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asminc.F90 in branches/UKMO/r6232_obs_oper_update/NEMOGCM/NEMO/OPA_SRC/ASM – NEMO

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source: branches/UKMO/r6232_obs_oper_update/NEMOGCM/NEMO/OPA_SRC/ASM/asminc.F90 @ 11202

Last change on this file since 11202 was 11202, checked in by jcastill, 5 years ago
Copy of branch branches/UKMO/dev_r5518_obs_oper_update@11130 without namelist_ref changes to allow merging with coupling and biogeochemistry branches
Property svn:keywords set to `Id`
File size: 49.0 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	USE sbc_oce ! Surface boundary condition variables.
42
43	IMPLICIT NONE
44	PRIVATE
45
46	PUBLIC asm_inc_init !: Initialize the increment arrays and IAU weights
47	PUBLIC calc_date !: Compute the calendar date YYYYMMDD on a given step
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 seaice_asm_inc !: Apply the seaice increment
52
53	#if defined key_asminc
54	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
55	#else
56	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
57	#endif
58	LOGICAL, PUBLIC :: ln_bkgwri = .FALSE. !: No output of the background state fields
59	LOGICAL, PUBLIC :: ln_asmiau = .FALSE. !: No applying forcing with an assimilation increment
60	LOGICAL, PUBLIC :: ln_asmdin = .FALSE. !: No direct initialization
61	LOGICAL, PUBLIC :: ln_trainc = .FALSE. !: No tracer (T and S) assimilation increments
62	LOGICAL, PUBLIC :: ln_dyninc = .FALSE. !: No dynamics (u and v) assimilation increments
63	LOGICAL, PUBLIC :: ln_sshinc = .FALSE. !: No sea surface height assimilation increment
64	LOGICAL, PUBLIC :: ln_seaiceinc !: No sea ice concentration increment
65	LOGICAL, PUBLIC :: ln_salfix = .FALSE. !: Apply minimum salinity check
66	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
67	INTEGER, PUBLIC :: nn_divdmp !: Apply divergence damping filter nn_divdmp times
68
69	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkg , s_bkg !: Background temperature and salinity
70	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkg , v_bkg !: Background u- & v- velocity components
71	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkginc, s_bkginc !: Increment to the background T & S
72	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkginc, v_bkginc !: Increment to the u- & v-components
73	REAL(wp), PUBLIC, DIMENSION(:) , ALLOCATABLE :: wgtiau !: IAU weights for each time step
74	REAL(wp), PUBLIC, DIMENSION(:,:) , ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
75	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
76	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
77	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
78	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
79	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
80	!
81	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
82	! !: = 1 Linear hat-like, centred in middle of IAU interval
83	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
84
85	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
86	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
87
88	!! * Substitutions
89	# include "domzgr_substitute.h90"
90	# include "ldfdyn_substitute.h90"
91	# include "vectopt_loop_substitute.h90"
92	!!----------------------------------------------------------------------
93	!! NEMO/OPA 3.3 , NEMO Consortium (2010)
94	!! $Id$
95	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
96	!!----------------------------------------------------------------------
97	CONTAINS
98
99	SUBROUTINE asm_inc_init
100	!!----------------------------------------------------------------------
101	!! * ROUTINE asm_inc_init *
102	!!
103	!! ** Purpose : Initialize the assimilation increment and IAU weights.
104	!!
105	!! ** Method : Initialize the assimilation increment and IAU weights.
106	!!
107	!! ** Action :
108	!!----------------------------------------------------------------------
109	INTEGER :: ji, jj, jk, jt ! dummy loop indices
110	INTEGER :: imid, inum ! local integers
111	INTEGER :: ios ! Local integer output status for namelist read
112	INTEGER :: iiauper ! Number of time steps in the IAU period
113	INTEGER :: icycper ! Number of time steps in the cycle
114	INTEGER :: iitend_date ! Date YYYYMMDD of final time step
115	INTEGER :: iitbkg_date ! Date YYYYMMDD of background time step for Jb term
116	INTEGER :: iitdin_date ! Date YYYYMMDD of background time step for DI
117	INTEGER :: iitiaustr_date ! Date YYYYMMDD of IAU interval start time step
118	INTEGER :: iitiaufin_date ! Date YYYYMMDD of IAU interval final time step
119	!
120	REAL(wp) :: znorm ! Normalization factor for IAU weights
121	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights (should be equal to one)
122	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
123	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
124	REAL(wp) :: zdate_bkg ! Date in background state file for DI
125	REAL(wp) :: zdate_inc ! Time axis in increments file
126	!
127	REAL(wp), POINTER, DIMENSION(:,:) :: hdiv ! 2D workspace
128	!!
