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asminc.F90 in branches/UKMO/dev_r5518_obs_oper_update_icethick/NEMOGCM/NEMO/OPA_SRC/ASM – NEMO

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source: branches/UKMO/dev_r5518_obs_oper_update_icethick/NEMOGCM/NEMO/OPA_SRC/ASM/asminc.F90 @ 10181

Last change on this file since 10181 was 10181, checked in by emmafiedler, 6 years ago
Working version of ice thickness assimilation updates
File size: 58.9 KB

Line
1	MODULE asminc
2	!!======================================================================
3	!! * MODULE asminc *
4	!! Assimilation increment : Apply an increment generated by data
5	!! assimilation
6	!!======================================================================
7	!! History : ! 2007-03 (M. Martin) Met Office version
8	!! ! 2007-04 (A. Weaver) calc_date original code
9	!! ! 2007-04 (A. Weaver) Merge with OPAVAR/NEMOVAR
10	!! NEMO 3.3 ! 2010-05 (D. Lea) Update to work with NEMO v3.2
11	!! - ! 2010-05 (D. Lea) add calc_month_len routine based on day_init
12	!! 3.4 ! 2012-10 (A. Weaver and K. Mogensen) Fix for direct initialization
13	!!----------------------------------------------------------------------
14
15	!!----------------------------------------------------------------------
16	!! 'key_asminc' : Switch on the assimilation increment interface
17	!!----------------------------------------------------------------------
18	!! asm_inc_init : Initialize the increment arrays and IAU weights
19	!! calc_date : Compute the calendar date YYYYMMDD on a given step
20	!! tra_asm_inc : Apply the tracer (T and S) increments
21	!! dyn_asm_inc : Apply the dynamic (u and v) increments
22	!! ssh_asm_inc : Apply the SSH increment
23	!! seaice_asm_inc : Apply the seaice concentration increment
24	!! sit_asm_inc : Apply the sea ice thickness increment
25	!!----------------------------------------------------------------------
26	USE wrk_nemo ! Memory Allocation
27	USE par_oce ! Ocean space and time domain variables
28	USE dom_oce ! Ocean space and time domain
29	USE domvvl ! domain: variable volume level
30	USE oce ! Dynamics and active tracers defined in memory
31	USE ldfdyn_oce ! ocean dynamics: lateral physics
32	USE eosbn2 ! Equation of state - in situ and potential density
33	USE zpshde ! Partial step : Horizontal Derivative
34	USE iom ! Library to read input files
35	USE asmpar ! Parameters for the assmilation interface
36	USE c1d ! 1D initialization
37	USE in_out_manager ! I/O manager
38	USE lib_mpp ! MPP library
39	#if defined key_lim2
40	USE ice_2 ! LIM2
41	#endif
42	#if defined key_cice && defined key_asminc
43	USE sbc_ice, ONLY : & ! CICE Ice model variables
44	& ndaice_da, ndsit_da, nfresh_da, nfsalt_da
45	#endif
46	USE sbc_oce ! Surface boundary condition variables.
47
48	IMPLICIT NONE
49	PRIVATE
50
51	PUBLIC asm_inc_init !: Initialize the increment arrays and IAU weights
52	PUBLIC calc_date !: Compute the calendar date YYYYMMDD on a given step
53	PUBLIC tra_asm_inc !: Apply the tracer (T and S) increments
54	PUBLIC dyn_asm_inc !: Apply the dynamic (u and v) increments
55	PUBLIC ssh_asm_inc !: Apply the SSH increment
56	PUBLIC seaice_asm_inc !: Apply the seaice concentration increment
57	PUBLIC sit_asm_inc !: Apply the seaice thickness increment
58
59	#if defined key_asminc
60	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
61	#else
62	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
63	#endif
64	LOGICAL, PUBLIC :: ln_bkgwri = .FALSE. !: No output of the background state fields
65	LOGICAL, PUBLIC :: ln_asmiau = .FALSE. !: No applying forcing with an assimilation increment
66	LOGICAL, PUBLIC :: ln_asmdin = .FALSE. !: No direct initialization
67	LOGICAL, PUBLIC :: ln_trainc = .FALSE. !: No tracer (T and S) assimilation increments
68	LOGICAL, PUBLIC :: ln_dyninc = .FALSE. !: No dynamics (u and v) assimilation increments
69	LOGICAL, PUBLIC :: ln_sshinc = .FALSE. !: No sea surface height assimilation increment
70	LOGICAL, PUBLIC :: ln_seaiceinc = .FALSE. !: No sea ice concentration increment
71	LOGICAL, PUBLIC :: ln_sitinc = .FALSE. !: No sea ice thickness increment
72	LOGICAL, PUBLIC :: ln_salfix = .FALSE. !: Apply minimum salinity check
73	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
74	INTEGER, PUBLIC :: nn_divdmp !: Apply divergence damping filter nn_divdmp times
75
76	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkg , s_bkg !: Background temperature and salinity
77	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkg , v_bkg !: Background u- & v- velocity components
78	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkginc, s_bkginc !: Increment to the background T & S
79	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkginc, v_bkginc !: Increment to the u- & v-components
80	REAL(wp), PUBLIC, DIMENSION(:) , ALLOCATABLE :: wgtiau !: IAU weights for each time step
81	REAL(wp), PUBLIC, DIMENSION(:,:), ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
82	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
83	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
84	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
85	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
86	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
87	!
88	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
89	! !: = 1 Linear hat-like, centred in middle of IAU interval
90	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
91
92	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
93	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
94	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: sit_bkginc ! Increment to the background sea ice thickness
95
96	!! * Substitutions
97	# include "domzgr_substitute.h90"
98	# include "ldfdyn_substitute.h90"
99	# include "vectopt_loop_substitute.h90"
100	!!----------------------------------------------------------------------
101	!! NEMO/OPA 3.3 , NEMO Consortium (2010)
102	!! $Id$
103	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
104	!!----------------------------------------------------------------------
105	CONTAINS
106
107	SUBROUTINE asm_inc_init
108	!!----------------------------------------------------------------------
109	!! * ROUTINE asm_inc_init *
110	!!
111	!! ** Purpose : Initialize the assimilation increment and IAU weights.
112	!!
113	!! ** Method : Initialize the assimilation increment and IAU weights.
114	!!
