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asminc.F90 @ 7367

Last change on this file since 7367 was 7367, checked in by deazer, 7 years ago
Contains merged code for CO5 reference.
File size: 52.2 KB

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1	MODULE asminc
2	!!======================================================================
3	!! * MODULE asminc *
4	!! Assimilation increment : Apply an increment generated by data
5	!! assimilation
6	!!======================================================================
7	!! History : ! 2007-03 (M. Martin) Met Office version
8	!! ! 2007-04 (A. Weaver) calc_date original code
9	!! ! 2007-04 (A. Weaver) Merge with OPAVAR/NEMOVAR
10	!! NEMO 3.3 ! 2010-05 (D. Lea) Update to work with NEMO v3.2
11	!! - ! 2010-05 (D. Lea) add calc_month_len routine based on day_init
12	!! 3.4 ! 2012-10 (A. Weaver and K. Mogensen) Fix for direct initialization
13	!!----------------------------------------------------------------------
14
15	!!----------------------------------------------------------------------
16	!! 'key_asminc' : Switch on the assimilation increment interface
17	!!----------------------------------------------------------------------
18	!! asm_inc_init : Initialize the increment arrays and IAU weights
19	!! calc_date : Compute the calendar date YYYYMMDD on a given step
20	!! tra_asm_inc : Apply the tracer (T and S) increments
21	!! dyn_asm_inc : Apply the dynamic (u and v) increments
22	!! ssh_asm_inc : Apply the SSH increment
23	!! seaice_asm_inc : Apply the seaice increment
24	!!----------------------------------------------------------------------
25	USE wrk_nemo ! Memory Allocation
26	USE par_oce ! Ocean space and time domain variables
27	USE dom_oce ! Ocean space and time domain
28	USE oce ! Dynamics and active tracers defined in memory
29	USE ldfdyn_oce ! ocean dynamics: lateral physics
30	USE eosbn2 ! Equation of state - in situ and potential density
31	USE zpshde ! Partial step : Horizontal Derivative
32	USE iom ! Library to read input files
33	USE asmpar ! Parameters for the assmilation interface
34	USE c1d ! 1D initialization
35	USE in_out_manager ! I/O manager
36	USE lib_mpp ! MPP library
37	#if defined key_lim3 \|\| defined key_lim2 \|\| defined key_cice
38	#if defined key_lim3
39	USE ice_3, ONLY : & ! LIM Ice model variables ()
40	& frld, pfrld, hicif, hsnif, phicif
41	USE sbc_oce, ONLY : &
42	& fr_i ! ice fraction
43	#endif
44	#if defined key_lim2
45	USE ice_2, ONLY : & ! LIM Ice model variables
46	& frld, pfrld, hicif, hsnif, phicif
47	USE sbc_oce, ONLY : &
48	& fr_i ! ice fraction
49	#endif
50	#if defined key_cice
51	USE sbc_oce, ONLY : &
52	& fr_i ! ice fraction
53	USE sbc_ice, ONLY : & ! CICE Ice model variables
54	& naicet, ndaice_da, nfresh_da, nfsalt_da, nTf
55	USE ice_constants, only: Lfresh, rhoi,rhos ! for updating ice and snow enthalphy
56	! USE ice_therm_itd, only: hfrazilmin ! thickness at new ice points
57	USE ice_domain_size, only: ncat,ntilyr,ntslyr
58	#endif
59	USE phycst, ONLY : & ! Physical Ice variables
60	& soce, sice, rhoic, rhosn, rday
61	#endif
62	USE sbc_oce ! Surface boundary condition variables.
63
64	USE eosbn2, only: tfreez
65
66	USE zdfmxl, ONLY : &
67	& hmld_tref, &
68	#if defined key_karaml
69	& hmld_kara, &
70	#endif
71	& hmld, &
72	& hmlp
73
74	#if defined key_bdy
75	USE bdy_oce, ONLY: bdytmask
76	#endif
77	USE histcom
78
