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asminc.F90 in branches/UKMO/dev_r5518_v3.4_asm_nemovar_community/NEMOGCM/NEMO/OPA_SRC/ASM – NEMO

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source: branches/UKMO/dev_r5518_v3.4_asm_nemovar_community/NEMOGCM/NEMO/OPA_SRC/ASM/asminc.F90 @ 6630

Last change on this file since 6630 was 6630, checked in by kingr, 8 years ago
Adpated changes required to apply 2D surft increments in AMM7 from NEMO3.4 branch /branches/dev/frwe/vn3.4_ASM_NEMOVAR_community.
File size: 52.5 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	USE zdfmxl, ONLY : &
43	& hmld_tref, &
44	#if defined key_karaml
45	& hmld_kara, &
46	& ln_kara, &
47	#endif
48	& hmld, &
49	& hmlp, &
50	& hmlpt
51	#if defined key_bdy
52	USE bdy_oce, ONLY: bdytmask
53	#endif
54
55	IMPLICIT NONE
56	PRIVATE
57
58	PUBLIC asm_inc_init !: Initialize the increment arrays and IAU weights
59	PUBLIC calc_date !: Compute the calendar date YYYYMMDD on a given step
60	PUBLIC tra_asm_inc !: Apply the tracer (T and S) increments
61	PUBLIC dyn_asm_inc !: Apply the dynamic (u and v) increments
62	PUBLIC ssh_asm_inc !: Apply the SSH increment
63	PUBLIC seaice_asm_inc !: Apply the seaice increment
64
65	#if defined key_asminc
66	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
67	#else
68	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
69	#endif
70	LOGICAL, PUBLIC :: ln_bkgwri = .FALSE. !: No output of the background state fields
71	LOGICAL, PUBLIC :: ln_asmiau = .FALSE. !: No applying forcing with an assimilation increment
72	LOGICAL, PUBLIC :: ln_asmdin = .FALSE. !: No direct initialization
73	LOGICAL, PUBLIC :: ln_trainc = .FALSE. !: No tracer (T and S) assimilation increments
74	LOGICAL, PUBLIC :: ln_dyninc = .FALSE. !: No dynamics (u and v) assimilation increments
75	LOGICAL, PUBLIC :: ln_sshinc = .FALSE. !: No sea surface height assimilation increment
76	LOGICAL, PUBLIC :: ln_seaiceinc !: No sea ice concentration increment
77	LOGICAL, PUBLIC :: ln_salfix = .FALSE. !: Apply minimum salinity check
78	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
79	INTEGER, PUBLIC :: nn_divdmp !: Apply divergence damping filter nn_divdmp times
80
81	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkg , s_bkg !: Background temperature and salinity
82	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkg , v_bkg !: Background u- & v- velocity components
83	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkginc, s_bkginc !: Increment to the background T & S
84	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkginc, v_bkginc !: Increment to the u- & v-components
85	REAL(wp), PUBLIC, DIMENSION(:) , ALLOCATABLE :: wgtiau !: IAU weights for each time step
86	#if defined key_asminc
87	REAL(wp), PUBLIC, DIMENSION(:,:), ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
88	#endif
89	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
90	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
91	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
92	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
93	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
94	!
95	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
96	! !: = 1 Linear hat-like, centred in middle of IAU interval
97	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
98
99	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
100	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
101
102	INTEGER :: mld_choice = 4 !: choice of mld criteria to use for physics assimilation
103	!: 1) hmld - Turbocline/mixing depth [W points]
104	!: 2) hmlp - Density criterion (0.01 kg/m^3 change from 10m) [W points]
105	!: 3) hmld_kara - Kara MLD [Interpolated]
106	!: 4) hmld_tref - Temperature criterion (0.2 K change from surface) [T points]
107
108
109	!! * Substitutions
110	# include "domzgr_substitute.h90"
111	# include "ldfdyn_substitute.h90"
112	# include "vectopt_loop_substitute.h90"
113	!!----------------------------------------------------------------------
114	!! NEMO/OPA 3.3 , NEMO Consortium (2010)
115	!! $Id$
116	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
117	!!----------------------------------------------------------------------
118	CONTAINS
119
120	SUBROUTINE asm_inc_init
121	!!----------------------------------------------------------------------
122	!! * ROUTINE asm_inc_init *
123	!!
124	!! ** Purpose : Initialize the assimilation increment and IAU weights.
125	!!
126	!! ** Method : Initialize the assimilation increment and IAU weights.
127	!!
128	!! ** Action :
129	!!----------------------------------------------------------------------
130	INTEGER :: ji, jj, jk, jt ! dummy loop indices
131	INTEGER :: imid, inum ! local integers
132	INTEGER :: ios ! Local integer output status for namelist read
133	INTEGER :: iiauper ! Number of time steps in the IAU period
134	INTEGER :: icycper ! Number of time steps in the cycle
135	INTEGER :: iitend_date ! Date YYYYMMDD of final time step
136	INTEGER :: iitbkg_date ! Date YYYYMMDD of background time step for Jb term
137	INTEGER :: iitdin_date ! Date YYYYMMDD of background time step for DI
138	INTEGER :: iitiaustr_date ! Date YYYYMMDD of IAU interval start time step
139	INTEGER :: iitiaufin_date ! Date YYYYMMDD of IAU interval final time step
140	!
141	REAL(wp) :: znorm ! Normalization factor for IAU weights
142	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights (should be equal to one)
143	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
144	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
145	REAL(wp) :: zdate_bkg ! Date in background state file for DI
146	REAL(wp) :: zdate_inc ! Time axis in increments file
147	!
