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asminc.F90 in branches/2012/dev_v3_4_STABLE_2012/NEMOGCM/NEMO/OPA_SRC/ASM – NEMO

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source: branches/2012/dev_v3_4_STABLE_2012/NEMOGCM/NEMO/OPA_SRC/ASM/asminc.F90 @ 4083

Last change on this file since 4083 was 3784, checked in by gm, 11 years ago
dev_v3_4_STABLE_2012: #1046 : bug correction to compile LIM3 with ASM
Property svn:keywords set to `Id`
File size: 48.3 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 oce ! Dynamics and active tracers defined in memory
29	USE ldfdyn_oce ! ocean dynamics: lateral physics
30	USE eosbn2 ! Equation of state - in situ and potential density
31	USE zpshde ! Partial step : Horizontal Derivative
32	USE iom ! Library to read input files
33	USE asmpar ! Parameters for the assmilation interface
34	USE c1d ! 1D initialization
35	USE in_out_manager ! I/O manager
36	USE lib_mpp ! MPP library
37	#if defined key_lim2
38	USE ice_2 ! LIM2
39	#endif
40	USE sbc_oce ! Surface boundary condition variables.
41	USE domvvl
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 = .FALSE. !: 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 = 0 !: 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	#if defined key_asminc
75	REAL(wp), PUBLIC, DIMENSION(:,:), ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
76	#endif
77	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
78	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
79	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
80	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
81	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
82	!
83	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
84	! !: = 1 Linear hat-like, centred in middle of IAU interval
85	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
86
87	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
88	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
89
90	!! * Substitutions
91	# include "domzgr_substitute.h90"
92	# include "ldfdyn_substitute.h90"
93	# include "vectopt_loop_substitute.h90"
94
95	!!----------------------------------------------------------------------
96	!! NEMO/OPA 3.3 , NEMO Consortium (2010)
97	!! $Id$
98	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
99	!!----------------------------------------------------------------------
100	CONTAINS
101
102	SUBROUTINE asm_inc_init
103	!!----------------------------------------------------------------------
104	!! * ROUTINE asm_inc_init *
105	!!
106	!! ** Purpose : Initialize the assimilation increment and IAU weights.
107	!!
108	!! ** Method : Initialize the assimilation increment and IAU weights.
109	!!
110	!! ** Action :
111	!!----------------------------------------------------------------------
112	!!
113	!!
114	INTEGER :: ji,jj,jk
115	INTEGER :: jt
116	INTEGER :: imid
117	INTEGER :: inum
118	INTEGER :: iiauper ! Number of time steps in the IAU period
119	INTEGER :: icycper ! Number of time steps in the cycle
120	INTEGER :: iitend_date ! Date YYYYMMDD of final time step
121	INTEGER :: iitbkg_date ! Date YYYYMMDD of background time step for Jb term
122	INTEGER :: iitdin_date ! Date YYYYMMDD of background time step for DI
123	INTEGER :: iitiaustr_date ! Date YYYYMMDD of IAU interval start time step
124	INTEGER :: iitiaufin_date ! Date YYYYMMDD of IAU interval final time step
125
126	REAL(wp) :: znorm ! Normalization factor for IAU weights
127	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights
128	! (should be equal to one)
129	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
130	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
131	REAL(wp) :: zdate_bkg ! Date in background state file for DI
132	REAL(wp) :: zdate_inc ! Time axis in increments file
133
134	REAL(wp), POINTER, DIMENSION(:,:) :: hdiv
135	!!
136	NAMELIST/nam_asminc/ ln_bkgwri, &
137	& ln_trainc, ln_dyninc, ln_sshinc, &
138	& ln_asmdin, ln_asmiau, &
139	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
140	& ln_salfix, salfixmin, &
141	& nn_divdmp
142	!!----------------------------------------------------------------------
143
144	!-----------------------------------------------------------------------
145	! Read Namelist nam_asminc : assimilation increment interface
146	!-----------------------------------------------------------------------
147
148	! Set default values
149	ln_bkgwri = .FALSE.
150	ln_trainc = .FALSE.
151	ln_dyninc = .FALSE.
152	ln_sshinc = .FALSE.
153	ln_seaiceinc = .FALSE.
154	ln_asmdin = .FALSE.
155	ln_asmiau = .TRUE.
156	ln_salfix = .FALSE.
157	ln_temnofreeze = .FALSE.