79	IMPLICIT NONE
80	PRIVATE
81
82	PUBLIC asm_inc_init !: Initialize the increment arrays and IAU weights
83	PUBLIC calc_date !: Compute the calendar date YYYYMMDD on a given step
84	PUBLIC tra_asm_inc !: Apply the tracer (T and S) increments
85	PUBLIC dyn_asm_inc !: Apply the dynamic (u and v) increments
86	PUBLIC ssh_asm_inc !: Apply the SSH increment
87	PUBLIC seaice_asm_inc !: Apply the seaice increment
88
89	#if defined key_asminc
90	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .TRUE. !: Logical switch for assimilation increment interface
91	#else
92	LOGICAL, PUBLIC, PARAMETER :: lk_asminc = .FALSE. !: No assimilation increments
93	#endif
94	LOGICAL, PUBLIC :: ln_bkgwri = .FALSE. !: No output of the background state fields
95	LOGICAL, PUBLIC :: ln_trjwri = .FALSE. !: No output of the state trajectory fields
96	LOGICAL, PUBLIC :: ln_asmiau = .FALSE. !: No applying forcing with an assimilation increment
97	LOGICAL, PUBLIC :: ln_asmdin = .FALSE. !: No direct initialization
98	LOGICAL, PUBLIC :: ln_trainc = .FALSE. !: No tracer (T and S) assimilation increments
99	LOGICAL, PUBLIC :: ln_dyninc = .FALSE. !: No dynamics (u and v) assimilation increments
100	LOGICAL, PUBLIC :: ln_sshinc = .FALSE. !: No sea surface height assimilation increment
101	LOGICAL, PUBLIC :: ln_seaiceinc = .FALSE. !: No sea ice concentration increment
102	LOGICAL, PUBLIC :: ln_salfix = .FALSE. !: Apply minimum salinity check
103	LOGICAL, PUBLIC :: ln_temnofreeze = .FALSE. !: Don't allow the temperature to drop below freezing
104	INTEGER, PUBLIC :: nn_divdmp = 0 !: Apply divergence damping filter nn_divdmp times
105
106	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkg , s_bkg !: Background temperature and salinity
107	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkg , v_bkg !: Background u- & v- velocity components
108	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: t_bkginc, s_bkginc !: Increment to the background T & S
109	REAL(wp), PUBLIC, DIMENSION(:,:,:), ALLOCATABLE :: u_bkginc, v_bkginc !: Increment to the u- & v-components
110	REAL(wp), PUBLIC, DIMENSION(:) , ALLOCATABLE :: wgtiau !: IAU weights for each time step
111	#if defined key_asminc
112	REAL(wp), PUBLIC, DIMENSION(:,:), ALLOCATABLE :: ssh_iau !: IAU-weighted sea surface height increment
113	#endif
114	! !!! time steps relative to the cycle interval [0,nitend-nit000-1]
115	INTEGER , PUBLIC :: nitbkg !: Time step of the background state used in the Jb term
116	INTEGER , PUBLIC :: nitdin !: Time step of the background state for direct initialization
117	INTEGER , PUBLIC :: nitiaustr !: Time step of the start of the IAU interval
118	INTEGER , PUBLIC :: nitiaufin !: Time step of the end of the IAU interval
119	!
120	INTEGER , PUBLIC :: niaufn !: Type of IAU weighing function: = 0 Constant weighting
121	! !: = 1 Linear hat-like, centred in middle of IAU interval
122	REAL(wp), PUBLIC :: salfixmin !: Ensure that the salinity is larger than this value if (ln_salfix)
123
124	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: ssh_bkg, ssh_bkginc ! Background sea surface height and its increment
125	REAL(wp), DIMENSION(:,:), ALLOCATABLE :: seaice_bkginc ! Increment to the background sea ice conc
126
127	INTEGER :: mld_choice = 4 !: choice of mld criteria to use
128	!: 1) turbocline depth
129	!: 2) surface to 0.001 kg/m^3 change
130	!: 3) Kara MLD
131	!: 4) Temperature criteria.