129	NAMELIST/nam_asminc/ ln_bkgwri, &
130	& ln_trainc, ln_dyninc, ln_sshinc, &
131	& ln_asmdin, ln_asmiau, &
132	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
133	& ln_salfix, salfixmin, nn_divdmp
134	!!----------------------------------------------------------------------
135
136	!-----------------------------------------------------------------------
137	! Read Namelist nam_asminc : assimilation increment interface
138	!-----------------------------------------------------------------------
139	ln_seaiceinc = .FALSE.
140	ln_temnofreeze = .FALSE.
141
142	REWIND( numnam_ref ) ! Namelist nam_asminc in reference namelist : Assimilation increment
143	READ ( numnam_ref, nam_asminc, IOSTAT = ios, ERR = 901)
144	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in reference namelist', lwp )
145
146	REWIND( numnam_cfg ) ! Namelist nam_asminc in configuration namelist : Assimilation increment
147	READ ( numnam_cfg, nam_asminc, IOSTAT = ios, ERR = 902 )
148	902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in configuration namelist', lwp )
149	IF(lwm) WRITE ( numond, nam_asminc )
150
151	! Control print
152	IF(lwp) THEN
153	WRITE(numout,*)
154	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
155	WRITE(numout,*) '~~~~~~~~~~~~'
156	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
157	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
158	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
159	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
160	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
161	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
162	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
163	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
164	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
165	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
166	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
167	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
168	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
169	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
170	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
171	ENDIF
172
173	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
174	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
175	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
176	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
177
178	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
179	icycper = nitend - nit000 + 1 ! Cycle interval length
180
181	CALL calc_date( nit000, nitend , ndate0, iitend_date ) ! Date of final time step
182	CALL calc_date( nit000, nitbkg_r , ndate0, iitbkg_date ) ! Background time for Jb referenced to ndate0
183	CALL calc_date( nit000, nitdin_r , ndate0, iitdin_date ) ! Background time for DI referenced to ndate0
184	CALL calc_date( nit000, nitiaustr_r, ndate0, iitiaustr_date ) ! IAU start time referenced to ndate0
185	CALL calc_date( nit000, nitiaufin_r, ndate0, iitiaufin_date ) ! IAU end time referenced to ndate0
186	!
187	IF(lwp) THEN
188	WRITE(numout,*)
189	WRITE(numout,*) ' Time steps referenced to current cycle:'
190	WRITE(numout,*) ' iitrst = ', nit000 - 1
191	WRITE(numout,*) ' nit000 = ', nit000
192	WRITE(numout,*) ' nitend = ', nitend
193	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
194	WRITE(numout,*) ' nitdin_r = ', nitdin_r
195	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
196	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
197	WRITE(numout,*)
198	WRITE(numout,*) ' Dates referenced to current cycle:'
199	WRITE(numout,*) ' ndastp = ', ndastp
200	WRITE(numout,*) ' ndate0 = ', ndate0
201	WRITE(numout,*) ' iitend_date = ', iitend_date
202	WRITE(numout,*) ' iitbkg_date = ', iitbkg_date
203	WRITE(numout,*) ' iitdin_date = ', iitdin_date
204	WRITE(numout,*) ' iitiaustr_date = ', iitiaustr_date
205	WRITE(numout,*) ' iitiaufin_date = ', iitiaufin_date
206	ENDIF
207
208	IF ( nacc /= 0 ) &