115	!! ** Action :
116	!!----------------------------------------------------------------------
117	INTEGER :: ji, jj, jk, jt ! dummy loop indices
118	INTEGER :: imid, inum ! local integers
119	INTEGER :: ios ! Local integer output status for namelist read
120	INTEGER :: iiauper ! Number of time steps in the IAU period
121	INTEGER :: icycper ! Number of time steps in the cycle
122	INTEGER :: iitend_date ! Date YYYYMMDD of final time step
123	INTEGER :: iitbkg_date ! Date YYYYMMDD of background time step for Jb term
124	INTEGER :: iitdin_date ! Date YYYYMMDD of background time step for DI
125	INTEGER :: iitiaustr_date ! Date YYYYMMDD of IAU interval start time step
126	INTEGER :: iitiaufin_date ! Date YYYYMMDD of IAU interval final time step
127	!
128	REAL(wp) :: znorm ! Normalization factor for IAU weights
129	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights (should be equal to one)
130	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
131	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
132	REAL(wp) :: zdate_bkg ! Date in background state file for DI
133	REAL(wp) :: zdate_inc ! Time axis in increments file
134	!
135	REAL(wp), POINTER, DIMENSION(:,:) :: hdiv ! 2D workspace
136	!!
137	NAMELIST/nam_asminc/ ln_bkgwri, &
138	& ln_trainc, ln_dyninc, ln_sshinc, &
139	& ln_asmdin, ln_asmiau, &
140	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
141	& ln_salfix, salfixmin, nn_divdmp, &
142	& ln_seaiceinc, ln_sitinc, ln_temnofreeze
143	!!----------------------------------------------------------------------
144
145	!-----------------------------------------------------------------------
146	! Read Namelist nam_asminc : assimilation increment interface
147	!-----------------------------------------------------------------------
148	ln_sitinc = .FALSE.
149	ln_seaiceinc = .FALSE.
150	ln_temnofreeze = .FALSE.
151
152	REWIND( numnam_ref ) ! Namelist nam_asminc in reference namelist : Assimilation increment
153	READ ( numnam_ref, nam_asminc, IOSTAT = ios, ERR = 901)
154	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in reference namelist', lwp )
155
156	REWIND( numnam_cfg ) ! Namelist nam_asminc in configuration namelist : Assimilation increment
157	READ ( numnam_cfg, nam_asminc, IOSTAT = ios, ERR = 902 )
158	902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nam_asminc in configuration namelist', lwp )
159	IF(lwm) WRITE ( numond, nam_asminc )
160
161	! Control print
162	IF(lwp) THEN
163	WRITE(numout,*)
164	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
165	WRITE(numout,*) '~~~~~~~~~~~~'
166	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
167	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
168	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
169	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
170	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
171	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
172	WRITE(numout,*) ' Logical switch for applying SIC increments ln_seaiceinc = ', ln_seaiceinc
173	WRITE(numout,*) ' Logical switch for applying SIT increments ln_sitinc = ', ln_sitinc
174	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
175	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
176	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
177	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
178	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
179	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
180	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
181	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
182	ENDIF
183
184	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
185	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
186	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
187	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
188
189	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
190	icycper = nitend - nit000 + 1 ! Cycle interval length
191
192	CALL calc_date( nit000, nitend , ndate0, iitend_date ) ! Date of final time step
193	CALL calc_date( nit000, nitbkg_r , ndate0, iitbkg_date ) ! Background time for Jb referenced to ndate0
194	CALL calc_date( nit000, nitdin_r , ndate0, iitdin_date ) ! Background time for DI referenced to ndate0
195	CALL calc_date( nit000, nitiaustr_r, ndate0, iitiaustr_date ) ! IAU start time referenced to ndate0
196	CALL calc_date( nit000, nitiaufin_r, ndate0, iitiaufin_date ) ! IAU end time referenced to ndate0
197	!
198	IF(lwp) THEN
199	WRITE(numout,*)
200	WRITE(numout,*) ' Time steps referenced to current cycle:'
201	WRITE(numout,*) ' iitrst = ', nit000 - 1
202	WRITE(numout,*) ' nit000 = ', nit000
203	WRITE(numout,*) ' nitend = ', nitend
204	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
205	WRITE(numout,*) ' nitdin_r = ', nitdin_r
206	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
207	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
208	WRITE(numout,*)
209	WRITE(numout,*) ' Dates referenced to current cycle:'
210	WRITE(numout,*) ' ndastp = ', ndastp
211	WRITE(numout,*) ' ndate0 = ', ndate0
212	WRITE(numout,*) ' iitend_date = ', iitend_date
213	WRITE(numout,*) ' iitbkg_date = ', iitbkg_date
214	WRITE(numout,*) ' iitdin_date = ', iitdin_date
215	WRITE(numout,*) ' iitiaustr_date = ', iitiaustr_date
216	WRITE(numout,*) ' iitiaufin_date = ', iitiaufin_date
217	ENDIF
218
219	IF ( nacc /= 0 ) &
220	& CALL ctl_stop( ' nacc /= 0 and key_asminc :', &
221	& ' Assimilation increments have only been implemented', &
222	& ' for synchronous time stepping' )
223
224	IF ( ( ln_asmdin ).AND.( ln_asmiau ) ) &
225	& CALL ctl_stop( ' ln_asmdin and ln_asmiau :', &
226	& ' Choose Direct Initialization OR Incremental Analysis Updating')
227
228	IF ( ( ( .NOT. ln_asmdin ).AND.( .NOT. ln_asmiau ) ) &
229	& .AND.( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ) &
230	& .OR.( ln_sitinc ).OR.( ln_seaiceinc ) )) &
231	& CALL ctl_stop( ' One or more of ln_trainc, ln_dyninc, ln_sshinc,', &
232	& ' ln_sitinc and ln_seaiceinc is set to .true.', &
233	& ' but ln_asmdin and ln_asmiau are both set to .false. :', &
234	& ' Inconsistent options')
235
236	IF ( ( niaufn /= 0 ).AND.( niaufn /= 1 ) ) &
237	& CALL ctl_stop( ' niaufn /= 0 or niaufn /=1 :', &
238	& ' Type IAU weighting function is invalid')
239
240	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ) &
241	& .AND.( .NOT. ln_sitinc ).AND.( .NOT. ln_seaiceinc ) &
242	& ) &
243	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc, ln_sitinc', &
244	& ' and ln_seaiceinc are set to .false. :', &