148	REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: &
149	& t_bkginc_2d ! file for reading in 2D
150	! ! temperature increments
151	REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: &
152	& z_mld ! Mixed layer depth
153
154	REAL(wp), POINTER, DIMENSION(:,:) :: hdiv ! 2D workspace
155	!!
156	NAMELIST/nam_asminc/ ln_bkgwri, &
157	& ln_trainc, ln_dyninc, ln_sshinc, &
158	& ln_asmdin, ln_asmiau, &
159	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
160	& ln_salfix, salfixmin, nn_divdmp, mld_choice
161	!!----------------------------------------------------------------------
162
163	!-----------------------------------------------------------------------
164	! Read Namelist nam_asminc : assimilation increment interface
165	!-----------------------------------------------------------------------
166
167	! Set default values
168	ln_bkgwri = .FALSE.
169	ln_trainc = .FALSE.
170	ln_dyninc = .FALSE.
171	ln_sshinc = .FALSE.
172	ln_seaiceinc = .FALSE.
173	ln_asmdin = .FALSE.
174	ln_asmiau = .TRUE.
175	ln_salfix = .FALSE.
176	ln_temnofreeze = .FALSE.
177	salfixmin = -9999
178	nitbkg = 0
179	nitdin = 0
180	nitiaustr = 1
181	nitiaufin = 150
182	niaufn = 0
183
184	REWIND( numnam_ref ) ! Namelist nam_asminc in reference namelist : Assimilation increment
185	READ ( numnam_ref, nam_asminc, IOSTAT = ios, ERR = 901)
186	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in reference namelist', lwp )
187
188	REWIND( numnam_cfg ) ! Namelist nam_asminc in configuration namelist : Assimilation increment
189	READ ( numnam_cfg, nam_asminc, IOSTAT = ios, ERR = 902 )
190	902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in configuration namelist', lwp )
191	IF(lwm) WRITE ( numond, nam_asminc )
192
193	! Control print
194	IF(lwp) THEN
195	WRITE(numout,*)
196	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
197	WRITE(numout,*) '~~~~~~~~~~~~'
198	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
199	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
200	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
201	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
202	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
203	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
204	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
205	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
206	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
207	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
208	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
209	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
210	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
211	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
212	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
213	WRITE(numout,*) ' Choice of MLD for physics assimilation mld_choice = ', mld_choice
214	ENDIF
215
216	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
217	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
218	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
219	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
220
221	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
222	icycper = nitend - nit000 + 1 ! Cycle interval length
223
224	CALL calc_date( nit000, nitend , ndate0, iitend_date ) ! Date of final time step
225	CALL calc_date( nit000, nitbkg_r , ndate0, iitbkg_date ) ! Background time for Jb referenced to ndate0
226	CALL calc_date( nit000, nitdin_r , ndate0, iitdin_date ) ! Background time for DI referenced to ndate0
227	CALL calc_date( nit000, nitiaustr_r, ndate0, iitiaustr_date ) ! IAU start time referenced to ndate0
228	CALL calc_date( nit000, nitiaufin_r, ndate0, iitiaufin_date ) ! IAU end time referenced to ndate0
229	!
230	IF(lwp) THEN
231	WRITE(numout,*)
232	WRITE(numout,*) ' Time steps referenced to current cycle:'
233	WRITE(numout,*) ' iitrst = ', nit000 - 1
234	WRITE(numout,*) ' nit000 = ', nit000
235	WRITE(numout,*) ' nitend = ', nitend
236	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
237	WRITE(numout,*) ' nitdin_r = ', nitdin_r
238	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
239	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
240	WRITE(numout,*)
241	WRITE(numout,*) ' Dates referenced to current cycle:'
242	WRITE(numout,*) ' ndastp = ', ndastp
243	WRITE(numout,*) ' ndate0 = ', ndate0
244	WRITE(numout,*) ' iitend_date = ', iitend_date
245	WRITE(numout,*) ' iitbkg_date = ', iitbkg_date
246	WRITE(numout,*) ' iitdin_date = ', iitdin_date
247	WRITE(numout,*) ' iitiaustr_date = ', iitiaustr_date
248	WRITE(numout,*) ' iitiaufin_date = ', iitiaufin_date
249	ENDIF
250
251	IF ( nacc /= 0 ) &
252	& CALL ctl_stop( ' nacc /= 0 and key_asminc :', &
253	& ' Assimilation increments have only been implemented', &
254	& ' for synchronous time stepping' )
255
256	IF ( ( ln_asmdin ).AND.( ln_asmiau ) ) &
257	& CALL ctl_stop( ' ln_asmdin and ln_asmiau :', &
258	& ' Choose Direct Initialization OR Incremental Analysis Updating')
259
260	IF ( ( ( .NOT. ln_asmdin ).AND.( .NOT. ln_asmiau ) ) &
261	.AND.( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ) .OR. ( ln_seaiceinc) )) &
262	& CALL ctl_stop( ' One or more of ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc is set to .true.', &
263	& ' but ln_asmdin and ln_asmiau are both set to .false. :', &
264	& ' Inconsistent options')
265
