868	IF ( ln_asmiau ) THEN
869
870	!--------------------------------------------------------------------
871	! Incremental Analysis Updating
872	!--------------------------------------------------------------------
873
874	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
875
876	it = kt - nit000 + 1
877	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
878
879	IF(lwp) THEN
880	WRITE(numout,*)
881	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
882	& kt,' with IAU weight = ', wgtiau(it)
883	WRITE(numout,*) '~~~~~~~~~~~~'
884	ENDIF
885
886	! Save the tendency associated with the IAU weighted SSH increment
887	! (applied in dynspg.*)
888	#if defined key_asminc
889	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
890	#endif
891	IF ( kt == nitiaufin_r ) THEN
892	DEALLOCATE( ssh_bkginc )
893	ENDIF
894
895	ENDIF
896
897	ELSEIF ( ln_asmdin ) THEN
898
899	!--------------------------------------------------------------------
900	! Direct Initialization
901	!--------------------------------------------------------------------
902
903	IF ( kt == nitdin_r ) THEN
904
905	neuler = 0 ! Force Euler forward step
906
907	! Initialize the now fields the background + increment
908	sshn(:,:) = ssh_bkg(:,:) + ssh_bkginc(:,:)
909
910	! Update before fields
911	sshb(:,:) = sshn(:,:)
912
913	IF( lk_vvl ) THEN
914	DO jk = 1, jpk
915	fse3t_b(:,:,jk) = fse3t_n(:,:,jk)
916	END DO
917	ENDIF
918
919	DEALLOCATE( ssh_bkg )
920	DEALLOCATE( ssh_bkginc )
921
922	ENDIF
923	!
924	ENDIF
925	!
926	END SUBROUTINE ssh_asm_inc
927
928
929	SUBROUTINE seaice_asm_inc( kt, kindic )
930	!!----------------------------------------------------------------------
931	!! * ROUTINE seaice_asm_inc *
932	!!
933	!! ** Purpose : Apply the sea ice assimilation increment.
934	!!
935	!! ** Method : Direct initialization or Incremental Analysis Updating.
936	!!
937	!! ** Action :
938	!!
939	!!----------------------------------------------------------------------
940	IMPLICIT NONE
941	!
942	INTEGER, INTENT(in) :: kt ! Current time step
943	INTEGER, INTENT(in), OPTIONAL :: kindic ! flag for disabling the deallocation
944	!
945	INTEGER :: it
946	REAL(wp) :: zincwgt ! IAU weight for current time step
947	#if defined key_lim2
948	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
949	REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
950	#endif
951	!!----------------------------------------------------------------------
952
953	IF ( ln_asmiau ) THEN
954
955	!--------------------------------------------------------------------
956	! Incremental Analysis Updating
957	!--------------------------------------------------------------------
958
959	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
960
961	it = kt - nit000 + 1
962	zincwgt = wgtiau(it) ! IAU weight for the current time step
963	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
964
965	IF(lwp) THEN
966	WRITE(numout,*)
967	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', &
968	& kt,' with IAU weight = ', wgtiau(it)
969	WRITE(numout,*) '~~~~~~~~~~~~'
970	ENDIF
971
972	! Sea-ice : LIM-3 case (to add)
973
974	#if defined key_lim2
975	! Sea-ice : LIM-2 case
976	zofrld (:,:) = frld(:,:)
977	zohicif(:,:) = hicif(:,:)
978	!
979	frld = MIN( MAX( frld (:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
980	pfrld = MIN( MAX( pfrld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
981	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
982	!
983	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
984	!
985	! Nudge sea ice depth to bring it up to a required minimum depth
986	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
987	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
988	ELSEWHERE
989	zhicifinc(:,:) = 0.0_wp
990	END WHERE
991	!
992	! nudge ice depth
993	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
994	phicif(:,:) = phicif(:,:) + zhicifinc(:,:)
995	!