245	& ' The assimilation increments are not applied')
246
247	IF ( ( ln_asmiau ).AND.( nitiaustr == nitiaufin ) ) &
248	& CALL ctl_stop( ' nitiaustr = nitiaufin :', &
249	& ' IAU interval is of zero length')
250
251	IF ( ( ln_asmiau ).AND.( ( nitiaustr_r < nit000 ).OR.( nitiaufin_r > nitend ) ) ) &
252	& CALL ctl_stop( ' nitiaustr or nitiaufin :', &
253	& ' IAU starting or final time step is outside the cycle interval', &
254	& ' Valid range nit000 to nitend')
255
256	IF ( ( nitbkg_r < nit000 - 1 ).OR.( nitbkg_r > nitend ) ) &
257	& CALL ctl_stop( ' nitbkg :', &
258	& ' Background time step is outside the cycle interval')
259
260	IF ( ( nitdin_r < nit000 - 1 ).OR.( nitdin_r > nitend ) ) &
261	& CALL ctl_stop( ' nitdin :', &
262	& ' Background time step for Direct Initialization is outside', &
263	& ' the cycle interval')
264
265	IF ( nstop > 0 ) RETURN ! if there are any errors then go no further
266
267	!--------------------------------------------------------------------
268	! Initialize the Incremental Analysis Updating weighting function
269	!--------------------------------------------------------------------
270
271	IF ( ln_asmiau ) THEN
272
273	ALLOCATE( wgtiau( icycper ) )
274
275	wgtiau(:) = 0.0
276
277	IF ( niaufn == 0 ) THEN
278
279	!---------------------------------------------------------
280	! Constant IAU forcing
281	!---------------------------------------------------------
282
283	DO jt = 1, iiauper
284	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
285	END DO
286
287	ELSEIF ( niaufn == 1 ) THEN
288
289	!---------------------------------------------------------
290	! Linear hat-like, centred in middle of IAU interval
291	!---------------------------------------------------------
292
293	! Compute the normalization factor
294	znorm = 0.0
295	IF ( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
296	imid = iiauper / 2
297	DO jt = 1, imid
298	znorm = znorm + REAL( jt )
299	END DO
300	znorm = 2.0 * znorm
301	ELSE ! Odd number of time steps in IAU interval
302	imid = ( iiauper + 1 ) / 2
303	DO jt = 1, imid - 1
304	znorm = znorm + REAL( jt )
305	END DO
306	znorm = 2.0 * znorm + REAL( imid )
307	ENDIF
308	znorm = 1.0 / znorm
309
310	DO jt = 1, imid - 1
311	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
312	END DO
313	DO jt = imid, iiauper
314	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
315	END DO
316
317	ENDIF
318
319	! Test that the integral of the weights over the weighting interval equals 1
320	IF(lwp) THEN
321	WRITE(numout,*)
322	WRITE(numout,*) 'asm_inc_init : IAU weights'
323	WRITE(numout,*) '~~~~~~~~~~~~'
324	WRITE(numout,*) ' time step IAU weight'
325	WRITE(numout,*) ' ========= ====================='
326	ztotwgt = 0.0
327	DO jt = 1, icycper
328	ztotwgt = ztotwgt + wgtiau(jt)
329	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
330	END DO
331	WRITE(numout,*) ' ==================================='
332	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
333	WRITE(numout,*) ' ==================================='
334	ENDIF
335
336	ENDIF
337
338	!--------------------------------------------------------------------
339	! Allocate and initialize the increment arrays
340	!--------------------------------------------------------------------
341
342	ALLOCATE( t_bkginc(jpi,jpj,jpk) )
343	ALLOCATE( s_bkginc(jpi,jpj,jpk) )
344	ALLOCATE( u_bkginc(jpi,jpj,jpk) )
345	ALLOCATE( v_bkginc(jpi,jpj,jpk) )
346	ALLOCATE( ssh_bkginc(jpi,jpj) )
347	ALLOCATE( seaice_bkginc(jpi,jpj))
348	ALLOCATE( sit_bkginc(jpi,jpj) )
349	#if defined key_asminc
350	ALLOCATE( ssh_iau(jpi,jpj) )
351	#endif
352	t_bkginc(:,:,:) = 0.0
353	s_bkginc(:,:,:) = 0.0
354	u_bkginc(:,:,:) = 0.0
355	v_bkginc(:,:,:) = 0.0
356	ssh_bkginc(:,:) = 0.0
357	seaice_bkginc(:,:) = 0.0
358	sit_bkginc(:,:) = 0.0
359	#if defined key_asminc
360	ssh_iau(:,:) = 0.0
361	#endif
362	IF ( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ).OR.( ln_sitinc ).OR.( ln_seaiceinc ) ) THEN
363
364	!--------------------------------------------------------------------
365	! Read the increments from file
366	!--------------------------------------------------------------------
367
368	CALL iom_open( c_asminc, inum )
369
370	CALL iom_get( inum, 'time', zdate_inc )
371
372	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
373	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
374	z_inc_dateb = zdate_inc
375	z_inc_datef = zdate_inc
376
377	IF(lwp) THEN
378	WRITE(numout,*)
379	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid ', &
380	& ' between dates ', NINT( z_inc_dateb ),' and ', &
381	& NINT( z_inc_datef )
382	WRITE(numout,*) '~~~~~~~~~~~~'
383	ENDIF
384
385	IF ( ( NINT( z_inc_dateb ) < ndastp ) &
386	& .OR.( NINT( z_inc_datef ) > iitend_date ) ) &
387	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
388	& ' outside the assimilation interval' )
389
390	IF ( ( ln_asmdin ).AND.( NINT( zdate_inc ) /= iitdin_date ) ) &
391	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
392	& ' not agree with Direct Initialization time' )
393
394	IF ( ln_trainc ) THEN
395	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
396	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
397	! Apply the masks
398	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
399	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
400	! Set missing increments to 0.0 rather than 1e+20
401	! to allow for differences in masks
402	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
403	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
404	ENDIF
405
406	IF ( ln_dyninc ) THEN
407	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
408	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
409	! Apply the masks
410	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
411	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
412	! Set missing increments to 0.0 rather than 1e+20
413	! to allow for differences in masks
414	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
415	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
416	ENDIF
417
418	IF ( ln_sshinc ) THEN
419	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
420	! Apply the masks
421	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
422	! Set missing increments to 0.0 rather than 1e+20
423	! to allow for differences in masks
424	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
425	ENDIF
426
427	IF ( ln_sitinc ) THEN
428	CALL iom_get( inum, jpdom_autoglo, 'bckinsit', sit_bkginc, 1 )
429	! Apply the masks
430	sit_bkginc(:,:) = sit_bkginc(:,:) * tmask(:,:,1)