266	IF ( ( niaufn /= 0 ).AND.( niaufn /= 1 ) ) &
267	& CALL ctl_stop( ' niaufn /= 0 or niaufn /=1 :', &
268	& ' Type IAU weighting function is invalid')
269
270	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ).AND.( .NOT. ln_seaiceinc ) &
271	& ) &
272	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc are set to .false. :', &
273	& ' The assimilation increments are not applied')
274
275	IF ( ( ln_asmiau ).AND.( nitiaustr == nitiaufin ) ) &
276	& CALL ctl_stop( ' nitiaustr = nitiaufin :', &
277	& ' IAU interval is of zero length')
278
279	IF ( ( ln_asmiau ).AND.( ( nitiaustr_r < nit000 ).OR.( nitiaufin_r > nitend ) ) ) &
280	& CALL ctl_stop( ' nitiaustr or nitiaufin :', &
281	& ' IAU starting or final time step is outside the cycle interval', &
282	& ' Valid range nit000 to nitend')
283
284	IF ( ( nitbkg_r < nit000 - 1 ).OR.( nitbkg_r > nitend ) ) &
285	& CALL ctl_stop( ' nitbkg :', &
286	& ' Background time step is outside the cycle interval')
287
288	IF ( ( nitdin_r < nit000 - 1 ).OR.( nitdin_r > nitend ) ) &
289	& CALL ctl_stop( ' nitdin :', &
290	& ' Background time step for Direct Initialization is outside', &
291	& ' the cycle interval')
292
293	IF ( nstop > 0 ) RETURN ! if there are any errors then go no further
294
295	!--------------------------------------------------------------------
296	! Initialize the Incremental Analysis Updating weighting function
297	!--------------------------------------------------------------------
298
299	IF ( ln_asmiau ) THEN
300
301	ALLOCATE( wgtiau( icycper ) )
302
303	wgtiau(:) = 0.0
304
305	IF ( niaufn == 0 ) THEN
306
307	!---------------------------------------------------------
308	! Constant IAU forcing
309	!---------------------------------------------------------
310
311	DO jt = 1, iiauper
312	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
313	END DO
314
315	ELSEIF ( niaufn == 1 ) THEN
316
317	!---------------------------------------------------------
318	! Linear hat-like, centred in middle of IAU interval
319	!---------------------------------------------------------
320
321	! Compute the normalization factor
322	znorm = 0.0
323	IF ( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
324	imid = iiauper / 2
325	DO jt = 1, imid
326	znorm = znorm + REAL( jt )
327	END DO
328	znorm = 2.0 * znorm
329	ELSE ! Odd number of time steps in IAU interval
330	imid = ( iiauper + 1 ) / 2
331	DO jt = 1, imid - 1
332	znorm = znorm + REAL( jt )
333	END DO
334	znorm = 2.0 * znorm + REAL( imid )
335	ENDIF
336	znorm = 1.0 / znorm
337
338	DO jt = 1, imid - 1
339	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
340	END DO
341	DO jt = imid, iiauper
342	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
343	END DO
344
345	ENDIF
346
347	! Test that the integral of the weights over the weighting interval equals 1
348	IF(lwp) THEN
349	WRITE(numout,*)
350	WRITE(numout,*) 'asm_inc_init : IAU weights'
351	WRITE(numout,*) '~~~~~~~~~~~~'
352	WRITE(numout,*) ' time step IAU weight'
353	WRITE(numout,*) ' ========= ====================='
354	ztotwgt = 0.0
355	DO jt = 1, icycper
356	ztotwgt = ztotwgt + wgtiau(jt)
357	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
358	END DO
359	WRITE(numout,*) ' ==================================='
360	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
361	WRITE(numout,*) ' ==================================='
362	ENDIF
363
364	ENDIF
365
366	!--------------------------------------------------------------------
367	! Allocate and initialize the increment arrays
368	!--------------------------------------------------------------------
369
370	IF ( ln_trainc ) THEN
371	ALLOCATE( t_bkginc(jpi,jpj,jpk) )
372	ALLOCATE( s_bkginc(jpi,jpj,jpk) )
373	t_bkginc(:,:,:) = 0.0
374	s_bkginc(:,:,:) = 0.0
375	ENDIF
376	IF ( ln_dyninc ) THEN
377	ALLOCATE( u_bkginc(jpi,jpj,jpk) )
378	ALLOCATE( v_bkginc(jpi,jpj,jpk) )
379	u_bkginc(:,:,:) = 0.0
380	v_bkginc(:,:,:) = 0.0
381	ENDIF
382	IF ( ln_sshinc ) THEN
383	ALLOCATE( ssh_bkginc(jpi,jpj) )
384	ssh_bkginc(:,:) = 0.0
385	ENDIF
386	IF ( ln_seaiceinc ) THEN
387	ALLOCATE( seaice_bkginc(jpi,jpj))
388	seaice_bkginc(:,:) = 0.0
389	ENDIF
390	#if defined key_asminc
391	ALLOCATE( ssh_iau(jpi,jpj) )
392	ssh_iau(:,:) = 0.0
393	#endif
394	IF ( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ).OR.( ln_seaiceinc ) ) THEN
395
396	!--------------------------------------------------------------------
397	! Read the increments from file
398	!--------------------------------------------------------------------
399
400	CALL iom_open( c_asminc, inum )
401
402	CALL iom_get( inum, 'time', zdate_inc )
403
404	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
405	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
406	z_inc_dateb = zdate_inc
407	z_inc_datef = zdate_inc
408
409	IF(lwp) THEN
410	WRITE(numout,*)
411	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid ', &
412	& ' between dates ', NINT( z_inc_dateb ),' and ', &
413	& NINT( z_inc_datef )
414	WRITE(numout,*) '~~~~~~~~~~~~'
415	ENDIF
416
417	IF ( ( NINT( z_inc_dateb ) < ndastp ) &
418	& .OR.( NINT( z_inc_datef ) > iitend_date ) ) &
419	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
420	& ' outside the assimilation interval' )
421
422	IF ( ( ln_asmdin ).AND.( NINT( zdate_inc ) /= iitdin_date ) ) &
423	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
424	& ' not agree with Direct Initialization time' )