158	salfixmin = -9999
159	nitbkg = 0
160	nitdin = 0
161	nitiaustr = 1
162	nitiaufin = 150 ! = 10 days with ORCA2
163	niaufn = 0
164
165	REWIND ( numnam )
166	READ ( numnam, nam_asminc )
167
168	! Control print
169	IF(lwp) THEN
170	WRITE(numout,*)
171	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
172	WRITE(numout,*) '~~~~~~~~~~~~'
173	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
174	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
175	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
176	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
177	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
178	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
179	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
180	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
181	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
182	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
183	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
184	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
185	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
186	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
187	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
188	ENDIF
189
190	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
191	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
192	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
193	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
194
195	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
196	icycper = nitend - nit000 + 1 ! Cycle interval length
197
198	! Date of final time step
199	CALL calc_date( nit000, nitend, ndate0, iitend_date )
200
201	! Background time for Jb referenced to ndate0
202	CALL calc_date( nit000, nitbkg_r, ndate0, iitbkg_date )
203
204	! Background time for DI referenced to ndate0
205	CALL calc_date( nit000, nitdin_r, ndate0, iitdin_date )
206
207	! IAU start time referenced to ndate0
208	CALL calc_date( nit000, nitiaustr_r, ndate0, iitiaustr_date )
209
210	! IAU end time referenced to ndate0
211	CALL calc_date( nit000, nitiaufin_r, ndate0, iitiaufin_date )
212
213	IF(lwp) THEN
214	WRITE(numout,*)
215	WRITE(numout,*) ' Time steps referenced to current cycle:'
216	WRITE(numout,*) ' iitrst = ', nit000 - 1
217	WRITE(numout,*) ' nit000 = ', nit000
218	WRITE(numout,*) ' nitend = ', nitend
219	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
220	WRITE(numout,*) ' nitdin_r = ', nitdin_r
221	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
222	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
223	WRITE(numout,*)
224	WRITE(numout,*) ' Dates referenced to current cycle:'
225	WRITE(numout,*) ' ndastp = ', ndastp
226	WRITE(numout,*) ' ndate0 = ', ndate0
227	WRITE(numout,*) ' iitend_date = ', iitend_date
228	WRITE(numout,*) ' iitbkg_date = ', iitbkg_date
229	WRITE(numout,*) ' iitdin_date = ', iitdin_date
230	WRITE(numout,*) ' iitiaustr_date = ', iitiaustr_date
231	WRITE(numout,*) ' iitiaufin_date = ', iitiaufin_date
232	ENDIF
233
234	IF ( nacc /= 0 ) &
235	& CALL ctl_stop( ' nacc /= 0 and key_asminc :', &
236	& ' Assimilation increments have only been implemented', &
237	& ' for synchronous time stepping' )
238
239	IF ( ( ln_asmdin ).AND.( ln_asmiau ) ) &
240	& CALL ctl_stop( ' ln_asmdin and ln_asmiau :', &
241	& ' Choose Direct Initialization OR Incremental Analysis Updating')
242
243	IF ( ( ( .NOT. ln_asmdin ).AND.( .NOT. ln_asmiau ) ) &
244	.AND.( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ) .OR. ( ln_seaiceinc) )) &
245	& CALL ctl_stop( ' One or more of ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc is set to .true.', &
246	& ' but ln_asmdin and ln_asmiau are both set to .false. :', &
247	& ' Inconsistent options')
248
249	IF ( ( ln_bkgwri ).AND.( ( ln_asmdin ).OR.( ln_asmiau ) ) ) &
250	& CALL ctl_stop( ' ln_bkgwri and either ln_asmdin or ln_asmiau are set to .true.:', &
251	& ' The background state must be written before applying the increments')
252
253	IF ( ( niaufn /= 0 ).AND.( niaufn /= 1 ) ) &
254	& CALL ctl_stop( ' niaufn /= 0 or niaufn /=1 :', &
255	& ' Type IAU weighting function is invalid')
256
257	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ).AND.( .NOT. ln_seaiceinc ) &
258	& ) &
259	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc are set to .false. :', &
260	& ' The assimilation increments are not applied')
261
262	IF ( ( ln_asmiau ).AND.( nitiaustr == nitiaufin ) ) &
263	& CALL ctl_stop( ' nitiaustr = nitiaufin :', &
264	& ' IAU interval is of zero length')
265
266	IF ( ( ln_asmiau ).AND.( ( nitiaustr_r < nit000 ).OR.( nitiaufin_r > nitend ) ) ) &