431	! Set missing increments to 0.0 rather than 1e+20
432	! to allow for differences in masks
433	WHERE( ABS( sit_bkginc(:,:) ) > 1.0e+10 ) sit_bkginc(:,:) = 0.0
434	ENDIF
435
436	IF ( ln_seaiceinc ) THEN
437	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
438	! Apply the masks
439	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
440	! Set missing increments to 0.0 rather than 1e+20
441	! to allow for differences in masks
442	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
443	ENDIF
444
445	CALL iom_close( inum )
446
447	ENDIF
448
449	!-----------------------------------------------------------------------
450	! Apply divergence damping filter
451	!-----------------------------------------------------------------------
452
453	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN
454
455	CALL wrk_alloc(jpi,jpj,hdiv)
456
457	DO jt = 1, nn_divdmp
458
459	DO jk = 1, jpkm1
460
461	hdiv(:,:) = 0._wp
462
463	DO jj = 2, jpjm1
464	DO ji = fs_2, fs_jpim1 ! vector opt.
465	hdiv(ji,jj) = &
466	( e2u(ji ,jj ) * fse3u(ji ,jj ,jk) * u_bkginc(ji ,jj ,jk) &
467	- e2u(ji-1,jj ) * fse3u(ji-1,jj ,jk) * u_bkginc(ji-1,jj ,jk) &
468	+ e1v(ji ,jj ) * fse3v(ji ,jj ,jk) * v_bkginc(ji ,jj ,jk) &
469	- e1v(ji ,jj-1) * fse3v(ji ,jj-1,jk) * v_bkginc(ji ,jj-1,jk) ) &
470	/ ( e1t(ji,jj) * e2t(ji,jj) * fse3t(ji,jj,jk) )
471	END DO
472	END DO
473
474	CALL lbc_lnk( hdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
475
476	DO jj = 2, jpjm1
477	DO ji = fs_2, fs_jpim1 ! vector opt.
478	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) &
479	- e1t(ji ,jj)e2t(ji ,jj) hdiv(ji ,jj) ) &
480	/ e1u(ji,jj) * umask(ji,jj,jk)
481	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) &
482	- e1t(ji,jj )e2t(ji,jj ) hdiv(ji,jj ) ) &
483	/ e2v(ji,jj) * vmask(ji,jj,jk)
484	END DO
485	END DO
486
487	END DO
488
489	END DO
490
491	CALL wrk_dealloc(jpi,jpj,hdiv)
492
493	ENDIF
494
495
496
497	!-----------------------------------------------------------------------
498	! Allocate and initialize the background state arrays
499	!-----------------------------------------------------------------------
500
501	IF ( ln_asmdin ) THEN
502
503	ALLOCATE( t_bkg(jpi,jpj,jpk) )
504	ALLOCATE( s_bkg(jpi,jpj,jpk) )
505	ALLOCATE( u_bkg(jpi,jpj,jpk) )
506	ALLOCATE( v_bkg(jpi,jpj,jpk) )
507	ALLOCATE( ssh_bkg(jpi,jpj) )
508
509	t_bkg(:,:,:) = 0.0
510	s_bkg(:,:,:) = 0.0
511	u_bkg(:,:,:) = 0.0
512	v_bkg(:,:,:) = 0.0
513	ssh_bkg(:,:) = 0.0
514
515	!--------------------------------------------------------------------
516	! Read from file the background state at analysis time
517	!--------------------------------------------------------------------
518
519	CALL iom_open( c_asmdin, inum )
520
521	CALL iom_get( inum, 'rdastp', zdate_bkg )
522
523	IF(lwp) THEN
524	WRITE(numout,*)
525	WRITE(numout,*) 'asm_inc_init : Assimilation background state valid at : ', &
526	& NINT( zdate_bkg )
527	WRITE(numout,*) '~~~~~~~~~~~~'
528	ENDIF
529
530	IF ( NINT( zdate_bkg ) /= iitdin_date ) &
531	& CALL ctl_warn( ' Validity time of assimilation background state does', &
532	& ' not agree with Direct Initialization time' )
533
534	IF ( ln_trainc ) THEN
535	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
536	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
537	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
538	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
539	ENDIF
540
541	IF ( ln_dyninc ) THEN
542	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
543	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
544	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
545	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
546	ENDIF
547
548	IF ( ln_sshinc ) THEN
549	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
550	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
551	ENDIF
552
553	CALL iom_close( inum )
554
555	ENDIF
556	!
557	END SUBROUTINE asm_inc_init
558
559
560	SUBROUTINE calc_date( kit000, kt, kdate0, kdate )
561	!!----------------------------------------------------------------------
562	!! * ROUTINE calc_date *
563	!!
564	!! ** Purpose : Compute the calendar date YYYYMMDD at a given time step.
565	!!
566	!! ** Method : Compute the calendar date YYYYMMDD at a given time step.
567	!!
568	!! ** Action :
569	!!----------------------------------------------------------------------
570	INTEGER, INTENT(IN) :: kit000 ! Initial time step
571	INTEGER, INTENT(IN) :: kt ! Current time step referenced to kit000
572	INTEGER, INTENT(IN) :: kdate0 ! Initial date
573	INTEGER, INTENT(OUT) :: kdate ! Current date reference to kdate0
574	!
575	INTEGER :: iyea0 ! Initial year
576	INTEGER :: imon0 ! Initial month
577	INTEGER :: iday0 ! Initial day
578	INTEGER :: iyea ! Current year
579	INTEGER :: imon ! Current month
580	INTEGER :: iday ! Current day
581	INTEGER :: idaystp ! Number of days between initial and current date
582	INTEGER :: idaycnt ! Day counter
583
584	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
585
586	!-----------------------------------------------------------------------
587	! Compute the calendar date YYYYMMDD
588	!-----------------------------------------------------------------------
589
590	! Initial date
591	iyea0 = kdate0 / 10000
592	imon0 = ( kdate0 - ( iyea0 * 10000 ) ) / 100
593	iday0 = kdate0 - ( iyea0 * 10000 ) - ( imon0 * 100 )
594
595	! Check that kt >= kit000 - 1
596	IF ( kt < kit000 - 1 ) CALL ctl_stop( ' kt must be >= kit000 - 1')
597
598	! If kt = kit000 - 1 then set the date to the restart date
599	IF ( kt == kit000 - 1 ) THEN
600
601	kdate = ndastp
602	RETURN
603
604	ENDIF
605
606	! Compute the number of days from the initial date
607	idaystp = INT( REAL( kt - kit000 ) * rdt / 86400. )
608
609	iday = iday0
610	imon = imon0
611	iyea = iyea0
612	idaycnt = 0
613
614	CALL calc_month_len( iyea, imonth_len )
615
616	DO WHILE ( idaycnt < idaystp )
617	iday = iday + 1
618	IF ( iday > imonth_len(imon) ) THEN
619	iday = 1
620	imon = imon + 1
621	ENDIF
622	IF ( imon > 12 ) THEN
623	imon = 1
624	iyea = iyea + 1
625	CALL calc_month_len( iyea, imonth_len ) ! update month lengths
626	ENDIF
627	idaycnt = idaycnt + 1
628	END DO
629	!