425
426	IF ( ln_trainc ) THEN
427
428	IF (ln_sco) THEN
429
430	ALLOCATE(z_mld(jpi,jpj))
431	SELECT CASE(mld_choice)
432	CASE(1)
433	z_mld = hmld
434	CASE(2)
435	z_mld = hmlp
436	CASE(3)
437	#if defined key_karaml
438	IF ( ln_kara ) THEN
439	z_mld = hmld_kara
440	ELSE
441	CALL ctl_stop("Kara mixed layer not calculated as ln_kara=.false.")
442	ENDIF
443	#else
444	CALL ctl_stop("Kara mixed layer not defined in current version of NEMO") ! JW: Safety feature, should be removed
445	! once the Kara mixed layer is available
446	#endif
447	CASE(4)
448	z_mld = hmld_tref
449	END SELECT
450
451	ALLOCATE( t_bkginc_2d(jpi,jpj) )
452	CALL iom_get( inum, jpdom_autoglo, 'bckinsurft', t_bkginc_2d, 1)
453	#if defined key_bdy
454	DO jk = 1,jpkm1
455	WHERE( z_mld(:,:) > fsdepw(:,:,jk) )
456	t_bkginc(:,:,jk) = t_bkginc_2d(:,:) * 0.5 * &
457	& ( 1 + cos( (fsdept(:,:,jk)/z_mld(:,:) ) * rpi ) )
458
459	t_bkginc(:,:,jk) = t_bkginc(:,:,jk) * bdytmask(:,:)
460	ELSEWHERE
461	t_bkginc(:,:,jk) = 0.
462	ENDWHERE
463	ENDDO
464	#else
465	t_bkginc(:,:,:) = 0.
466	#endif
467	s_bkginc(:,:,:) = 0.
468
469	DEALLOCATE(z_mld, t_bkginc_2d)
470
471	ELSE
472
473	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
474	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
475	! Apply the masks
476	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
477	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
478	! Set missing increments to 0.0 rather than 1e+20
479	! to allow for differences in masks
480	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
481	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
482
483	ENDIF
484
485	ENDIF
486
487	IF ( ln_dyninc ) THEN
488	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
489	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
490	! Apply the masks
491	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
492	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
493	! Set missing increments to 0.0 rather than 1e+20
494	! to allow for differences in masks
495	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
496	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
497	ENDIF
498
499	IF ( ln_sshinc ) THEN
500	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
501	! Apply the masks
502	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
503	! Set missing increments to 0.0 rather than 1e+20
504	! to allow for differences in masks
505	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
506	ENDIF
507
508	IF ( ln_seaiceinc ) THEN
509	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
510	! Apply the masks
511	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
512	! Set missing increments to 0.0 rather than 1e+20
513	! to allow for differences in masks
514	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
515	ENDIF
516
517	CALL iom_close( inum )
518
519	ENDIF
520
521	!-----------------------------------------------------------------------
522	! Apply divergence damping filter
523	!-----------------------------------------------------------------------
524
525	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN
526
527	CALL wrk_alloc(jpi,jpj,hdiv)
528
529	DO jt = 1, nn_divdmp
530
531	DO jk = 1, jpkm1
532
533	hdiv(:,:) = 0._wp
534
535	DO jj = 2, jpjm1
536	DO ji = fs_2, fs_jpim1 ! vector opt.
537	hdiv(ji,jj) = &
538	( e2u(ji ,jj ) * fse3u(ji ,jj ,jk) * u_bkginc(ji ,jj ,jk) &
539	- e2u(ji-1,jj ) * fse3u(ji-1,jj ,jk) * u_bkginc(ji-1,jj ,jk) &
540	+ e1v(ji ,jj ) * fse3v(ji ,jj ,jk) * v_bkginc(ji ,jj ,jk) &
541	- e1v(ji ,jj-1) * fse3v(ji ,jj-1,jk) * v_bkginc(ji ,jj-1,jk) ) &
542	/ ( e1t(ji,jj) * e2t(ji,jj) * fse3t(ji,jj,jk) )