209	& CALL ctl_stop( ' nacc /= 0 and key_asminc :', &
210	& ' Assimilation increments have only been implemented', &
211	& ' for synchronous time stepping' )
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(:) = 0.0
261
262	IF ( niaufn == 0 ) THEN
263
264	!---------------------------------------------------------
265	! Constant IAU forcing
266	!---------------------------------------------------------
267
268	DO jt = 1, iiauper
269	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
270	END DO
271
272	ELSEIF ( niaufn == 1 ) THEN
273
274	!---------------------------------------------------------
275	! Linear hat-like, centred in middle of IAU interval
276	!---------------------------------------------------------
277
278	! Compute the normalization factor
279	znorm = 0.0
280	IF ( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
281	imid = iiauper / 2
282	DO jt = 1, imid
283	znorm = znorm + REAL( jt )
284	END DO
285	znorm = 2.0 * znorm
286	ELSE ! Odd number of time steps in IAU interval
287	imid = ( iiauper + 1 ) / 2
288	DO jt = 1, imid - 1
289	znorm = znorm + REAL( jt )
290	END DO
291	znorm = 2.0 * znorm + REAL( imid )
292	ENDIF
293	znorm = 1.0 / znorm
294
295	DO jt = 1, imid - 1
296	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
297	END DO
298	DO jt = imid, iiauper
299	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
300	END DO
301
302	ENDIF
303
304	! Test that the integral of the weights over the weighting interval equals 1
305	IF(lwp) THEN
306	WRITE(numout,*)
307	WRITE(numout,*) 'asm_inc_init : IAU weights'
308	WRITE(numout,*) '~~~~~~~~~~~~'
309	WRITE(numout,*) ' time step IAU weight'
310	WRITE(numout,*) ' ========= ====================='
311	ztotwgt = 0.0
312	DO jt = 1, icycper
313	ztotwgt = ztotwgt + wgtiau(jt)
314	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
315	END DO
316	WRITE(numout,*) ' ==================================='
317	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
318	WRITE(numout,*) ' ==================================='
319	ENDIF
320
321	ENDIF
322
323	!--------------------------------------------------------------------
324	! Allocate and initialize the increment arrays
325	!--------------------------------------------------------------------
326
327	ALLOCATE( t_bkginc(jpi,jpj,jpk) )
328	ALLOCATE( s_bkginc(jpi,jpj,jpk) )
329	ALLOCATE( u_bkginc(jpi,jpj,jpk) )
330	ALLOCATE( v_bkginc(jpi,jpj,jpk) )
331	ALLOCATE( ssh_bkginc(jpi,jpj) )
332	ALLOCATE( seaice_bkginc(jpi,jpj))
333	#if defined key_asminc
334	ALLOCATE( ssh_iau(jpi,jpj) )
335	#endif
336	t_bkginc(:,:,:) = 0.0
337	s_bkginc(:,:,:) = 0.0
338	u_bkginc(:,:,:) = 0.0
339	v_bkginc(:,:,:) = 0.0
340	ssh_bkginc(:,:) = 0.0
341	seaice_bkginc(:,:) = 0.0
342	#if defined key_asminc
343	ssh_iau(:,:) = 0.0
344	#endif
345	IF ( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ).OR.( ln_seaiceinc ) ) THEN
346
347	!--------------------------------------------------------------------
348	! Read the increments from file
349	!--------------------------------------------------------------------
350
351	CALL iom_open( c_asminc, inum )
352
353	CALL iom_get( inum, 'time', zdate_inc )
354
355	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
356	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
357	z_inc_dateb = zdate_inc
358	z_inc_datef = zdate_inc
359
360	IF(lwp) THEN
361	WRITE(numout,*)
362	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid ', &
363	& ' between dates ', NINT( z_inc_dateb ),' and ', &
364	& NINT( z_inc_datef )
365	WRITE(numout,*) '~~~~~~~~~~~~'
366	ENDIF
367
368	IF ( ( NINT( z_inc_dateb ) < ndastp ) &
369	& .OR.( NINT( z_inc_datef ) > iitend_date ) ) &
370	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
371	& ' outside the assimilation interval' )
372
373	IF ( ( ln_asmdin ).AND.( NINT( zdate_inc ) /= iitdin_date ) ) &
374	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
375	& ' not agree with Direct Initialization time' )