267	& CALL ctl_stop( ' nitiaustr or nitiaufin :', &
268	& ' IAU starting or final time step is outside the cycle interval', &
269	& ' Valid range nit000 to nitend')
270
271	IF ( ( nitbkg_r < nit000 - 1 ).OR.( nitbkg_r > nitend ) ) &
272	& CALL ctl_stop( ' nitbkg :', &
273	& ' Background time step is outside the cycle interval')
274
275	IF ( ( nitdin_r < nit000 - 1 ).OR.( nitdin_r > nitend ) ) &
276	& CALL ctl_stop( ' nitdin :', &
277	& ' Background time step for Direct Initialization is outside', &
278	& ' the cycle interval')
279
280	IF ( nstop > 0 ) RETURN ! if there are any errors then go no further
281
282	!--------------------------------------------------------------------
283	! Initialize the Incremental Analysis Updating weighting function
284	!--------------------------------------------------------------------
285
286	IF ( ln_asmiau ) THEN
287
288	ALLOCATE( wgtiau( icycper ) )
289
290	wgtiau(:) = 0.0
291
292	IF ( niaufn == 0 ) THEN
293
294	!---------------------------------------------------------
295	! Constant IAU forcing
296	!---------------------------------------------------------
297
298	DO jt = 1, iiauper
299	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
300	END DO
301
302	ELSEIF ( niaufn == 1 ) THEN
303
304	!---------------------------------------------------------
305	! Linear hat-like, centred in middle of IAU interval
306	!---------------------------------------------------------
307
308	! Compute the normalization factor
309	znorm = 0.0
310	IF ( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
311	imid = iiauper / 2
312	DO jt = 1, imid
313	znorm = znorm + REAL( jt )
314	END DO
315	znorm = 2.0 * znorm
316	ELSE ! Odd number of time steps in IAU interval
317	imid = ( iiauper + 1 ) / 2
318	DO jt = 1, imid - 1
319	znorm = znorm + REAL( jt )
320	END DO
321	znorm = 2.0 * znorm + REAL( imid )
322	ENDIF
323	znorm = 1.0 / znorm
324
325	DO jt = 1, imid - 1
326	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
327	END DO
328	DO jt = imid, iiauper
329	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
330	END DO
331
332	ENDIF
333
334	! Test that the integral of the weights over the weighting interval equals 1
335	IF(lwp) THEN
336	WRITE(numout,*)
337	WRITE(numout,*) 'asm_inc_init : IAU weights'
338	WRITE(numout,*) '~~~~~~~~~~~~'
339	WRITE(numout,*) ' time step IAU weight'
340	WRITE(numout,*) ' ========= ====================='
341	ztotwgt = 0.0
342	DO jt = 1, icycper
343	ztotwgt = ztotwgt + wgtiau(jt)
344	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
345	END DO
346	WRITE(numout,*) ' ==================================='
347	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
348	WRITE(numout,*) ' ==================================='
349	ENDIF
350
351	ENDIF
352
353	!--------------------------------------------------------------------
354	! Allocate and initialize the increment arrays
355	!--------------------------------------------------------------------
356
357	ALLOCATE( t_bkginc(jpi,jpj,jpk) )
358	ALLOCATE( s_bkginc(jpi,jpj,jpk) )
359	ALLOCATE( u_bkginc(jpi,jpj,jpk) )
360	ALLOCATE( v_bkginc(jpi,jpj,jpk) )
361	ALLOCATE( ssh_bkginc(jpi,jpj) )
362	ALLOCATE( seaice_bkginc(jpi,jpj))
363	#if defined key_asminc
364	ALLOCATE( ssh_iau(jpi,jpj) )
365	#endif
366	t_bkginc(:,:,:) = 0.0
367	s_bkginc(:,:,:) = 0.0
368	u_bkginc(:,:,:) = 0.0
369	v_bkginc(:,:,:) = 0.0
370	ssh_bkginc(:,:) = 0.0
371	seaice_bkginc(:,:) = 0.0
372	#if defined key_asminc
373	ssh_iau(:,:) = 0.0
374	#endif
375	IF ( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ).OR.( ln_seaiceinc ) ) THEN
376
377	!--------------------------------------------------------------------
378	! Read the increments from file
379	!--------------------------------------------------------------------
380
381	CALL iom_open( c_asminc, inum )
382
383	CALL iom_get( inum, 'time', zdate_inc )
384
385	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
386	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
387	z_inc_dateb = zdate_inc
388	z_inc_datef = zdate_inc
389
390	IF(lwp) THEN
391	WRITE(numout,*)
392	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid ', &
393	& ' between dates ', NINT( z_inc_dateb ),' and ', &
394	& NINT( z_inc_datef )
395	WRITE(numout,*) '~~~~~~~~~~~~'
396	ENDIF
397
398	IF ( ( NINT( z_inc_dateb ) < ndastp ) &
399	& .OR.( NINT( z_inc_datef ) > iitend_date ) ) &
400	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
401	& ' outside the assimilation interval' )
402
403	IF ( ( ln_asmdin ).AND.( NINT( zdate_inc ) /= iitdin_date ) ) &
404	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
405	& ' not agree with Direct Initialization time' )