543	END DO
544	END DO
545
546	CALL lbc_lnk( hdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
547
548	DO jj = 2, jpjm1
549	DO ji = fs_2, fs_jpim1 ! vector opt.
550	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) &
551	- e1t(ji ,jj)e2t(ji ,jj) hdiv(ji ,jj) ) &
552	/ e1u(ji,jj) * umask(ji,jj,jk)
553	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) &
554	- e1t(ji,jj )e2t(ji,jj ) hdiv(ji,jj ) ) &
555	/ e2v(ji,jj) * vmask(ji,jj,jk)
556	END DO
557	END DO
558
559	END DO
560
561	END DO
562
563	CALL wrk_dealloc(jpi,jpj,hdiv)
564
565	ENDIF
566
567
568
569	!-----------------------------------------------------------------------
570	! Allocate and initialize the background state arrays
571	!-----------------------------------------------------------------------
572
573	IF ( ln_asmdin ) THEN
574
575	ALLOCATE( t_bkg(jpi,jpj,jpk) )
576	ALLOCATE( s_bkg(jpi,jpj,jpk) )
577	ALLOCATE( u_bkg(jpi,jpj,jpk) )
578	ALLOCATE( v_bkg(jpi,jpj,jpk) )
579	ALLOCATE( ssh_bkg(jpi,jpj) )
580
581	t_bkg(:,:,:) = 0.0
582	s_bkg(:,:,:) = 0.0
583	u_bkg(:,:,:) = 0.0
584	v_bkg(:,:,:) = 0.0
585	ssh_bkg(:,:) = 0.0
586
587	!--------------------------------------------------------------------
588	! Read from file the background state at analysis time
589	!--------------------------------------------------------------------
590
591	CALL iom_open( c_asmdin, inum )
592
593	CALL iom_get( inum, 'rdastp', zdate_bkg )
594
595	IF(lwp) THEN
596	WRITE(numout,*)
597	WRITE(numout,*) 'asm_inc_init : Assimilation background state valid at : ', &
598	& NINT( zdate_bkg )
599	WRITE(numout,*) '~~~~~~~~~~~~'
600	ENDIF
601
602	IF ( NINT( zdate_bkg ) /= iitdin_date ) &
603	& CALL ctl_warn( ' Validity time of assimilation background state does', &
604	& ' not agree with Direct Initialization time' )
605
606	IF ( ln_trainc ) THEN
607	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
608	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
609	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
610	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
611	ENDIF
612
613	IF ( ln_dyninc ) THEN
614	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
615	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
616	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
617	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
618	ENDIF
619
620	IF ( ln_sshinc ) THEN
621	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
622	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
623	ENDIF
624
625	CALL iom_close( inum )
626
627	ENDIF
628	!
629	END SUBROUTINE asm_inc_init
630
631
632	SUBROUTINE calc_date( kit000, kt, kdate0, kdate )
633	!!----------------------------------------------------------------------
634	!! * ROUTINE calc_date *
635	!!
636	!! ** Purpose : Compute the calendar date YYYYMMDD at a given time step.
637	!!
638	!! ** Method : Compute the calendar date YYYYMMDD at a given time step.
639	!!
640	!! ** Action :
641	!!----------------------------------------------------------------------
642	INTEGER, INTENT(IN) :: kit000 ! Initial time step
643	INTEGER, INTENT(IN) :: kt ! Current time step referenced to kit000
644	INTEGER, INTENT(IN) :: kdate0 ! Initial date
645	INTEGER, INTENT(OUT) :: kdate ! Current date reference to kdate0
646	!
647	INTEGER :: iyea0 ! Initial year
648	INTEGER :: imon0 ! Initial month
649	INTEGER :: iday0 ! Initial day
650	INTEGER :: iyea ! Current year
651	INTEGER :: imon ! Current month
652	INTEGER :: iday ! Current day
653	INTEGER :: idaystp ! Number of days between initial and current date
654	INTEGER :: idaycnt ! Day counter
655
656	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
657
658	!-----------------------------------------------------------------------
659	! Compute the calendar date YYYYMMDD
660	!-----------------------------------------------------------------------
661
662	! Initial date
663	iyea0 = kdate0 / 10000
664	imon0 = ( kdate0 - ( iyea0 * 10000 ) ) / 100
665	iday0 = kdate0 - ( iyea0 * 10000 ) - ( imon0 * 100 )
666
667	! Check that kt >= kit000 - 1
668	IF ( kt < kit000 - 1 ) CALL ctl_stop( ' kt must be >= kit000 - 1')
669
670	! If kt = kit000 - 1 then set the date to the restart date
671	IF ( kt == kit000 - 1 ) THEN
672
673	kdate = ndastp
674	RETURN
675
676	ENDIF
677
678	! Compute the number of days from the initial date
679	idaystp = INT( REAL( kt - kit000 ) * rdt / 86400. )
680
681	iday = iday0
682	imon = imon0
683	iyea = iyea0
684	idaycnt = 0
685
686	CALL calc_month_len( iyea, imonth_len )
687
688	DO WHILE ( idaycnt < idaystp )
689	iday = iday + 1
690	IF ( iday > imonth_len(imon) ) THEN
691	iday = 1
692	imon = imon + 1
693	ENDIF
694	IF ( imon > 12 ) THEN
695	imon = 1
696	iyea = iyea + 1
697	CALL calc_month_len( iyea, imonth_len ) ! update month lengths
698	ENDIF
699	idaycnt = idaycnt + 1
700	END DO
701	!
702	kdate = iyea * 10000 + imon * 100 + iday
703	!
704	END SUBROUTINE
705
706
707	SUBROUTINE calc_month_len( iyear, imonth_len )
708	!!----------------------------------------------------------------------
709	!! * ROUTINE calc_month_len *
710	!!
711	!! ** Purpose : Compute the number of days in a months given a year.
712	!!
713	!! ** Method :
714	!!----------------------------------------------------------------------
715	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
716	INTEGER :: iyear !: year
717	!!----------------------------------------------------------------------
718	!
719	! length of the month of the current year (from nleapy, read in namelist)
720	IF ( nleapy < 2 ) THEN
721	imonth_len(:) = (/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
722	IF ( nleapy == 1 ) THEN ! we are using calendar with leap years
723	IF ( MOD(iyear, 4) == 0 .AND. ( MOD(iyear, 400) == 0 .OR. MOD(iyear, 100) /= 0 ) ) THEN
724	imonth_len(2) = 29
725	ENDIF
726	ENDIF
727	ELSE
728	imonth_len(:) = nleapy ! all months with nleapy days per year
729	ENDIF
730	!