376
377	IF ( ln_trainc ) THEN
378	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
379	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
380	! Apply the masks
381	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
382	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
383	! Set missing increments to 0.0 rather than 1e+20
384	! to allow for differences in masks
385	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
386	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
387	ENDIF
388
389	IF ( ln_dyninc ) THEN
390	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
391	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
392	! Apply the masks
393	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
394	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
395	! Set missing increments to 0.0 rather than 1e+20
396	! to allow for differences in masks
397	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
398	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
399	ENDIF
400
401	IF ( ln_sshinc ) THEN
402	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
403	! Apply the masks
404	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
405	! Set missing increments to 0.0 rather than 1e+20
406	! to allow for differences in masks
407	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
408	ENDIF
409
410	IF ( ln_seaiceinc ) THEN
411	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
412	! Apply the masks
413	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
414	! Set missing increments to 0.0 rather than 1e+20
415	! to allow for differences in masks
416	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
417	ENDIF
418
419	CALL iom_close( inum )
420
421	ENDIF
422
423	!-----------------------------------------------------------------------
424	! Apply divergence damping filter
425	!-----------------------------------------------------------------------
426
427	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN
428
429	CALL wrk_alloc(jpi,jpj,hdiv)
430
431	DO jt = 1, nn_divdmp
432
433	DO jk = 1, jpkm1
434
435	hdiv(:,:) = 0._wp
436
437	DO jj = 2, jpjm1
438	DO ji = fs_2, fs_jpim1 ! vector opt.
439	hdiv(ji,jj) = &
440	( e2u(ji ,jj ) * fse3u(ji ,jj ,jk) * u_bkginc(ji ,jj ,jk) &
441	- e2u(ji-1,jj ) * fse3u(ji-1,jj ,jk) * u_bkginc(ji-1,jj ,jk) &
442	+ e1v(ji ,jj ) * fse3v(ji ,jj ,jk) * v_bkginc(ji ,jj ,jk) &
443	- e1v(ji ,jj-1) * fse3v(ji ,jj-1,jk) * v_bkginc(ji ,jj-1,jk) ) &
444	/ ( e1t(ji,jj) * e2t(ji,jj) * fse3t(ji,jj,jk) )
445	END DO
446	END DO
447
448	CALL lbc_lnk( hdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
449
450	DO jj = 2, jpjm1
451	DO ji = fs_2, fs_jpim1 ! vector opt.
452	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) &
453	- e1t(ji ,jj)e2t(ji ,jj) hdiv(ji ,jj) ) &
454	/ e1u(ji,jj) * umask(ji,jj,jk)
455	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) &
456	- e1t(ji,jj )e2t(ji,jj ) hdiv(ji,jj ) ) &
457	/ e2v(ji,jj) * vmask(ji,jj,jk)
458	END DO
459	END DO
460
461	END DO
462
463	END DO
464
465	CALL wrk_dealloc(jpi,jpj,hdiv)
466
467	ENDIF
468
469
470
471	!-----------------------------------------------------------------------
472	! Allocate and initialize the background state arrays
473	!-----------------------------------------------------------------------
474
475	IF ( ln_asmdin ) THEN
476
477	ALLOCATE( t_bkg(jpi,jpj,jpk) )
478	ALLOCATE( s_bkg(jpi,jpj,jpk) )
479	ALLOCATE( u_bkg(jpi,jpj,jpk) )
480	ALLOCATE( v_bkg(jpi,jpj,jpk) )
481	ALLOCATE( ssh_bkg(jpi,jpj) )
482
483	t_bkg(:,:,:) = 0.0
484	s_bkg(:,:,:) = 0.0
485	u_bkg(:,:,:) = 0.0
486	v_bkg(:,:,:) = 0.0
487	ssh_bkg(:,:) = 0.0
488
489	!--------------------------------------------------------------------
490	! Read from file the background state at analysis time
491	!--------------------------------------------------------------------
492
493	CALL iom_open( c_asmdin, inum )
494
495	CALL iom_get( inum, 'rdastp', zdate_bkg )
496
497	IF(lwp) THEN
498	WRITE(numout,*)
499	WRITE(numout,*) 'asm_inc_init : Assimilation background state valid at : ', &
500	& NINT( zdate_bkg )
501	WRITE(numout,*) '~~~~~~~~~~~~'
502	ENDIF
503
504	IF ( NINT( zdate_bkg ) /= iitdin_date ) &
505	& CALL ctl_warn( ' Validity time of assimilation background state does', &
506	& ' not agree with Direct Initialization time' )
507
508	IF ( ln_trainc ) THEN
509	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
510	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
511	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
512	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
513	ENDIF
514
515	IF ( ln_dyninc ) THEN
516	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
517	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
518	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
519	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
520	ENDIF
521
522	IF ( ln_sshinc ) THEN
523	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
524	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
525	ENDIF
526
527	CALL iom_close( inum )
528
529	ENDIF
530	!
531	END SUBROUTINE asm_inc_init
532
533
534	SUBROUTINE calc_date( kit000, kt, kdate0, kdate )
535	!!----------------------------------------------------------------------
536	!! * ROUTINE calc_date *
537	!!
538	!! ** Purpose : Compute the calendar date YYYYMMDD at a given time step.
539	!!
540	!! ** Method : Compute the calendar date YYYYMMDD at a given time step.
541	!!
542	!! ** Action :
543	!!----------------------------------------------------------------------
544	INTEGER, INTENT(IN) :: kit000 ! Initial time step
545	INTEGER, INTENT(IN) :: kt ! Current time step referenced to kit000
546	INTEGER, INTENT(IN) :: kdate0 ! Initial date
547	INTEGER, INTENT(OUT) :: kdate ! Current date reference to kdate0
548	!