132
133	!! * Substitutions
134	# include "domzgr_substitute.h90"
135	# include "ldfdyn_substitute.h90"
136	# include "vectopt_loop_substitute.h90"
137
138	!!----------------------------------------------------------------------
139	!! NEMO/OPA 3.3 , NEMO Consortium (2010)
140	!! $Id$
141	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
142	!!----------------------------------------------------------------------
143	CONTAINS
144
145	SUBROUTINE asm_inc_init
146	!!----------------------------------------------------------------------
147	!! * ROUTINE asm_inc_init *
148	!!
149	!! ** Purpose : Initialize the assimilation increment and IAU weights.
150	!!
151	!! ** Method : Initialize the assimilation increment and IAU weights.
152	!!
153	!! ** Action :
154	!!----------------------------------------------------------------------
155	!!
156	!!
157	INTEGER :: ji,jj,jk
158	INTEGER :: jt
159	INTEGER :: imid
160	INTEGER :: inum
161	INTEGER :: iiauper ! Number of time steps in the IAU period
162	INTEGER :: icycper ! Number of time steps in the cycle
163	INTEGER :: iitend_date ! Date YYYYMMDD of final time step
164	INTEGER :: iitbkg_date ! Date YYYYMMDD of background time step for Jb term
165	INTEGER :: iitdin_date ! Date YYYYMMDD of background time step for DI
166	INTEGER :: iitiaustr_date ! Date YYYYMMDD of IAU interval start time step
167	INTEGER :: iitiaufin_date ! Date YYYYMMDD of IAU interval final time step
168
169	REAL(wp) :: znorm ! Normalization factor for IAU weights
170	REAL(wp) :: ztotwgt ! Value of time-integrated IAU weights
171	! (should be equal to one)
172	REAL(wp) :: z_inc_dateb ! Start date of interval on which increment is valid
173	REAL(wp) :: z_inc_datef ! End date of interval on which increment is valid
174	REAL(wp) :: zdate_bkg ! Date in background state file for DI
175	REAL(wp) :: zdate_inc ! Time axis in increments file
176
177	REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: &
178	& t_bkginc_2d !file for reading in 2D
179	!temperature increments
180	REAL(wp), ALLOCATABLE, DIMENSION(:,:) :: &
181	& z_mld !Mixed layer depth
182
183	REAL(wp), POINTER, DIMENSION(:,:) :: hdiv
184
185	!!
186	NAMELIST/nam_asminc/ ln_bkgwri, ln_trjwri, &
187	& ln_trainc, ln_dyninc, ln_sshinc, &
188	& ln_asmdin, ln_asmiau, &
189	& nitbkg, nitdin, nitiaustr, nitiaufin, niaufn, &
190	& nittrjfrq, ln_salfix, salfixmin, &
191	& nn_divdmp, mld_choice
192	!!----------------------------------------------------------------------
193
194	!-----------------------------------------------------------------------
195	! Read Namelist nam_asminc : assimilation increment interface
196	!-----------------------------------------------------------------------
197
198	! Set default values
199	ln_bkgwri = .FALSE.
200	ln_trjwri = .FALSE.
201	ln_trainc = .FALSE.
202	ln_dyninc = .FALSE.
203	ln_sshinc = .FALSE.
204	ln_seaiceinc = .FALSE.
205	ln_asmdin = .FALSE.
206	ln_asmiau = .TRUE.
207	ln_salfix = .FALSE.
208	ln_temnofreeze = .FALSE.