731	END SUBROUTINE
732
733
734	SUBROUTINE tra_asm_inc( kt )
735	!!----------------------------------------------------------------------
736	!! * ROUTINE tra_asm_inc *
737	!!
738	!! ** Purpose : Apply the tracer (T and S) assimilation increments
739	!!
740	!! ** Method : Direct initialization or Incremental Analysis Updating
741	!!
742	!! ** Action :
743	!!----------------------------------------------------------------------
744	INTEGER, INTENT(IN) :: kt ! Current time step
745	!
746	INTEGER :: ji,jj,jk
747	INTEGER :: it
748	REAL(wp) :: zincwgt ! IAU weight for current time step
749	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
750	!!----------------------------------------------------------------------
751
752	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
753	! used to prevent the applied increments taking the temperature below the local freezing point
754
755	DO jk = 1, jpkm1
756	fzptnz(:,:,jk) = eos_fzp( tsn(:,:,jk,jp_sal), fsdept(:,:,jk) )
757	END DO
758
759	IF ( ln_asmiau ) THEN
760
761	!--------------------------------------------------------------------
762	! Incremental Analysis Updating
763	!--------------------------------------------------------------------
764
765	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
766
767	it = kt - nit000 + 1
768	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
769
770	IF(lwp) THEN
771	WRITE(numout,*)
772	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
773	WRITE(numout,*) '~~~~~~~~~~~~'
774	ENDIF
775
776	! Update the tracer tendencies
777	DO jk = 1, jpkm1
778	IF (ln_temnofreeze) THEN
779	! Do not apply negative increments if the temperature will fall below freezing
780	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
781	& tsn(:,:,jk,jp_tem) + tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
782	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
783	END WHERE
784	ELSE
785	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
786	ENDIF
787	IF (ln_salfix) THEN
788	! Do not apply negative increments if the salinity will fall below a specified
789	! minimum value salfixmin
790	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
791	& tsn(:,:,jk,jp_sal) + tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
792	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
793	END WHERE
794	ELSE
795	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
796	ENDIF
797	END DO
798
799	ENDIF
800
801	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
802	DEALLOCATE( t_bkginc )
803	DEALLOCATE( s_bkginc )
804	ENDIF
805
806
807	ELSEIF ( ln_asmdin ) THEN
808
809	!--------------------------------------------------------------------
810	! Direct Initialization
811	!--------------------------------------------------------------------
812
813	IF ( kt == nitdin_r ) THEN
814
815	neuler = 0 ! Force Euler forward step
816
817	! Initialize the now fields with the background + increment
818	IF (ln_temnofreeze) THEN
819	! Do not apply negative increments if the temperature will fall below freezing
820	WHERE( t_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
821	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
822	END WHERE
823	ELSE
824	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
825	ENDIF
826	IF (ln_salfix) THEN
827	! Do not apply negative increments if the salinity will fall below a specified
828	! minimum value salfixmin
829	WHERE( s_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
830	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
831	END WHERE
832	ELSE
833	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
834	ENDIF
835
836	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
837
838	CALL eos( tsb, rhd, rhop, gdept_0(:,:,:) ) ! Before potential and in situ densities
839	!!gm fabien
840	! CALL eos( tsb, rhd, rhop ) ! Before potential and in situ densities
841	!!gm
842
843
844	IF( ln_zps .AND. .NOT. lk_c1d .AND. .NOT. ln_isfcav) &
845	& CALL zps_hde ( kt, jpts, tsb, gtsu, gtsv, & ! Partial steps: before horizontal gradient
846	& rhd, gru , grv ) ! of t, s, rd at the last ocean level
847	IF( ln_zps .AND. .NOT. lk_c1d .AND. ln_isfcav) &
848	& CALL zps_hde_isf( nit000, jpts, tsb, gtsu, gtsv, & ! Partial steps for top cell (ISF)
849	& rhd, gru , grv , aru , arv , gzu , gzv , ge3ru , ge3rv , &
850	& gtui, gtvi, grui, grvi, arui, arvi, gzui, gzvi, ge3rui, ge3rvi ) ! of t, s, rd at the last ocean level
851
852	#if defined key_zdfkpp
853	CALL eos( tsn, rhd, fsdept_n(:,:,:) ) ! Compute rhd
854	!!gm fabien CALL eos( tsn, rhd ) ! Compute rhd
855	#endif
856
857	DEALLOCATE( t_bkginc )
858	DEALLOCATE( s_bkginc )
859	DEALLOCATE( t_bkg )
860	DEALLOCATE( s_bkg )
861	ENDIF
862	!
863	ENDIF
864	! Perhaps the following call should be in step
865	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
866	!
867	END SUBROUTINE tra_asm_inc
868
869
870	SUBROUTINE dyn_asm_inc( kt )
871	!!----------------------------------------------------------------------
872	!! * ROUTINE dyn_asm_inc *
873	!!
874	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
875	!!
876	!! ** Method : Direct initialization or Incremental Analysis Updating.
877	!!
878	!! ** Action :
879	!!----------------------------------------------------------------------
880	INTEGER, INTENT(IN) :: kt ! Current time step
881	!