549	INTEGER :: iyea0 ! Initial year
550	INTEGER :: imon0 ! Initial month
551	INTEGER :: iday0 ! Initial day
552	INTEGER :: iyea ! Current year
553	INTEGER :: imon ! Current month
554	INTEGER :: iday ! Current day
555	INTEGER :: idaystp ! Number of days between initial and current date
556	INTEGER :: idaycnt ! Day counter
557
558	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
559
560	!-----------------------------------------------------------------------
561	! Compute the calendar date YYYYMMDD
562	!-----------------------------------------------------------------------
563
564	! Initial date
565	iyea0 = kdate0 / 10000
566	imon0 = ( kdate0 - ( iyea0 * 10000 ) ) / 100
567	iday0 = kdate0 - ( iyea0 * 10000 ) - ( imon0 * 100 )
568
569	! Check that kt >= kit000 - 1
570	IF ( kt < kit000 - 1 ) CALL ctl_stop( ' kt must be >= kit000 - 1')
571
572	! If kt = kit000 - 1 then set the date to the restart date
573	IF ( kt == kit000 - 1 ) THEN
574
575	kdate = ndastp
576	RETURN
577
578	ENDIF
579
580	! Compute the number of days from the initial date
581	idaystp = INT( REAL( kt - kit000 ) * rdt / 86400. )
582
583	iday = iday0
584	imon = imon0
585	iyea = iyea0
586	idaycnt = 0
587
588	CALL calc_month_len( iyea, imonth_len )
589
590	DO WHILE ( idaycnt < idaystp )
591	iday = iday + 1
592	IF ( iday > imonth_len(imon) ) THEN
593	iday = 1
594	imon = imon + 1
595	ENDIF
596	IF ( imon > 12 ) THEN
597	imon = 1
598	iyea = iyea + 1
599	CALL calc_month_len( iyea, imonth_len ) ! update month lengths
600	ENDIF
601	idaycnt = idaycnt + 1
602	END DO
603	!
604	kdate = iyea * 10000 + imon * 100 + iday
605	!
606	END SUBROUTINE
607
608
609	SUBROUTINE calc_month_len( iyear, imonth_len )
610	!!----------------------------------------------------------------------
611	!! * ROUTINE calc_month_len *
612	!!
613	!! ** Purpose : Compute the number of days in a months given a year.
614	!!
615	!! ** Method :
616	!!----------------------------------------------------------------------
617	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
618	INTEGER :: iyear !: year
619	!!----------------------------------------------------------------------
620	!
621	! length of the month of the current year (from nleapy, read in namelist)
622	IF ( nleapy < 2 ) THEN
623	imonth_len(:) = (/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
624	IF ( nleapy == 1 ) THEN ! we are using calendar with leap years
625	IF ( MOD(iyear, 4) == 0 .AND. ( MOD(iyear, 400) == 0 .OR. MOD(iyear, 100) /= 0 ) ) THEN
626	imonth_len(2) = 29
627	ENDIF
628	ENDIF
629	ELSE
630	imonth_len(:) = nleapy ! all months with nleapy days per year
631	ENDIF
632	!
633	END SUBROUTINE
634
635
636	SUBROUTINE tra_asm_inc( kt )
637	!!----------------------------------------------------------------------
638	!! * ROUTINE tra_asm_inc *
639	!!
640	!! ** Purpose : Apply the tracer (T and S) assimilation increments
641	!!
642	!! ** Method : Direct initialization or Incremental Analysis Updating
643	!!
644	!! ** Action :
645	!!----------------------------------------------------------------------
646	INTEGER, INTENT(IN) :: kt ! Current time step
647	!
648	INTEGER :: ji,jj,jk
649	INTEGER :: it
650	REAL(wp) :: zincwgt ! IAU weight for current time step
651	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
652	!!----------------------------------------------------------------------
653
654	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
655	! used to prevent the applied increments taking the temperature below the local freezing point
656
657	DO jk = 1, jpkm1
658	CALL eos_fzp( tsn(:,:,jk,jp_sal), fzptnz(:,:,jk), fsdept(:,:,jk) )
659	END DO
660
661	IF ( ln_asmiau ) THEN
662
663	!--------------------------------------------------------------------
664	! Incremental Analysis Updating
665	!--------------------------------------------------------------------
666
667	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
668
669	it = kt - nit000 + 1
670	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
671
672	IF(lwp) THEN
673	WRITE(numout,*)
674	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
675	WRITE(numout,*) '~~~~~~~~~~~~'
676	ENDIF
677
678	! Update the tracer tendencies
679	DO jk = 1, jpkm1
680	IF (ln_temnofreeze) THEN
681	! Do not apply negative increments if the temperature will fall below freezing
682	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
683	& tsn(:,:,jk,jp_tem) + tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
684	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
685	END WHERE
686	ELSE
687	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
688	ENDIF
689	IF (ln_salfix) THEN
690	! Do not apply negative increments if the salinity will fall below a specified
691	! minimum value salfixmin
692	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