406
407	IF ( ln_trainc ) THEN
408	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
409	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
410	! Apply the masks
411	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
412	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
413	! Set missing increments to 0.0 rather than 1e+20
414	! to allow for differences in masks
415	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
416	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
417	ENDIF
418
419	IF ( ln_dyninc ) THEN
420	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
421	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
422	! Apply the masks
423	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
424	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
425	! Set missing increments to 0.0 rather than 1e+20
426	! to allow for differences in masks
427	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
428	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
429	ENDIF
430
431	IF ( ln_sshinc ) THEN
432	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
433	! Apply the masks
434	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
435	! Set missing increments to 0.0 rather than 1e+20
436	! to allow for differences in masks
437	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
438	ENDIF
439
440	IF ( ln_seaiceinc ) THEN
441	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
442	! Apply the masks
443	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
444	! Set missing increments to 0.0 rather than 1e+20
445	! to allow for differences in masks
446	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
447	ENDIF
448
449	CALL iom_close( inum )
450
451	ENDIF
452
453	!-----------------------------------------------------------------------
454	! Apply divergence damping filter
455	!-----------------------------------------------------------------------
456
457	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN
458
459	CALL wrk_alloc(jpi,jpj,hdiv)
460
461	DO jt = 1, nn_divdmp
462
463	DO jk = 1, jpkm1
464
465	hdiv(:,:) = 0._wp
466
467	DO jj = 2, jpjm1
468	DO ji = fs_2, fs_jpim1 ! vector opt.
469	hdiv(ji,jj) = &
470	( e2u(ji ,jj ) * fse3u(ji ,jj ,jk) * u_bkginc(ji ,jj ,jk) &
471	- e2u(ji-1,jj ) * fse3u(ji-1,jj ,jk) * u_bkginc(ji-1,jj ,jk) &
472	+ e1v(ji ,jj ) * fse3v(ji ,jj ,jk) * v_bkginc(ji ,jj ,jk) &
473	- e1v(ji ,jj-1) * fse3v(ji ,jj-1,jk) * v_bkginc(ji ,jj-1,jk) ) &
474	/ ( e1t(ji,jj) * e2t(ji,jj) * fse3t(ji,jj,jk) )
475	END DO
476	END DO
477
478	CALL lbc_lnk( hdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
479
480	DO jj = 2, jpjm1
481	DO ji = fs_2, fs_jpim1 ! vector opt.
482	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) &
483	- e1t(ji ,jj)e2t(ji ,jj) hdiv(ji ,jj) ) &
484	/ e1u(ji,jj) * umask(ji,jj,jk)
485	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) &
486	- e1t(ji,jj )e2t(ji,jj ) hdiv(ji,jj ) ) &
487	/ e2v(ji,jj) * vmask(ji,jj,jk)
488	END DO
489	END DO
490
491	END DO
492
493	END DO
494
495	CALL wrk_dealloc(jpi,jpj,hdiv)
496
497	ENDIF
498
499
500
501	!-----------------------------------------------------------------------
502	! Allocate and initialize the background state arrays
503	!-----------------------------------------------------------------------
504
505	IF ( ln_asmdin ) THEN
506
507	ALLOCATE( t_bkg(jpi,jpj,jpk) )
508	ALLOCATE( s_bkg(jpi,jpj,jpk) )
509	ALLOCATE( u_bkg(jpi,jpj,jpk) )
510	ALLOCATE( v_bkg(jpi,jpj,jpk) )
511	ALLOCATE( ssh_bkg(jpi,jpj) )
512
513	t_bkg(:,:,:) = 0.0
514	s_bkg(:,:,:) = 0.0
515	u_bkg(:,:,:) = 0.0
516	v_bkg(:,:,:) = 0.0
517	ssh_bkg(:,:) = 0.0
518
519	!--------------------------------------------------------------------
520	! Read from file the background state at analysis time
521	!--------------------------------------------------------------------
522
523	CALL iom_open( c_asmdin, inum )
524
525	CALL iom_get( inum, 'rdastp', zdate_bkg )
526
527	IF(lwp) THEN
528	WRITE(numout,*)
529	WRITE(numout,*) 'asm_inc_init : Assimilation background state valid at : ', &
530	& NINT( zdate_bkg )
531	WRITE(numout,*) '~~~~~~~~~~~~'
532	ENDIF
533
534	IF ( NINT( zdate_bkg ) /= iitdin_date ) &
535	& CALL ctl_warn( ' Validity time of assimilation background state does', &
536	& ' not agree with Direct Initialization time' )
537
538	IF ( ln_trainc ) THEN
539	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
540	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
541	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
542	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
543	ENDIF
544
545	IF ( ln_dyninc ) THEN
546	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
547	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
548	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
549	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
550	ENDIF
551
552	IF ( ln_sshinc ) THEN
553	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
554	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
555	ENDIF
556
557	CALL iom_close( inum )
558
559	ENDIF
560	!
561	END SUBROUTINE asm_inc_init
562
563
564	SUBROUTINE calc_date( kit000, kt, kdate0, kdate )
565	!!----------------------------------------------------------------------
566	!! * ROUTINE calc_date *
567	!!
568	!! ** Purpose : Compute the calendar date YYYYMMDD at a given time step.
569	!!
570	!! ** Method : Compute the calendar date YYYYMMDD at a given time step.
571	!!
572	!! ** Action :
573	!!----------------------------------------------------------------------
574	INTEGER, INTENT(IN) :: kit000 ! Initial time step
575	INTEGER, INTENT(IN) :: kt ! Current time step referenced to kit000
576	INTEGER, INTENT(IN) :: kdate0 ! Initial date
577	INTEGER, INTENT(OUT) :: kdate ! Current date reference to kdate0
578	!