209	salfixmin = -9999
210	nitbkg = 0
211	nitdin = 0
212	nitiaustr = 1
213	nitiaufin = 150 ! = 10 days with ORCA2
214	niaufn = 0
215	nittrjfrq = 1
216
217	REWIND ( numnam )
218	READ ( numnam, nam_asminc )
219
220	! Set the data time for diagnostics to the end of the IAU period
221	! and multiply by the timestep to get seconds from start of run
222	data_time = rdt * nitiaufin
223
224	IF( ln_sco .AND. (ln_sshinc .OR. ln_seaiceinc .OR. ln_asmdin &
225	& .OR. ln_dyninc ) )THEN
226	CALL ctl_warn("Only SST assimilation currently supported in "//&
227	& "s-coordinates")
228	ln_sshinc = .FALSE.
229	ln_seaiceinc = .FALSE.
230	ln_asmdin = .FALSE.
231	ln_dyninc = .FALSE.
232	ENDIF
233
234	! Control print
235	IF(lwp) THEN
236	WRITE(numout,*)
237	WRITE(numout,*) 'asm_inc_init : Assimilation increment initialization :'
238	WRITE(numout,*) '~~~~~~~~~~~~'
239	WRITE(numout,*) ' Namelist namasm : set assimilation increment parameters'
240	WRITE(numout,*) ' Logical switch for writing out background state ln_bkgwri = ', ln_bkgwri
241	WRITE(numout,*) ' Logical switch for writing out state trajectory ln_trjwri = ', ln_trjwri
242	WRITE(numout,*) ' Logical switch for applying tracer increments ln_trainc = ', ln_trainc
243	WRITE(numout,*) ' Logical switch for applying velocity increments ln_dyninc = ', ln_dyninc
244	WRITE(numout,*) ' Logical switch for applying SSH increments ln_sshinc = ', ln_sshinc
245	WRITE(numout,*) ' Logical switch for Direct Initialization (DI) ln_asmdin = ', ln_asmdin
246	WRITE(numout,*) ' Logical switch for applying sea ice increments ln_seaiceinc = ', ln_seaiceinc
247	WRITE(numout,*) ' Logical switch for Incremental Analysis Updating (IAU) ln_asmiau = ', ln_asmiau
248	WRITE(numout,*) ' Timestep of background in [0,nitend-nit000-1] nitbkg = ', nitbkg
249	WRITE(numout,*) ' Timestep of background for DI in [0,nitend-nit000-1] nitdin = ', nitdin
250	WRITE(numout,*) ' Timestep of start of IAU interval in [0,nitend-nit000-1] nitiaustr = ', nitiaustr
251	WRITE(numout,*) ' Timestep of end of IAU interval in [0,nitend-nit000-1] nitiaufin = ', nitiaufin
252	WRITE(numout,*) ' Type of IAU weighting function niaufn = ', niaufn
253	WRITE(numout,*) ' Frequency of trajectory output for 4D-VAR nittrjfrq = ', nittrjfrq
254	WRITE(numout,*) ' Logical switch for ensuring that the sa > salfixmin ln_salfix = ', ln_salfix
255	WRITE(numout,*) ' Minimum salinity after applying the increments salfixmin = ', salfixmin
256	ENDIF
257
258	nitbkg_r = nitbkg + nit000 - 1 ! Background time referenced to nit000
259	nitdin_r = nitdin + nit000 - 1 ! Background time for DI referenced to nit000
260	nitiaustr_r = nitiaustr + nit000 - 1 ! Start of IAU interval referenced to nit000
261	nitiaufin_r = nitiaufin + nit000 - 1 ! End of IAU interval referenced to nit000
262
263	iiauper = nitiaufin_r - nitiaustr_r + 1 ! IAU interval length
264	icycper = nitend - nit000 + 1 ! Cycle interval length
265
266	! Date of final time step
267	CALL calc_date( nit000, nitend, ndate0, iitend_date )
268