882	INTEGER :: jk
883	INTEGER :: it
884	REAL(wp) :: zincwgt ! IAU weight for current time step
885	!!----------------------------------------------------------------------
886
887	IF ( ln_asmiau ) THEN
888
889	!--------------------------------------------------------------------
890	! Incremental Analysis Updating
891	!--------------------------------------------------------------------
892
893	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
894
895	it = kt - nit000 + 1
896	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
897
898	IF(lwp) THEN
899	WRITE(numout,*)
900	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', &
901	& kt,' with IAU weight = ', wgtiau(it)
902	WRITE(numout,*) '~~~~~~~~~~~~'
903	ENDIF
904
905	! Update the dynamic tendencies
906	DO jk = 1, jpkm1
907	ua(:,:,jk) = ua(:,:,jk) + u_bkginc(:,:,jk) * zincwgt
908	va(:,:,jk) = va(:,:,jk) + v_bkginc(:,:,jk) * zincwgt
909	END DO
910
911	IF ( kt == nitiaufin_r ) THEN
912	DEALLOCATE( u_bkginc )
913	DEALLOCATE( v_bkginc )
914	ENDIF
915
916	ENDIF
917
918	ELSEIF ( ln_asmdin ) THEN
919
920	!--------------------------------------------------------------------
921	! Direct Initialization
922	!--------------------------------------------------------------------
923
924	IF ( kt == nitdin_r ) THEN
925
926	neuler = 0 ! Force Euler forward step
927
928	! Initialize the now fields with the background + increment
929	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
930	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
931
932	ub(:,:,:) = un(:,:,:) ! Update before fields
933	vb(:,:,:) = vn(:,:,:)
934
935	DEALLOCATE( u_bkg )
936	DEALLOCATE( v_bkg )
937	DEALLOCATE( u_bkginc )
938	DEALLOCATE( v_bkginc )
939	ENDIF
940	!
941	ENDIF
942	!
943	END SUBROUTINE dyn_asm_inc
944
945
946	SUBROUTINE ssh_asm_inc( kt )
947	!!----------------------------------------------------------------------
948	!! * ROUTINE ssh_asm_inc *
949	!!
950	!! ** Purpose : Apply the sea surface height assimilation increment.
951	!!
952	!! ** Method : Direct initialization or Incremental Analysis Updating.
953	!!
954	!! ** Action :
955	!!----------------------------------------------------------------------
956	INTEGER, INTENT(IN) :: kt ! Current time step
957	!
958	INTEGER :: it
959	INTEGER :: jk
960	REAL(wp) :: zincwgt ! IAU weight for current time step
961	!!----------------------------------------------------------------------
962
963	IF ( ln_asmiau ) THEN
964
965	!--------------------------------------------------------------------
966	! Incremental Analysis Updating
967	!--------------------------------------------------------------------
968
969	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
970
971	it = kt - nit000 + 1
972	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
973
974	IF(lwp) THEN
975	WRITE(numout,*)
976	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
977	& kt,' with IAU weight = ', wgtiau(it)
978	WRITE(numout,*) '~~~~~~~~~~~~'
979	ENDIF
980
981	! Save the tendency associated with the IAU weighted SSH increment
982	! (applied in dynspg.*)
983	#if defined key_asminc
984	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
985	#endif
986	IF ( kt == nitiaufin_r ) THEN
987	DEALLOCATE( ssh_bkginc )
988	ENDIF
989
990	ENDIF
991
992	ELSEIF ( ln_asmdin ) THEN
993
994	!--------------------------------------------------------------------
995	! Direct Initialization
996	!--------------------------------------------------------------------
997
998	IF ( kt == nitdin_r ) THEN
999
1000	neuler = 0 ! Force Euler forward step
1001
1002	! Initialize the now fields the background + increment
1003	sshn(:,:) = ssh_bkg(:,:) + ssh_bkginc(:,:)
1004
1005	! Update before fields
1006	sshb(:,:) = sshn(:,:)
1007
1008	IF( lk_vvl ) THEN
1009	DO jk = 1, jpk
1010	fse3t_b(:,:,jk) = fse3t_n(:,:,jk)
1011	END DO
1012	ENDIF
1013
1014	DEALLOCATE( ssh_bkg )
1015	DEALLOCATE( ssh_bkginc )
1016
1017	ENDIF
1018	!
1019	ENDIF
1020	!
1021	END SUBROUTINE ssh_asm_inc
1022
1023
1024	SUBROUTINE seaice_asm_inc( kt, kindic )
1025	!!----------------------------------------------------------------------
1026	!! * ROUTINE seaice_asm_inc *
1027	!!
1028	!! ** Purpose : Apply the sea ice assimilation increment.
1029	!!
1030	!! ** Method : Direct initialization or Incremental Analysis Updating.
1031	!!
1032	!! ** Action :
1033	!!
1034	!!----------------------------------------------------------------------
1035	IMPLICIT NONE
1036	!
1037	INTEGER, INTENT(in) :: kt ! Current time step
1038	INTEGER, INTENT(in), OPTIONAL :: kindic ! flag for disabling the deallocation
1039	!
1040	INTEGER :: it
1041	REAL(wp) :: zincwgt ! IAU weight for current time step
1042	#if defined key_lim2
1043	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
1044	REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
1045	#endif
1046	!!----------------------------------------------------------------------
1047
1048	IF ( ln_asmiau ) THEN
1049
1050	!--------------------------------------------------------------------
1051	! Incremental Analysis Updating
1052	!--------------------------------------------------------------------
1053
1054	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
1055
1056	it = kt - nit000 + 1
1057	zincwgt = wgtiau(it) ! IAU weight for the current time step
1058	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
1059
1060	IF(lwp) THEN
1061	WRITE(numout,*)
1062	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', &
1063	& kt,' with IAU weight = ', wgtiau(it)
1064	WRITE(numout,*) '~~~~~~~~~~~~'
1065	ENDIF
1066
1067	! Sea-ice : LIM-3 case (to add)
1068
1069	#if defined key_lim2
1070	! Sea-ice : LIM-2 case
1071	zofrld (:,:) = frld(:,:)
1072	zohicif(:,:) = hicif(:,:)
1073	!