579	INTEGER :: iyea0 ! Initial year
580	INTEGER :: imon0 ! Initial month
581	INTEGER :: iday0 ! Initial day
582	INTEGER :: iyea ! Current year
583	INTEGER :: imon ! Current month
584	INTEGER :: iday ! Current day
585	INTEGER :: idaystp ! Number of days between initial and current date
586	INTEGER :: idaycnt ! Day counter
587
588	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
589
590	!-----------------------------------------------------------------------
591	! Compute the calendar date YYYYMMDD
592	!-----------------------------------------------------------------------
593
594	! Initial date
595	iyea0 = kdate0 / 10000
596	imon0 = ( kdate0 - ( iyea0 * 10000 ) ) / 100
597	iday0 = kdate0 - ( iyea0 * 10000 ) - ( imon0 * 100 )
598
599	! Check that kt >= kit000 - 1
600	IF ( kt < kit000 - 1 ) CALL ctl_stop( ' kt must be >= kit000 - 1')
601
602	! If kt = kit000 - 1 then set the date to the restart date
603	IF ( kt == kit000 - 1 ) THEN
604
605	kdate = ndastp
606	RETURN
607
608	ENDIF
609
610	! Compute the number of days from the initial date
611	idaystp = INT( REAL( kt - kit000 ) * rdt / 86400. )
612
613	iday = iday0
614	imon = imon0
615	iyea = iyea0
616	idaycnt = 0
617
618	CALL calc_month_len( iyea, imonth_len )
619
620	DO WHILE ( idaycnt < idaystp )
621	iday = iday + 1
622	IF ( iday > imonth_len(imon) ) THEN
623	iday = 1
624	imon = imon + 1
625	ENDIF
626	IF ( imon > 12 ) THEN
627	imon = 1
628	iyea = iyea + 1
629	CALL calc_month_len( iyea, imonth_len ) ! update month lengths
630	ENDIF
631	idaycnt = idaycnt + 1
632	END DO
633	!
634	kdate = iyea * 10000 + imon * 100 + iday
635	!
636	END SUBROUTINE
637
638
639	SUBROUTINE calc_month_len( iyear, imonth_len )
640	!!----------------------------------------------------------------------
641	!! * ROUTINE calc_month_len *
642	!!
643	!! ** Purpose : Compute the number of days in a months given a year.
644	!!
645	!! ** Method :
646	!!----------------------------------------------------------------------
647	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
648	INTEGER :: iyear !: year
649	!!----------------------------------------------------------------------
650	!
651	! length of the month of the current year (from nleapy, read in namelist)
652	IF ( nleapy < 2 ) THEN
653	imonth_len(:) = (/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
654	IF ( nleapy == 1 ) THEN ! we are using calendar with leap years
655	IF ( MOD(iyear, 4) == 0 .AND. ( MOD(iyear, 400) == 0 .OR. MOD(iyear, 100) /= 0 ) ) THEN
656	imonth_len(2) = 29
657	ENDIF
658	ENDIF
659	ELSE
660	imonth_len(:) = nleapy ! all months with nleapy days per year
661	ENDIF
662	!
663	END SUBROUTINE
664
665
666	SUBROUTINE tra_asm_inc( kt )
667	!!----------------------------------------------------------------------
668	!! * ROUTINE tra_asm_inc *
669	!!
670	!! ** Purpose : Apply the tracer (T and S) assimilation increments
671	!!
672	!! ** Method : Direct initialization or Incremental Analysis Updating
673	!!
674	!! ** Action :
675	!!----------------------------------------------------------------------
676	INTEGER, INTENT(IN) :: kt ! Current time step
677	!