693	& tsn(:,:,jk,jp_sal) + tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
694	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
695	END WHERE
696	ELSE
697	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
698	ENDIF
699	END DO
700
701	ENDIF
702
703	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
704	DEALLOCATE( t_bkginc )
705	DEALLOCATE( s_bkginc )
706	ENDIF
707
708
709	ELSEIF ( ln_asmdin ) THEN
710
711	!--------------------------------------------------------------------
712	! Direct Initialization
713	!--------------------------------------------------------------------
714
715	IF ( kt == nitdin_r ) THEN
716
717	neuler = 0 ! Force Euler forward step
718
719	! Initialize the now fields with the background + increment
720	IF (ln_temnofreeze) THEN
721	! Do not apply negative increments if the temperature will fall below freezing
722	WHERE( t_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
723	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
724	END WHERE
725	ELSE
726	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
727	ENDIF
728	IF (ln_salfix) THEN
729	! Do not apply negative increments if the salinity will fall below a specified
730	! minimum value salfixmin
731	WHERE( s_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
732	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
733	END WHERE
734	ELSE
735	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
736	ENDIF
737
738	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
739
740	CALL eos( tsb, rhd, rhop, gdept_0(:,:,:) ) ! Before potential and in situ densities
741	!!gm fabien
742	! CALL eos( tsb, rhd, rhop ) ! Before potential and in situ densities
743	!!gm
744
745
746	IF( ln_zps .AND. .NOT. lk_c1d .AND. .NOT. ln_isfcav) &
747	& CALL zps_hde ( kt, jpts, tsb, gtsu, gtsv, & ! Partial steps: before horizontal gradient
748	& rhd, gru , grv ) ! of t, s, rd at the last ocean level
749	IF( ln_zps .AND. .NOT. lk_c1d .AND. ln_isfcav) &
750	& CALL zps_hde_isf( nit000, jpts, tsb, gtsu, gtsv, & ! Partial steps for top cell (ISF)
751	& rhd, gru , grv , aru , arv , gzu , gzv , ge3ru , ge3rv , &
752	& gtui, gtvi, grui, grvi, arui, arvi, gzui, gzvi, ge3rui, ge3rvi ) ! of t, s, rd at the last ocean level
753
754	#if defined key_zdfkpp
755	CALL eos( tsn, rhd, fsdept_n(:,:,:) ) ! Compute rhd
756	!!gm fabien CALL eos( tsn, rhd ) ! Compute rhd
757	#endif
758
759	DEALLOCATE( t_bkginc )
760	DEALLOCATE( s_bkginc )
761	DEALLOCATE( t_bkg )
762	DEALLOCATE( s_bkg )
763	ENDIF
764	!
765	ENDIF
766	! Perhaps the following call should be in step
767	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
768	!
769	END SUBROUTINE tra_asm_inc
770
771
772	SUBROUTINE dyn_asm_inc( kt )
773	!!----------------------------------------------------------------------
774	!! * ROUTINE dyn_asm_inc *
775	!!
776	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
777	!!
778	!! ** Method : Direct initialization or Incremental Analysis Updating.
779	!!
780	!! ** Action :
781	!!----------------------------------------------------------------------
782	INTEGER, INTENT(IN) :: kt ! Current time step
783	!
784	INTEGER :: jk
785	INTEGER :: it
786	REAL(wp) :: zincwgt ! IAU weight for current time step
787	!!----------------------------------------------------------------------
788
789	IF ( ln_asmiau ) THEN
790
791	!--------------------------------------------------------------------
792	! Incremental Analysis Updating
793	!--------------------------------------------------------------------
794
795	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
796
797	it = kt - nit000 + 1
798	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
799
800	IF(lwp) THEN
801	WRITE(numout,*)
802	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', &
803	& kt,' with IAU weight = ', wgtiau(it)
804	WRITE(numout,*) '~~~~~~~~~~~~'
805	ENDIF
806
807	! Update the dynamic tendencies
808	DO jk = 1, jpkm1
809	ua(:,:,jk) = ua(:,:,jk) + u_bkginc(:,:,jk) * zincwgt
810	va(:,:,jk) = va(:,:,jk) + v_bkginc(:,:,jk) * zincwgt
811	END DO
812
813	IF ( kt == nitiaufin_r ) THEN
814	DEALLOCATE( u_bkginc )
815	DEALLOCATE( v_bkginc )
816	ENDIF
817
818	ENDIF
819
820	ELSEIF ( ln_asmdin ) THEN
821
822	!--------------------------------------------------------------------
823	! Direct Initialization
824	!--------------------------------------------------------------------
825
826	IF ( kt == nitdin_r ) THEN
827
828	neuler = 0 ! Force Euler forward step
829
830	! Initialize the now fields with the background + increment
831	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
832	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
833
834	ub(:,:,:) = un(:,:,:) ! Update before fields
835	vb(:,:,:) = vn(:,:,:)
836
837	DEALLOCATE( u_bkg )
838	DEALLOCATE( v_bkg )
839	DEALLOCATE( u_bkginc )
840	DEALLOCATE( v_bkginc )
841	ENDIF
842	!