1074	frld = MIN( MAX( frld (:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1075	pfrld = MIN( MAX( pfrld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1076	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1077	!
1078	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1079	!
1080	! Nudge sea ice depth to bring it up to a required minimum depth
1081	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1082	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1083	ELSEWHERE
1084	zhicifinc(:,:) = 0.0_wp
1085	END WHERE
1086	!
1087	! nudge ice depth
1088	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1089	phicif(:,:) = phicif(:,:) + zhicifinc(:,:)
1090	!
1091	! seaice salinity balancing (to add)
1092	#endif
1093
1094	#if defined key_cice && defined key_asminc
1095	! Sea-ice : CICE case. Pass ice increment tendency into CICE
1096	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
1097	#endif
1098
1099	IF ( kt == nitiaufin_r ) THEN
1100	DEALLOCATE( seaice_bkginc )
1101	ENDIF
1102
1103	ELSE
1104
1105	#if defined key_cice && defined key_asminc
1106	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1107	ndaice_da(:,:) = 0.0_wp
1108	#endif
1109
1110	ENDIF
1111
1112	ELSEIF ( ln_asmdin ) THEN
1113
1114	!--------------------------------------------------------------------
1115	! Direct Initialization
1116	!--------------------------------------------------------------------
1117
1118	IF ( kt == nitdin_r ) THEN
1119
1120	neuler = 0 ! Force Euler forward step
1121
1122	! Sea-ice : LIM-3 case (to add)
1123
1124	#if defined key_lim2
1125	! Sea-ice : LIM-2 case.
1126	zofrld(:,:)=frld(:,:)
1127	zohicif(:,:)=hicif(:,:)
1128	!
1129	! Initialize the now fields the background + increment
1130	frld (:,:) = MIN( MAX( frld(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
1131	pfrld(:,:) = frld(:,:)
1132	fr_i (:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1133	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1134	!
1135	! Nudge sea ice depth to bring it up to a required minimum depth
1136	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1137	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1138	ELSEWHERE
1139	zhicifinc(:,:) = 0.0_wp
1140	END WHERE
1141	!
1142	! nudge ice depth
1143	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1144	phicif(:,:) = phicif(:,:)
1145	!
1146	! seaice salinity balancing (to add)
1147	#endif
1148
1149	#if defined key_cice && defined key_asminc
1150	! Sea-ice : CICE case. Pass ice increment tendency into CICE
1151	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
1152	#endif
1153	IF ( .NOT. PRESENT(kindic) ) THEN
1154	DEALLOCATE( seaice_bkginc )
1155	END IF
1156
1157	ELSE
1158
1159	#if defined key_cice && defined key_asminc
1160	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1161	ndaice_da(:,:) = 0.0_wp
1162	#endif
1163
1164	ENDIF
1165
1166	!#if defined defined key_lim2 \|\| defined key_cice
1167	!
1168	! IF (ln_seaicebal ) THEN
1169	! !! balancing salinity increments
1170	! !! simple case from limflx.F90 (doesn't include a mass flux)
1171	! !! assumption is that as ice concentration is reduced or increased
1172	! !! the snow and ice depths remain constant
1173	! !! note that snow is being created where ice concentration is being increased
1174	! !! - could be more sophisticated and
1175	! !! not do this (but would need to alter h_snow)
1176	!
1177	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
1178	!
1179	! DO jj = 1, jpj
1180	! DO ji = 1, jpi
1181	! ! calculate change in ice and snow mass per unit area
1182	! ! positive values imply adding salt to the ocean (results from ice formation)
1183	! ! fwf : ice formation and melting
1184	!
1185	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
1186	!
1187	! ! change salinity down to mixed layer depth
1188	! mld=hmld_kara(ji,jj)
1189	!
1190	! ! prevent small mld
1191	! ! less than 10m can cause salinity instability
1192	! IF (mld < 10) mld=10
1193	!
1194	! ! set to bottom of a level
1195	! DO jk = jpk-1, 2, -1
1196	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
1197	! mld=gdepw(ji,jj,jk+1)
1198	! jkmax=jk
1199	! ENDIF
1200	! ENDDO
1201	!
1202	! ! avoid applying salinity balancing in shallow water or on land
1203	! !
1204	!
1205	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
1206	!
1207	! dsal_ocn=0.0_wp
1208	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
1209	!
1210	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
1211	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
1212	!
1213	! ! put increments in for levels in the mixed layer
1214	! ! but prevent salinity below a threshold value
1215	!
1216	! DO jk = 1, jkmax
1217	!
1218	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
1219	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
1220	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
1221	! ENDIF
1222	!
1223	! ENDDO
1224	!
1225	! ! ! salt exchanges at the ice/ocean interface
1226	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
1227	! !
1228	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
1229	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
1230	! !!
1231	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
1232	! !! ! E-P (kg m-2 s-2)
1233	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
1234	! ENDDO !ji
1235	! ENDDO !jj!
1236	!
1237	! ENDIF !ln_seaicebal
1238	!
1239	!#endif
1240
1241	ENDIF
1242
1243	END SUBROUTINE seaice_asm_inc
1244
1245	!!======================================================================
1246	END MODULE asminc

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