678	INTEGER :: ji,jj,jk
679	INTEGER :: it
680	REAL(wp) :: zincwgt ! IAU weight for current time step
681	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
682	!!----------------------------------------------------------------------
683
684	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
685	! used to prevent the applied increments taking the temperature below the local freezing point
686
687	#if defined key_cice
688	fzptnz(:,:,:) = -1.8_wp
689	#else
690	DO jk = 1, jpk
691	DO jj = 1, jpj
692	DO ji = 1, jpk
693	fzptnz (ji,jj,jk) = ( -0.0575_wp + 1.710523e-3_wp * SQRT( tsn(ji,jj,jk,jp_sal) ) &
694	- 2.154996e-4_wp * tsn(ji,jj,jk,jp_sal) ) * tsn(ji,jj,jk,jp_sal) &
695	- 7.53e-4_wp * fsdepw(ji,jj,jk) ! (pressure in dbar)
696	END DO
697	END DO
698	END DO
699	#endif
700
701	IF ( ln_asmiau ) THEN
702
703	!--------------------------------------------------------------------
704	! Incremental Analysis Updating
705	!--------------------------------------------------------------------
706
707	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
708
709	it = kt - nit000 + 1
710	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
711
712	IF(lwp) THEN
713	WRITE(numout,*)
714	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', &
715	& kt,' with IAU weight = ', wgtiau(it)
716	WRITE(numout,*) '~~~~~~~~~~~~'
717	ENDIF
718
719	! Update the tracer tendencies
720	DO jk = 1, jpkm1
721	IF (ln_temnofreeze) THEN
722	! Do not apply negative increments if the temperature will fall below freezing
723	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
724	& tsn(:,:,jk,jp_tem) + tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
725	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
726	END WHERE
727	ELSE
728	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
729	ENDIF
730	IF (ln_salfix) THEN
731	! Do not apply negative increments if the salinity will fall below a specified
732	! minimum value salfixmin
733	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
734	& tsn(:,:,jk,jp_sal) + tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
735	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
736	END WHERE
737	ELSE
738	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
739	ENDIF
740	END DO
741
742	ENDIF
743
744	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
745	DEALLOCATE( t_bkginc )
746	DEALLOCATE( s_bkginc )
747	ENDIF
748
749
750	ELSEIF ( ln_asmdin ) THEN
751
752	!--------------------------------------------------------------------
753	! Direct Initialization
754	!--------------------------------------------------------------------
755
756	IF ( kt == nitdin_r ) THEN
757
758	neuler = 0 ! Force Euler forward step
759
760	! Initialize the now fields with the background + increment
761	IF (ln_temnofreeze) THEN
762	! Do not apply negative increments if the temperature will fall below freezing
763	WHERE(t_bkginc(:,:,:) > 0.0_wp .OR. &
764	& tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
765	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
766	END WHERE
767	ELSE
768	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
769	ENDIF
770	IF (ln_salfix) THEN
771	! Do not apply negative increments if the salinity will fall below a specified
772	! minimum value salfixmin
773	WHERE(s_bkginc(:,:,:) > 0.0_wp .OR. &
774	& tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
775	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
776	END WHERE
777	ELSE
778	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
779	ENDIF
780
781	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
782
783	CALL eos( tsb, rhd, rhop ) ! Before potential and in situ densities
784
785	IF( ln_zps .AND. .NOT. lk_c1d ) &
786	& CALL zps_hde( nit000, jpts, tsb, & ! Partial steps: before horizontal derivative
787	& gtsu, gtsv, rhd, & ! of T, S, rd at the bottom ocean level
788	& gru , grv )
789
790	#if defined key_zdfkpp
791	CALL eos( tsn, rhd ) ! Compute rhd
792	#endif
793
794	DEALLOCATE( t_bkginc )
795	DEALLOCATE( s_bkginc )
796	DEALLOCATE( t_bkg )
797	DEALLOCATE( s_bkg )
798	ENDIF
799	!
800	ENDIF
801	! Perhaps the following call should be in step
802	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
803	!
804	END SUBROUTINE tra_asm_inc
805
806
807	SUBROUTINE dyn_asm_inc( kt )
808	!!----------------------------------------------------------------------
809	!! * ROUTINE dyn_asm_inc *
810	!!
811	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
812	!!
813	!! ** Method : Direct initialization or Incremental Analysis Updating.
814	!!
815	!! ** Action :
816	!!----------------------------------------------------------------------
817	INTEGER, INTENT(IN) :: kt ! Current time step
818	!
819	INTEGER :: jk
820	INTEGER :: it
821	REAL(wp) :: zincwgt ! IAU weight for current time step
822	!!----------------------------------------------------------------------
823
824	IF ( ln_asmiau ) THEN
825
826	!--------------------------------------------------------------------
827	! Incremental Analysis Updating
828	!--------------------------------------------------------------------
829
830	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
831
832	it = kt - nit000 + 1
833	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
834
835	IF(lwp) THEN
836	WRITE(numout,*)
837	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', &
838	& kt,' with IAU weight = ', wgtiau(it)
839	WRITE(numout,*) '~~~~~~~~~~~~'
840	ENDIF
841
842	! Update the dynamic tendencies
843	DO jk = 1, jpkm1
844	ua(:,:,jk) = ua(:,:,jk) + u_bkginc(:,:,jk) * zincwgt
845	va(:,:,jk) = va(:,:,jk) + v_bkginc(:,:,jk) * zincwgt
846	END DO
847
848	IF ( kt == nitiaufin_r ) THEN
849	DEALLOCATE( u_bkginc )
850	DEALLOCATE( v_bkginc )
851	ENDIF
852
853	ENDIF
854
855	ELSEIF ( ln_asmdin ) THEN
856
857	!--------------------------------------------------------------------
858	! Direct Initialization
859	!--------------------------------------------------------------------
860
861	IF ( kt == nitdin_r ) THEN
862
863	neuler = 0 ! Force Euler forward step
864
865	! Initialize the now fields with the background + increment
866	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
867	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
868
869	ub(:,:,:) = un(:,:,:) ! Update before fields
870	vb(:,:,:) = vn(:,:,:)
871
872	DEALLOCATE( u_bkg )
873	DEALLOCATE( v_bkg )
874	DEALLOCATE( u_bkginc )
875	DEALLOCATE( v_bkginc )
876	ENDIF
877	!