630	kdate = iyea * 10000 + imon * 100 + iday
631	!
632	END SUBROUTINE
633
634
635	SUBROUTINE calc_month_len( iyear, imonth_len )
636	!!----------------------------------------------------------------------
637	!! * ROUTINE calc_month_len *
638	!!
639	!! ** Purpose : Compute the number of days in a months given a year.
640	!!
641	!! ** Method :
642	!!----------------------------------------------------------------------
643	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
644	INTEGER :: iyear !: year
645	!!----------------------------------------------------------------------
646	!
647	! length of the month of the current year (from nleapy, read in namelist)
648	IF ( nleapy < 2 ) THEN
649	imonth_len(:) = (/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
650	IF ( nleapy == 1 ) THEN ! we are using calendar with leap years
651	IF ( MOD(iyear, 4) == 0 .AND. ( MOD(iyear, 400) == 0 .OR. MOD(iyear, 100) /= 0 ) ) THEN
652	imonth_len(2) = 29
653	ENDIF
654	ENDIF
655	ELSE
656	imonth_len(:) = nleapy ! all months with nleapy days per year
657	ENDIF
658	!
659	END SUBROUTINE
660
661
662	SUBROUTINE tra_asm_inc( kt )
663	!!----------------------------------------------------------------------
664	!! * ROUTINE tra_asm_inc *
665	!!
666	!! ** Purpose : Apply the tracer (T and S) assimilation increments
667	!!
668	!! ** Method : Direct initialization or Incremental Analysis Updating
669	!!
670	!! ** Action :
671	!!----------------------------------------------------------------------
672	INTEGER, INTENT(IN) :: kt ! Current time step
673	!
674	INTEGER :: ji,jj,jk
675	INTEGER :: it
676	REAL(wp) :: zincwgt ! IAU weight for current time step
677	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
678	!!----------------------------------------------------------------------
679
680	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
681	! used to prevent the applied increments taking the temperature below the local freezing point
682
683	DO jk = 1, jpkm1
684	CALL eos_fzp( tsn(:,:,jk,jp_sal), fzptnz(:,:,jk), fsdept(:,:,jk) )
685	END DO
686
687	IF ( ln_asmiau ) THEN
688
689	!--------------------------------------------------------------------
690	! Incremental Analysis Updating
691	!--------------------------------------------------------------------
692
693	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
694
695	it = kt - nit000 + 1
696	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
697
698	IF(lwp) THEN
699	WRITE(numout,*)
700	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', kt,' with IAU weight = ', wgtiau(it)
701	WRITE(numout,*) '~~~~~~~~~~~~'
702	ENDIF
703
704	! Update the tracer tendencies
705	DO jk = 1, jpkm1
706	IF (ln_temnofreeze) THEN
707	! Do not apply negative increments if the temperature will fall below freezing
708	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
709	& tsn(:,:,jk,jp_tem) + tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
710	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
711	END WHERE
712	ELSE
713	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
714	ENDIF
715	IF (ln_salfix) THEN
716	! Do not apply negative increments if the salinity will fall below a specified
717	! minimum value salfixmin
718	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
719	& tsn(:,:,jk,jp_sal) + tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
720	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
721	END WHERE
722	ELSE
723	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
724	ENDIF
725	END DO
726
727	ENDIF
728
729	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
730	DEALLOCATE( t_bkginc )
731	DEALLOCATE( s_bkginc )
732	ENDIF
733
734
735	ELSEIF ( ln_asmdin ) THEN
736
737	!--------------------------------------------------------------------
738	! Direct Initialization
739	!--------------------------------------------------------------------
740
741	IF ( kt == nitdin_r ) THEN
742
743	neuler = 0 ! Force Euler forward step
744
745	! Initialize the now fields with the background + increment
746	IF (ln_temnofreeze) THEN
747	! Do not apply negative increments if the temperature will fall below freezing
748	WHERE( t_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
749	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
750	END WHERE
751	ELSE
752	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
753	ENDIF
754	IF (ln_salfix) THEN
755	! Do not apply negative increments if the salinity will fall below a specified
756	! minimum value salfixmin
757	WHERE( s_bkginc(:,:,:) > 0.0_wp .OR. tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
758	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
759	END WHERE
760	ELSE
761	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
762	ENDIF
763
764	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
765
766	CALL eos( tsb, rhd, rhop, gdept_0(:,:,:) ) ! Before potential and in situ densities
767	!!gm fabien
768	! CALL eos( tsb, rhd, rhop ) ! Before potential and in situ densities
769	!!gm
770
771
772	IF( ln_zps .AND. .NOT. lk_c1d .AND. .NOT. ln_isfcav) &
773	& CALL zps_hde ( kt, jpts, tsb, gtsu, gtsv, & ! Partial steps: before horizontal gradient
774	& rhd, gru , grv ) ! of t, s, rd at the last ocean level
775	IF( ln_zps .AND. .NOT. lk_c1d .AND. ln_isfcav) &
776	& CALL zps_hde_isf( nit000, jpts, tsb, gtsu, gtsv, & ! Partial steps for top cell (ISF)
777	& rhd, gru , grv , aru , arv , gzu , gzv , ge3ru , ge3rv , &
778	& gtui, gtvi, grui, grvi, arui, arvi, gzui, gzvi, ge3rui, ge3rvi ) ! of t, s, rd at the last ocean level
779
780	#if defined key_zdfkpp
781	CALL eos( tsn, rhd, fsdept_n(:,:,:) ) ! Compute rhd
782	!!gm fabien CALL eos( tsn, rhd ) ! Compute rhd
783	#endif
784
785	DEALLOCATE( t_bkginc )
786	DEALLOCATE( s_bkginc )
787	DEALLOCATE( t_bkg )
788	DEALLOCATE( s_bkg )
789	ENDIF
790	!
791	ENDIF
792	! Perhaps the following call should be in step
793	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
794	IF ( ln_sitinc ) CALL sit_asm_inc ( kt ) ! apply sea ice thickness increment
795	!