843	ENDIF
844	!
845	END SUBROUTINE dyn_asm_inc
846
847
848	SUBROUTINE ssh_asm_inc( kt )
849	!!----------------------------------------------------------------------
850	!! * ROUTINE ssh_asm_inc *
851	!!
852	!! ** Purpose : Apply the sea surface height assimilation increment.
853	!!
854	!! ** Method : Direct initialization or Incremental Analysis Updating.
855	!!
856	!! ** Action :
857	!!----------------------------------------------------------------------
858	INTEGER, INTENT(IN) :: kt ! Current time step
859	!
860	INTEGER :: it
861	INTEGER :: jk
862	REAL(wp) :: zincwgt ! IAU weight for current time step
863	!!----------------------------------------------------------------------
864
865	IF ( ln_asmiau ) THEN
866
867	!--------------------------------------------------------------------
868	! Incremental Analysis Updating
869	!--------------------------------------------------------------------
870
871	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
872
873	it = kt - nit000 + 1
874	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
875
876	IF(lwp) THEN
877	WRITE(numout,*)
878	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
879	& kt,' with IAU weight = ', wgtiau(it)
880	WRITE(numout,*) '~~~~~~~~~~~~'
881	ENDIF
882
883	! Save the tendency associated with the IAU weighted SSH increment
884	! (applied in dynspg.*)
885	#if defined key_asminc
886	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
887	#endif
888	IF ( kt == nitiaufin_r ) THEN
889	DEALLOCATE( ssh_bkginc )
890	ENDIF
891
892	ENDIF
893
894	ELSEIF ( ln_asmdin ) THEN
895
896	!--------------------------------------------------------------------
897	! Direct Initialization
898	!--------------------------------------------------------------------
899
900	IF ( kt == nitdin_r ) THEN
901
902	neuler = 0 ! Force Euler forward step
903
904	! Initialize the now fields the background + increment
905	sshn(:,:) = ssh_bkg(:,:) + ssh_bkginc(:,:)
906
907	! Update before fields
908	sshb(:,:) = sshn(:,:)
909
910	IF( lk_vvl ) THEN
911	DO jk = 1, jpk
912	fse3t_b(:,:,jk) = fse3t_n(:,:,jk)
913	END DO
914	ENDIF
915
916	DEALLOCATE( ssh_bkg )
917	DEALLOCATE( ssh_bkginc )
918
919	ENDIF
920	!
921	ENDIF
922	!
923	END SUBROUTINE ssh_asm_inc
924
925
926	SUBROUTINE seaice_asm_inc( kt, kindic )
927	!!----------------------------------------------------------------------
928	!! * ROUTINE seaice_asm_inc *
929	!!
930	!! ** Purpose : Apply the sea ice assimilation increment.
931	!!
932	!! ** Method : Direct initialization or Incremental Analysis Updating.
933	!!
934	!! ** Action :
935	!!
936	!!----------------------------------------------------------------------
937	IMPLICIT NONE
938	!
939	INTEGER, INTENT(in) :: kt ! Current time step
940	INTEGER, INTENT(in), OPTIONAL :: kindic ! flag for disabling the deallocation
941	!
942	INTEGER :: it
943	REAL(wp) :: zincwgt ! IAU weight for current time step
944	#if defined key_lim2
945	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
946	REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
947	#endif
948	!!----------------------------------------------------------------------
949
950	IF ( ln_asmiau ) THEN
951
952	!--------------------------------------------------------------------
953	! Incremental Analysis Updating
954	!--------------------------------------------------------------------
955
956	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
957
958	it = kt - nit000 + 1
959	zincwgt = wgtiau(it) ! IAU weight for the current time step
960	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
961
962	IF(lwp) THEN
963	WRITE(numout,*)
964	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', &
965	& kt,' with IAU weight = ', wgtiau(it)
966	WRITE(numout,*) '~~~~~~~~~~~~'
967	ENDIF
968
969	! Sea-ice : LIM-3 case (to add)
970
971	#if defined key_lim2
972	! Sea-ice : LIM-2 case
973	zofrld (:,:) = frld(:,:)
974	zohicif(:,:) = hicif(:,:)
975	!
976	frld = MIN( MAX( frld (:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
977	pfrld = MIN( MAX( pfrld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
978	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
979	!
980	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
981	!
982	! Nudge sea ice depth to bring it up to a required minimum depth
983	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
984	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
985	ELSEWHERE
986	zhicifinc(:,:) = 0.0_wp
987	END WHERE
988	!
989	! nudge ice depth
990	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
991	phicif(:,:) = phicif(:,:) + zhicifinc(:,:)
992	!