878	ENDIF
879	!
880	END SUBROUTINE dyn_asm_inc
881
882
883	SUBROUTINE ssh_asm_inc( kt )
884	!!----------------------------------------------------------------------
885	!! * ROUTINE ssh_asm_inc *
886	!!
887	!! ** Purpose : Apply the sea surface height assimilation increment.
888	!!
889	!! ** Method : Direct initialization or Incremental Analysis Updating.
890	!!
891	!! ** Action :
892	!!----------------------------------------------------------------------
893	INTEGER, INTENT(IN) :: kt ! Current time step
894	!
895	INTEGER :: it
896	INTEGER :: jk
897	REAL(wp) :: zincwgt ! IAU weight for current time step
898	!!----------------------------------------------------------------------
899
900	IF ( ln_asmiau ) THEN
901
902	!--------------------------------------------------------------------
903	! Incremental Analysis Updating
904	!--------------------------------------------------------------------
905
906	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
907
908	it = kt - nit000 + 1
909	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
910
911	IF(lwp) THEN
912	WRITE(numout,*)
913	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
914	& kt,' with IAU weight = ', wgtiau(it)
915	WRITE(numout,*) '~~~~~~~~~~~~'
916	ENDIF
917
918	! Save the tendency associated with the IAU weighted SSH increment
919	! (applied in dynspg.*)
920	#if defined key_asminc
921	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
922	#endif
923	IF ( kt == nitiaufin_r ) THEN
924	DEALLOCATE( ssh_bkginc )
925	ENDIF
926
927	ENDIF
928
929	ELSEIF ( ln_asmdin ) THEN
930
931	!--------------------------------------------------------------------
932	! Direct Initialization
933	!--------------------------------------------------------------------
934
935	IF ( kt == nitdin_r ) THEN
936
937	neuler = 0 ! Force Euler forward step
938
939	! Initialize the now fields the background + increment
940	sshn(:,:) = ssh_bkg(:,:) + ssh_bkginc(:,:)
941
942	! Update before fields
943	sshb(:,:) = sshn(:,:)
944
945	IF( lk_vvl ) THEN
946	DO jk = 1, jpk
947	fse3t_b(:,:,jk) = fse3t_n(:,:,jk)
948	END DO
949	ENDIF
950
951	DEALLOCATE( ssh_bkg )
952	DEALLOCATE( ssh_bkginc )
953
954	ENDIF
955	!
956	ENDIF
957	!
958	END SUBROUTINE ssh_asm_inc
959
960	SUBROUTINE seaice_asm_inc( kt, kindic )
961	!!----------------------------------------------------------------------
962	!! * ROUTINE seaice_asm_inc *
963	!!
964	!! ** Purpose : Apply the sea ice assimilation increment.
965	!!
966	!! ** Method : Direct initialization or Incremental Analysis Updating.
967	!!
968	!! ** Action :
969	!!
970	!! History :
971	!! ! 07-2011 (D. Lea) Initial version based on ssh_asm_inc
972	!!----------------------------------------------------------------------
973
974	IMPLICIT NONE
975
976	!! * Arguments
977	INTEGER, INTENT(IN) :: kt ! Current time step
978	INTEGER, OPTIONAL, INTENT(IN) :: kindic ! flag for disabling the deallocation
979
980	!! * Local declarations
981	INTEGER :: it
982	REAL(wp) :: zincwgt ! IAU weight for current time step
983
984	#if defined key_lim2
985	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
986	REAL(wp) :: zhicifmin=0.5_wp ! ice minimum depth in metres
987
988	#endif
989
990
991	IF ( ln_asmiau ) THEN
992
993	!--------------------------------------------------------------------
994	! Incremental Analysis Updating
995	!--------------------------------------------------------------------
996
997	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
998
999	it = kt - nit000 + 1
1000	zincwgt = wgtiau(it) ! IAU weight for the current time step
1001	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
1002
1003	IF(lwp) THEN
1004	WRITE(numout,*)
1005	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', &
1006	& kt,' with IAU weight = ', wgtiau(it)
1007	WRITE(numout,*) '~~~~~~~~~~~~'
1008	ENDIF
1009
1010	#if defined key_lim2
1011
1012	zofrld(:,:)=frld(:,:)
1013	zohicif(:,:)=hicif(:,:)
1014
1015	frld = MIN( MAX( frld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1016	pfrld = MIN( MAX( pfrld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1017	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1018
1019	zseaicendg(:,:)=zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1020
1021	! Nudge sea ice depth to bring it up to a required minimum depth
1022
1023	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1024	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1025	ELSEWHERE
1026	zhicifinc(:,:) = 0.0_wp
1027	END WHERE
1028
1029	! nudge ice depth
1030	hicif(:,:)=hicif(:,:) + zhicifinc(:,:)
1031	phicif(:,:)=phicif(:,:) + zhicifinc(:,:)
1032
1033	! seaice salinity balancing (to add)
1034
1035	#endif
1036
1037	#if defined key_cice