796	END SUBROUTINE tra_asm_inc
797
798
799	SUBROUTINE dyn_asm_inc( kt )
800	!!----------------------------------------------------------------------
801	!! * ROUTINE dyn_asm_inc *
802	!!
803	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
804	!!
805	!! ** Method : Direct initialization or Incremental Analysis Updating.
806	!!
807	!! ** Action :
808	!!----------------------------------------------------------------------
809	INTEGER, INTENT(IN) :: kt ! Current time step
810	!
811	INTEGER :: jk
812	INTEGER :: it
813	REAL(wp) :: zincwgt ! IAU weight for current time step
814	!!----------------------------------------------------------------------
815
816	IF ( ln_asmiau ) THEN
817
818	!--------------------------------------------------------------------
819	! Incremental Analysis Updating
820	!--------------------------------------------------------------------
821
822	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
823
824	it = kt - nit000 + 1
825	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
826
827	IF(lwp) THEN
828	WRITE(numout,*)
829	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', &
830	& kt,' with IAU weight = ', wgtiau(it)
831	WRITE(numout,*) '~~~~~~~~~~~~'
832	ENDIF
833
834	! Update the dynamic tendencies
835	DO jk = 1, jpkm1
836	ua(:,:,jk) = ua(:,:,jk) + u_bkginc(:,:,jk) * zincwgt
837	va(:,:,jk) = va(:,:,jk) + v_bkginc(:,:,jk) * zincwgt
838	END DO
839
840	IF ( kt == nitiaufin_r ) THEN
841	DEALLOCATE( u_bkginc )
842	DEALLOCATE( v_bkginc )
843	ENDIF
844
845	ENDIF
846
847	ELSEIF ( ln_asmdin ) THEN
848
849	!--------------------------------------------------------------------
850	! Direct Initialization
851	!--------------------------------------------------------------------
852
853	IF ( kt == nitdin_r ) THEN
854
855	neuler = 0 ! Force Euler forward step
856
857	! Initialize the now fields with the background + increment
858	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
859	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
860
861	ub(:,:,:) = un(:,:,:) ! Update before fields
862	vb(:,:,:) = vn(:,:,:)
863
864	DEALLOCATE( u_bkg )
865	DEALLOCATE( v_bkg )
866	DEALLOCATE( u_bkginc )
867	DEALLOCATE( v_bkginc )
868	ENDIF
869	!
870	ENDIF
871	!
872	END SUBROUTINE dyn_asm_inc
873
874
875	SUBROUTINE ssh_asm_inc( kt )
876	!!----------------------------------------------------------------------
877	!! * ROUTINE ssh_asm_inc *
878	!!
879	!! ** Purpose : Apply the sea surface height assimilation increment.
880	!!
881	!! ** Method : Direct initialization or Incremental Analysis Updating.
882	!!
883	!! ** Action :
884	!!----------------------------------------------------------------------
885	INTEGER, INTENT(IN) :: kt ! Current time step
886	!
887	INTEGER :: it
888	INTEGER :: jk
889	REAL(wp) :: zincwgt ! IAU weight for current time step
890	!!----------------------------------------------------------------------
891
892	IF ( ln_asmiau ) THEN
893
894	!--------------------------------------------------------------------
895	! Incremental Analysis Updating
896	!--------------------------------------------------------------------
897
898	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
899
900	it = kt - nit000 + 1
901	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
902
903	IF(lwp) THEN
904	WRITE(numout,*)
905	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
906	& kt,' with IAU weight = ', wgtiau(it)
907	WRITE(numout,*) '~~~~~~~~~~~~'
908	ENDIF
909
910	! Save the tendency associated with the IAU weighted SSH increment
911	! (applied in dynspg.*)
912	#if defined key_asminc
913	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
914	#endif
915	IF ( kt == nitiaufin_r ) THEN
916	DEALLOCATE( ssh_bkginc )
917	ENDIF
918
919	ELSE
920	#if defined key_asminc
921	ssh_iau(:,:) = 0.0
922	#endif
923	ENDIF
924
925	ELSEIF ( ln_asmdin ) THEN
926
927	!--------------------------------------------------------------------
928	! Direct Initialization
929	!--------------------------------------------------------------------
930
931	IF ( kt == nitdin_r ) THEN
932
933	neuler = 0 ! Force Euler forward step
934
935	! Initialize the now fields the background + increment
936	sshn(:,:) = ssh_bkg(:,:) + ssh_bkginc(:,:)
937
938	! Update before fields
939	sshb(:,:) = sshn(:,:)
940
941	IF( lk_vvl ) THEN
942	DO jk = 1, jpk
943	fse3t_b(:,:,jk) = fse3t_n(:,:,jk)
944	END DO
945	ENDIF
946
947	DEALLOCATE( ssh_bkg )
948	DEALLOCATE( ssh_bkginc )
949
950	ENDIF
951	!
952	ENDIF
953	!
954	END SUBROUTINE ssh_asm_inc
955
956	SUBROUTINE sit_asm_inc( kt, kindic )
957	!!----------------------------------------------------------------------
958	!! * ROUTINE sit_asm_inc *
959	!!
960	!! ** Purpose : Apply the sea ice thickness assimilation increment.
961	!!
962	!! ** Method : Direct initialization or Incremental Analysis Updating.
963	!!
964	!! ** Action :
965	!!
966	!!----------------------------------------------------------------------
967	IMPLICIT NONE
968	!
969	INTEGER, INTENT(in) :: kt ! Current time step
970	INTEGER, INTENT(in), OPTIONAL :: kindic ! flag for disabling the deallocation
971	!
972	INTEGER :: it
973	REAL(wp) :: zincwgt ! IAU weight for current time step
974	! #if defined key_lim2
975	! REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
976	! REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
977	! !!THICKNESS INCS NOT SET UP FOR LIM
978	! #endif
979	!!----------------------------------------------------------------------
980
981	IF ( ln_asmiau ) THEN
982
983	!--------------------------------------------------------------------
984	! Incremental Analysis Updating
985	!--------------------------------------------------------------------
986
987	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
988
989	it = kt - nit000 + 1
990	zincwgt = wgtiau(it) ! IAU weight for the current time step
991	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
992
993	IF(lwp) THEN
994	WRITE(numout,*)
995	WRITE(numout,*) 'sit_asm_inc : sea ice thick IAU at time step = ', &
996	& kt,' with IAU weight = ', wgtiau(it)
997	WRITE(numout,*) '~~~~~~~~~~~~'
998	ENDIF
999
1000	! Sea-ice : LIM-3 case (to add)
1001
1002	! #if defined key_lim2
1003	! ! Sea-ice : LIM-2 case (to add if needed)
1004	! zofrld (:,:) = frld(:,:)
1005	! zohicif(:,:) = hicif(:,:)
1006	! !