996	! seaice salinity balancing (to add)
997	#endif
998
999	#if defined key_cice && defined key_asminc
1000	! Sea-ice : CICE case. Pass ice increment tendency into CICE
1001	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
1002	#endif
1003
1004	IF ( kt == nitiaufin_r ) THEN
1005	DEALLOCATE( seaice_bkginc )
1006	ENDIF
1007
1008	ELSE
1009
1010	#if defined key_cice && defined key_asminc
1011	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1012	ndaice_da(:,:) = 0.0_wp
1013	#endif
1014
1015	ENDIF
1016
1017	ELSEIF ( ln_asmdin ) THEN
1018
1019	!--------------------------------------------------------------------
1020	! Direct Initialization
1021	!--------------------------------------------------------------------
1022
1023	IF ( kt == nitdin_r ) THEN
1024
1025	neuler = 0 ! Force Euler forward step
1026
1027	! Sea-ice : LIM-3 case (to add)
1028
1029	#if defined key_lim2
1030	! Sea-ice : LIM-2 case.
1031	zofrld(:,:)=frld(:,:)
1032	zohicif(:,:)=hicif(:,:)
1033	!
1034	! Initialize the now fields the background + increment
1035	frld (:,:) = MIN( MAX( frld(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
1036	pfrld(:,:) = frld(:,:)
1037	fr_i (:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1038	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1039	!
1040	! Nudge sea ice depth to bring it up to a required minimum depth
1041	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1042	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1043	ELSEWHERE
1044	zhicifinc(:,:) = 0.0_wp
1045	END WHERE
1046	!
1047	! nudge ice depth
1048	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1049	phicif(:,:) = phicif(:,:)
1050	!
1051	! seaice salinity balancing (to add)
1052	#endif
1053
1054	#if defined key_cice && defined key_asminc
1055	! Sea-ice : CICE case. Pass ice increment tendency into CICE
1056	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
1057	#endif
1058	IF ( .NOT. PRESENT(kindic) ) THEN
1059	DEALLOCATE( seaice_bkginc )
1060	END IF
1061
1062	ELSE
1063
1064	#if defined key_cice && defined key_asminc
1065	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1066	ndaice_da(:,:) = 0.0_wp
1067	#endif
1068
1069	ENDIF
1070
1071	!#if defined defined key_lim2 \|\| defined key_cice
1072	!
1073	! IF (ln_seaicebal ) THEN
1074	! !! balancing salinity increments
1075	! !! simple case from limflx.F90 (doesn't include a mass flux)
1076	! !! assumption is that as ice concentration is reduced or increased
1077	! !! the snow and ice depths remain constant
1078	! !! note that snow is being created where ice concentration is being increased
1079	! !! - could be more sophisticated and
1080	! !! not do this (but would need to alter h_snow)
1081	!
1082	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
1083	!
1084	! DO jj = 1, jpj
1085	! DO ji = 1, jpi
1086	! ! calculate change in ice and snow mass per unit area
1087	! ! positive values imply adding salt to the ocean (results from ice formation)
1088	! ! fwf : ice formation and melting
1089	!
1090	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
1091	!
1092	! ! change salinity down to mixed layer depth
1093	! mld=hmld_kara(ji,jj)
1094	!
1095	! ! prevent small mld
1096	! ! less than 10m can cause salinity instability
1097	! IF (mld < 10) mld=10
1098	!
1099	! ! set to bottom of a level
1100	! DO jk = jpk-1, 2, -1
1101	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
1102	! mld=gdepw(ji,jj,jk+1)
1103	! jkmax=jk
1104	! ENDIF
1105	! ENDDO
1106	!
1107	! ! avoid applying salinity balancing in shallow water or on land
1108	! !
1109	!
1110	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
1111	!
1112	! dsal_ocn=0.0_wp
1113	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
1114	!
1115	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
1116	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
1117	!
1118	! ! put increments in for levels in the mixed layer
1119	! ! but prevent salinity below a threshold value
1120	!
1121	! DO jk = 1, jkmax
1122	!
1123	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
1124	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
1125	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
1126	! ENDIF
1127	!
1128	! ENDDO
1129	!
1130	! ! ! salt exchanges at the ice/ocean interface
1131	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
1132	! !
1133	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
1134	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
1135	! !!
1136	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
1137	! !! ! E-P (kg m-2 s-2)
1138	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
1139	! ENDDO !ji
1140	! ENDDO !jj!
1141	!
1142	! ENDIF !ln_seaicebal
1143	!
1144	!#endif
1145
1146	ENDIF
1147
1148	END SUBROUTINE seaice_asm_inc
1149
1150	!!======================================================================
1151	END MODULE asminc

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