1038
1039	! Pass ice increment tendency into CICE
1040	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
1041
1042	#endif
1043
1044	IF ( kt == nitiaufin_r ) THEN
1045	DEALLOCATE( seaice_bkginc )
1046	ENDIF
1047
1048	ELSE
1049
1050	#if defined key_cice
1051
1052	! Zero ice increment tendency into CICE
1053	ndaice_da(:,:) = 0.0_wp
1054
1055	#endif
1056
1057	ENDIF
1058
1059	ELSEIF ( ln_asmdin ) THEN
1060
1061	!--------------------------------------------------------------------
1062	! Direct Initialization
1063	!--------------------------------------------------------------------
1064
1065	IF ( kt == nitdin_r ) THEN
1066
1067	neuler = 0 ! Force Euler forward step
1068
1069	#if defined key_lim2
1070
1071	zofrld(:,:)=frld(:,:)
1072	zohicif(:,:)=hicif(:,:)
1073
1074	! Initialize the now fields the background + increment
1075
1076	frld(:,:) = MIN( MAX( frld(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
1077	pfrld(:,:) = frld(:,:)
1078	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1079
1080	zseaicendg(:,:)=zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1081
1082	! Nudge sea ice depth to bring it up to a required minimum depth
1083
1084	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1085	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1086	ELSEWHERE
1087	zhicifinc(:,:) = 0.0_wp
1088	END WHERE
1089
1090	! nudge ice depth
1091	hicif(:,:)=hicif(:,:) + zhicifinc(:,:)
1092	phicif(:,:)=phicif(:,:)
1093
1094	! seaice salinity balancing (to add)
1095
1096	#endif
1097
1098	#if defined key_cice
1099
1100	! Pass ice increment tendency into CICE - is this correct?
1101	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
1102
1103	#endif
1104	IF ( .NOT. PRESENT(kindic) ) THEN
1105	DEALLOCATE( seaice_bkginc )
1106	END IF
1107
1108	ELSE
1109
1110	#if defined key_cice
1111
1112	! Zero ice increment tendency into CICE
1113	ndaice_da(:,:) = 0.0_wp
1114
1115	#endif
1116
1117	ENDIF
1118
1119	!#if defined key_lim2 \|\| defined key_cice
1120	!
1121	! IF (ln_seaicebal ) THEN
1122	! !! balancing salinity increments
1123	! !! simple case from limflx.F90 (doesn't include a mass flux)
1124	! !! assumption is that as ice concentration is reduced or increased
1125	! !! the snow and ice depths remain constant
1126	! !! note that snow is being created where ice concentration is being increased
1127	! !! - could be more sophisticated and
1128	! !! not do this (but would need to alter h_snow)
1129	!
1130	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
1131	!
1132	! DO jj = 1, jpj
1133	! DO ji = 1, jpi
1134	! ! calculate change in ice and snow mass per unit area
1135	! ! positive values imply adding salt to the ocean (results from ice formation)
1136	! ! fwf : ice formation and melting
1137	!
1138	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
1139	!
1140	! ! change salinity down to mixed layer depth
1141	! mld=hmld_kara(ji,jj)
1142	!
1143	! ! prevent small mld
1144	! ! less than 10m can cause salinity instability
1145	! IF (mld < 10) mld=10
1146	!
1147	! ! set to bottom of a level
1148	! DO jk = jpk-1, 2, -1
1149	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
1150	! mld=gdepw(ji,jj,jk+1)
1151	! jkmax=jk
1152	! ENDIF
1153	! ENDDO
1154	!
1155	! ! avoid applying salinity balancing in shallow water or on land
1156	! !
1157	!
1158	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
1159	!
1160	! dsal_ocn=0.0_wp
1161	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
1162	!
1163	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
1164	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
1165	!
1166	! ! put increments in for levels in the mixed layer
1167	! ! but prevent salinity below a threshold value
1168	!
1169	! DO jk = 1, jkmax
1170	!
1171	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
1172	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
1173	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
1174	! ENDIF
1175	!
1176	! ENDDO
1177	!
1178	! ! ! salt exchanges at the ice/ocean interface
1179	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
1180	! !
1181	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
1182	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
1183	! !!
1184	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
1185	! !! ! E-P (kg m-2 s-2)
1186	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
1187	! ENDDO !ji
1188	! ENDDO !jj!
1189	!
1190	! ENDIF !ln_seaicebal
1191	!
1192	!#endif
1193
1194
1195	ENDIF
1196
1197	END SUBROUTINE seaice_asm_inc
1198	!!======================================================================
1199	END MODULE asminc

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