993	! seaice salinity balancing (to add)
994	#endif
995
996	#if defined key_cice && defined key_asminc
997	! Sea-ice : CICE case. Pass ice increment tendency into CICE
998	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
999	#endif
1000
1001	IF ( kt == nitiaufin_r ) THEN
1002	DEALLOCATE( seaice_bkginc )
1003	ENDIF
1004
1005	ELSE
1006
1007	#if defined key_cice && defined key_asminc
1008	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1009	ndaice_da(:,:) = 0.0_wp
1010	#endif
1011
1012	ENDIF
1013
1014	ELSEIF ( ln_asmdin ) THEN
1015
1016	!--------------------------------------------------------------------
1017	! Direct Initialization
1018	!--------------------------------------------------------------------
1019
1020	IF ( kt == nitdin_r ) THEN
1021
1022	neuler = 0 ! Force Euler forward step
1023
1024	! Sea-ice : LIM-3 case (to add)
1025
1026	#if defined key_lim2
1027	! Sea-ice : LIM-2 case.
1028	zofrld(:,:)=frld(:,:)
1029	zohicif(:,:)=hicif(:,:)
1030	!
1031	! Initialize the now fields the background + increment
1032	frld (:,:) = MIN( MAX( frld(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
1033	pfrld(:,:) = frld(:,:)
1034	fr_i (:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1035	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1036	!
1037	! Nudge sea ice depth to bring it up to a required minimum depth
1038	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1039	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1040	ELSEWHERE
1041	zhicifinc(:,:) = 0.0_wp
1042	END WHERE
1043	!
1044	! nudge ice depth
1045	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1046	phicif(:,:) = phicif(:,:)
1047	!
1048	! seaice salinity balancing (to add)
1049	#endif
1050
1051	#if defined key_cice && defined key_asminc
1052	! Sea-ice : CICE case. Pass ice increment tendency into CICE
1053	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
1054	#endif
1055	IF ( .NOT. PRESENT(kindic) ) THEN
1056	DEALLOCATE( seaice_bkginc )
1057	END IF
1058
1059	ELSE
1060
1061	#if defined key_cice && defined key_asminc
1062	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1063	ndaice_da(:,:) = 0.0_wp
1064	#endif
1065
1066	ENDIF
1067
1068	!#if defined defined key_lim2 \|\| defined key_cice
1069	!
1070	! IF (ln_seaicebal ) THEN
1071	! !! balancing salinity increments
1072	! !! simple case from limflx.F90 (doesn't include a mass flux)
1073	! !! assumption is that as ice concentration is reduced or increased
1074	! !! the snow and ice depths remain constant
1075	! !! note that snow is being created where ice concentration is being increased
1076	! !! - could be more sophisticated and
1077	! !! not do this (but would need to alter h_snow)
1078	!
1079	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
1080	!
1081	! DO jj = 1, jpj
1082	! DO ji = 1, jpi
1083	! ! calculate change in ice and snow mass per unit area
1084	! ! positive values imply adding salt to the ocean (results from ice formation)
1085	! ! fwf : ice formation and melting
1086	!
1087	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
1088	!
1089	! ! change salinity down to mixed layer depth
1090	! mld=hmld_kara(ji,jj)
1091	!
1092	! ! prevent small mld
1093	! ! less than 10m can cause salinity instability
1094	! IF (mld < 10) mld=10
1095	!
1096	! ! set to bottom of a level
1097	! DO jk = jpk-1, 2, -1
1098	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
1099	! mld=gdepw(ji,jj,jk+1)
1100	! jkmax=jk
1101	! ENDIF
1102	! ENDDO
1103	!
1104	! ! avoid applying salinity balancing in shallow water or on land
1105	! !
1106	!
1107	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
1108	!
1109	! dsal_ocn=0.0_wp
1110	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
1111	!
1112	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
1113	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
1114	!
1115	! ! put increments in for levels in the mixed layer
1116	! ! but prevent salinity below a threshold value
1117	!
1118	! DO jk = 1, jkmax
1119	!
1120	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
1121	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
1122	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
1123	! ENDIF
1124	!
1125	! ENDDO
1126	!
1127	! ! ! salt exchanges at the ice/ocean interface
1128	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
1129	! !
1130	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
1131	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
1132	! !!
1133	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
1134	! !! ! E-P (kg m-2 s-2)
1135	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
1136	! ENDDO !ji
1137	! ENDDO !jj!
1138	!
1139	! ENDIF !ln_seaicebal
1140	!
1141	!#endif
1142
1143	ENDIF
1144
1145	END SUBROUTINE seaice_asm_inc
1146
1147	!!======================================================================
1148	END MODULE asminc

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