1007	! frld = MIN( MAX( frld (:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1008	! pfrld = MIN( MAX( pfrld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1009	! fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1010	! !
1011	! zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1012	! !
1013	! ! Nudge sea ice depth to bring it up to a required minimum depth
1014	! WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1015	! zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1016	! ELSEWHERE
1017	! zhicifinc(:,:) = 0.0_wp
1018	! END WHERE
1019	! !
1020	! ! nudge ice depth
1021	! hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1022	! phicif(:,:) = phicif(:,:) + zhicifinc(:,:)
1023	! !
1024	! ! seaice salinity balancing (to add)
1025	! #endif
1026
1027	#if defined key_cice && defined key_asminc
1028	! Sea-ice thickness : CICE case. Pass ice thickness increment tendency into CICE
1029	ndsit_da(:,:) = sit_bkginc(:,:) * zincwgt / rdt
1030	#endif
1031
1032	IF ( kt == nitiaufin_r ) THEN
1033	DEALLOCATE( sit_bkginc )
1034	ENDIF
1035
1036	ELSE
1037
1038	#if defined key_cice && defined key_asminc
1039	! Sea-ice thickness : CICE case. Zero ice increment tendency into CICE
1040	ndsit_da(:,:) = 0.0_wp
1041	#endif
1042
1043	ENDIF
1044
1045	ELSEIF ( ln_asmdin ) THEN
1046
1047	!--------------------------------------------------------------------
1048	! Direct Initialization
1049	!--------------------------------------------------------------------
1050
1051	IF ( kt == nitdin_r ) THEN
1052
1053	neuler = 0 ! Force Euler forward step
1054
1055	! Sea-ice : LIM-3 case (to add)
1056
1057	! #if defined key_lim2
1058	! ! Sea-ice : LIM-2 case (add if needed)
1059	! zofrld(:,:)=frld(:,:)
1060	! zohicif(:,:)=hicif(:,:)
1061	! !
1062	! ! Initialize the now fields the background + increment
1063	! frld (:,:) = MIN( MAX( frld(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
1064	! pfrld(:,:) = frld(:,:)
1065	! fr_i (:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1066	! zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1067	! !
1068	! ! Nudge sea ice depth to bring it up to a required minimum depth
1069	! WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1070	! zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1071	! ELSEWHERE
1072	! zhicifinc(:,:) = 0.0_wp
1073	! END WHERE
1074	! !
1075	! ! nudge ice depth
1076	! hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1077	! phicif(:,:) = phicif(:,:)
1078	! !
1079	! ! seaice salinity balancing (to add)
1080	! #endif
1081
1082	#if defined key_cice && defined key_asminc
1083	! Sea-ice thickness : CICE case. Pass ice thickness increment tendency into CICE
1084	ndsit_da(:,:) = sit_bkginc(:,:) / rdt
1085	#endif
1086	IF ( .NOT. PRESENT(kindic) ) THEN
1087	DEALLOCATE( sit_bkginc )
1088	END IF
1089
1090	ELSE
1091
1092	#if defined key_cice && defined key_asminc
1093	! Sea-ice thicnkness : CICE case. Zero ice thickness increment tendency into CICE
1094	ndsit_da(:,:) = 0.0_wp
1095	#endif
1096
1097	ENDIF
1098
1099	!#if defined defined key_lim2 \|\| defined key_cice
1100	!
1101	! IF (ln_seaicebal ) THEN
1102	! !! balancing salinity increments
1103	! !! simple case from limflx.F90 (doesn't include a mass flux)
1104	! !! assumption is that as ice concentration is reduced or increased
1105	! !! the snow and ice depths remain constant
1106	! !! note that snow is being created where ice concentration is being increased
1107	! !! - could be more sophisticated and
1108	! !! not do this (but would need to alter h_snow)
1109	!
1110	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
1111	!
1112	! DO jj = 1, jpj
1113	! DO ji = 1, jpi
1114	! ! calculate change in ice and snow mass per unit area
1115	! ! positive values imply adding salt to the ocean (results from ice formation)
1116	! ! fwf : ice formation and melting
1117	!
1118	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
1119	!
1120	! ! change salinity down to mixed layer depth
1121	! mld=hmld_kara(ji,jj)
1122	!
1123	! ! prevent small mld
1124	! ! less than 10m can cause salinity instability
1125	! IF (mld < 10) mld=10
1126	!
1127	! ! set to bottom of a level
1128	! DO jk = jpk-1, 2, -1
1129	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
1130	! mld=gdepw(ji,jj,jk+1)
1131	! jkmax=jk
1132	! ENDIF
1133	! ENDDO
1134	!
1135	! ! avoid applying salinity balancing in shallow water or on land
1136	! !
1137	!
1138	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
1139	!
1140	! dsal_ocn=0.0_wp
1141	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
1142	!
1143	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
1144	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
1145	!
1146	! ! put increments in for levels in the mixed layer
1147	! ! but prevent salinity below a threshold value
1148	!
1149	! DO jk = 1, jkmax
1150	!
1151	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
1152	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
1153	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
1154	! ENDIF
1155	!
1156	! ENDDO
1157	!
1158	! ! ! salt exchanges at the ice/ocean interface
1159	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
1160	! !
1161	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
1162	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
1163	! !!
1164	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
1165	! !! ! E-P (kg m-2 s-2)
1166	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
1167	! ENDDO !ji
1168	! ENDDO !jj!
1169	!
1170	! ENDIF !ln_seaicebal
1171	!
1172	!#endif
1173
1174	ENDIF
1175
1176	END SUBROUTINE sit_asm_inc
1177
1178	SUBROUTINE seaice_asm_inc( kt, kindic )
1179	!!----------------------------------------------------------------------
1180	!! * ROUTINE seaice_asm_inc *
1181	!!
1182	!! ** Purpose : Apply the sea ice concentration assimilation increment.
1183	!!
1184	!! ** Method : Direct initialization or Incremental Analysis Updating.
1185	!!
1186	!! ** Action :
1187	!!
1188	!!----------------------------------------------------------------------
1189	IMPLICIT NONE
1190	!
1191	INTEGER, INTENT(in) :: kt ! Current time step
1192	INTEGER, INTENT(in), OPTIONAL :: kindic ! flag for disabling the deallocation
1193	!
1194	INTEGER :: it
1195	REAL(wp) :: zincwgt ! IAU weight for current time step
1196	#if defined key_lim2
1197	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
1198	REAL(wp) :: zhicifmin = 0.5_wp ! ice minimum depth in metres
1199	#endif
1200	!!----------------------------------------------------------------------
1201
1202	IF ( ln_asmiau ) THEN
1203
1204	!--------------------------------------------------------------------
1205	! Incremental Analysis Updating
1206	!--------------------------------------------------------------------
1207
1208	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
1209
1210	it = kt - nit000 + 1
1211	zincwgt = wgtiau(it) ! IAU weight for the current time step
1212	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
1213
1214	IF(lwp) THEN
1215	WRITE(numout,*)
1216	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', &
1217	& kt,' with IAU weight = ', wgtiau(it)
1218	WRITE(numout,*) '~~~~~~~~~~~~'
1219	ENDIF
1220
1221	! Sea-ice : LIM-3 case (to add)
1222
1223	#if defined key_lim2
1224	! Sea-ice : LIM-2 case
1225	zofrld (:,:) = frld(:,:)
1226	zohicif(:,:) = hicif(:,:)
1227	!
1228	frld = MIN( MAX( frld (:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1229	pfrld = MIN( MAX( pfrld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1230	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1231	!
1232	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1233	!
1234	! Nudge sea ice depth to bring it up to a required minimum depth
1235	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1236	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1237	ELSEWHERE
1238	zhicifinc(:,:) = 0.0_wp
1239	END WHERE
1240	!
1241	! nudge ice depth
1242	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1243	phicif(:,:) = phicif(:,:) + zhicifinc(:,:)
1244	!
1245	! seaice salinity balancing (to add)
1246	#endif
1247
1248	#if defined key_cice && defined key_asminc
1249	! Sea-ice : CICE case. Pass ice increment tendency into CICE
1250	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
1251	#endif
1252
1253	IF ( kt == nitiaufin_r ) THEN
1254	DEALLOCATE( seaice_bkginc )
1255	ENDIF
1256
1257	ELSE
1258
1259	#if defined key_cice && defined key_asminc
1260	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1261	ndaice_da(:,:) = 0.0_wp
1262	#endif
1263
1264	ENDIF
1265
1266	ELSEIF ( ln_asmdin ) THEN
1267
1268	!--------------------------------------------------------------------
1269	! Direct Initialization
1270	!--------------------------------------------------------------------
1271
1272	IF ( kt == nitdin_r ) THEN
1273
1274	neuler = 0 ! Force Euler forward step
1275
1276	! Sea-ice : LIM-3 case (to add)
1277
1278	#if defined key_lim2
1279	! Sea-ice : LIM-2 case.
1280	zofrld(:,:)=frld(:,:)
1281	zohicif(:,:)=hicif(:,:)
1282	!
1283	! Initialize the now fields the background + increment
1284	frld (:,:) = MIN( MAX( frld(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
1285	pfrld(:,:) = frld(:,:)
1286	fr_i (:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1287	zseaicendg(:,:) = zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1288	!
1289	! Nudge sea ice depth to bring it up to a required minimum depth
1290	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1291	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1292	ELSEWHERE
1293	zhicifinc(:,:) = 0.0_wp
1294	END WHERE
1295	!
1296	! nudge ice depth
1297	hicif (:,:) = hicif (:,:) + zhicifinc(:,:)
1298	phicif(:,:) = phicif(:,:)
1299	!
1300	! seaice salinity balancing (to add)
1301	#endif
1302
1303	#if defined key_cice && defined key_asminc
1304	! Sea-ice : CICE case. Pass ice increment tendency into CICE
1305	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
1306	#endif
1307	IF ( .NOT. PRESENT(kindic) ) THEN
1308	DEALLOCATE( seaice_bkginc )
1309	END IF
1310
1311	ELSE
1312
1313	#if defined key_cice && defined key_asminc
1314	! Sea-ice : CICE case. Zero ice increment tendency into CICE
1315	ndaice_da(:,:) = 0.0_wp
1316	#endif
1317
1318	ENDIF
1319
1320	!#if defined defined key_lim2 \|\| defined key_cice
1321	!
1322	! IF (ln_seaicebal ) THEN
1323	! !! balancing salinity increments
1324	! !! simple case from limflx.F90 (doesn't include a mass flux)
1325	! !! assumption is that as ice concentration is reduced or increased
1326	! !! the snow and ice depths remain constant
1327	! !! note that snow is being created where ice concentration is being increased
1328	! !! - could be more sophisticated and
1329	! !! not do this (but would need to alter h_snow)
1330	!
1331	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
1332	!
1333	! DO jj = 1, jpj
1334	! DO ji = 1, jpi
1335	! ! calculate change in ice and snow mass per unit area
1336	! ! positive values imply adding salt to the ocean (results from ice formation)
1337	! ! fwf : ice formation and melting
1338	!
1339	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
1340	!
1341	! ! change salinity down to mixed layer depth
1342	! mld=hmld_kara(ji,jj)
1343	!
1344	! ! prevent small mld
1345	! ! less than 10m can cause salinity instability
1346	! IF (mld < 10) mld=10
1347	!
1348	! ! set to bottom of a level
1349	! DO jk = jpk-1, 2, -1
1350	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
1351	! mld=gdepw(ji,jj,jk+1)
1352	! jkmax=jk
1353	! ENDIF
1354	! ENDDO
1355	!
1356	! ! avoid applying salinity balancing in shallow water or on land
1357	! !
1358	!
1359	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
1360	!
1361	! dsal_ocn=0.0_wp
1362	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
1363	!
1364	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
1365	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
1366	!
1367	! ! put increments in for levels in the mixed layer
1368	! ! but prevent salinity below a threshold value
1369	!
1370	! DO jk = 1, jkmax
1371	!
1372	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
1373	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
1374	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
1375	! ENDIF
1376	!
1377	! ENDDO
1378	!
1379	! ! ! salt exchanges at the ice/ocean interface
1380	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
1381	! !
1382	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
1383	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
1384	! !!
1385	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
1386	! !! ! E-P (kg m-2 s-2)
1387	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
1388	! ENDDO !ji
1389	! ENDDO !jj!
1390	!
1391	! ENDIF !ln_seaicebal
1392	!
1393	!#endif
1394
1395	ENDIF
1396
1397	END SUBROUTINE seaice_asm_inc
1398
1399	!!======================================================================
1400	END MODULE asminc

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