269	! Background time for Jb referenced to ndate0
270	CALL calc_date( nit000, nitbkg_r, ndate0, iitbkg_date )
271
272	! Background time for DI referenced to ndate0
273	CALL calc_date( nit000, nitdin_r, ndate0, iitdin_date )
274
275	! IAU start time referenced to ndate0
276	CALL calc_date( nit000, nitiaustr_r, ndate0, iitiaustr_date )
277
278	! IAU end time referenced to ndate0
279	CALL calc_date( nit000, nitiaufin_r, ndate0, iitiaufin_date )
280
281	IF(lwp) THEN
282	WRITE(numout,*)
283	WRITE(numout,*) ' Time steps referenced to current cycle:'
284	WRITE(numout,*) ' iitrst = ', nit000 - 1
285	WRITE(numout,*) ' nit000 = ', nit000
286	WRITE(numout,*) ' nitend = ', nitend
287	WRITE(numout,*) ' nitbkg_r = ', nitbkg_r
288	WRITE(numout,*) ' nitdin_r = ', nitdin_r
289	WRITE(numout,*) ' nitiaustr_r = ', nitiaustr_r
290	WRITE(numout,*) ' nitiaufin_r = ', nitiaufin_r
291	WRITE(numout,*) ' nittrjfrq = ', nittrjfrq
292	WRITE(numout,*)
293	WRITE(numout,*) ' Dates referenced to current cycle:'
294	WRITE(numout,*) ' ndastp = ', ndastp
295	WRITE(numout,*) ' ndate0 = ', ndate0
296	WRITE(numout,*) ' iitend_date = ', iitend_date
297	WRITE(numout,*) ' iitbkg_date = ', iitbkg_date
298	WRITE(numout,*) ' iitdin_date = ', iitdin_date
299	WRITE(numout,*) ' iitiaustr_date = ', iitiaustr_date
300	WRITE(numout,*) ' iitiaufin_date = ', iitiaufin_date
301	ENDIF
302
303	IF ( nacc /= 0 ) &
304	& CALL ctl_stop( ' nacc /= 0 and key_asminc :', &
305	& ' Assimilation increments have only been implemented', &
306	& ' for synchronous time stepping' )
307
308	IF ( ( ln_asmdin ).AND.( ln_asmiau ) ) &
309	& CALL ctl_stop( ' ln_asmdin and ln_asmiau :', &
310	& ' Choose Direct Initialization OR Incremental Analysis Updating')
311
312	IF ( ( ( .NOT. ln_asmdin ).AND.( .NOT. ln_asmiau ) ) &
313	.AND.( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ) .OR. ( ln_seaiceinc) )) &
314	& CALL ctl_stop( ' One or more of ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc is set to .true.', &
315	& ' but ln_asmdin and ln_asmiau are both set to .false. :', &
316	& ' Inconsistent options')
317
318	IF ( ( ln_bkgwri ).AND.( ( ln_asmdin ).OR.( ln_asmiau ) ) ) &
319	& CALL ctl_stop( ' ln_bkgwri and either ln_asmdin or ln_asmiau are set to .true.:', &
320	& ' The background state must be written before applying the increments')
321
322	IF ( ( niaufn /= 0 ).AND.( niaufn /= 1 ) ) &
323	& CALL ctl_stop( ' niaufn /= 0 or niaufn /=1 :', &
324	& ' Type IAU weighting function is invalid')
325
326	IF ( ( .NOT. ln_trainc ).AND.( .NOT. ln_dyninc ).AND.( .NOT. ln_sshinc ).AND.( .NOT. ln_seaiceinc ) &
327	& ) &
328	& CALL ctl_warn( ' ln_trainc, ln_dyninc, ln_sshinc and ln_seaiceinc are set to .false. :', &
329	& ' The assimilation increments are not applied')
330
331	IF ( ( ln_asmiau ).AND.( nitiaustr == nitiaufin ) ) &
332	& CALL ctl_stop( ' nitiaustr = nitiaufin :', &
333	& ' IAU interval is of zero length')
334
335	IF ( ( ln_asmiau ).AND.( ( nitiaustr_r < nit000 ).OR.( nitiaufin_r > nitend ) ) ) &
336	& CALL ctl_stop( ' nitiaustr or nitiaufin :', &
337	& ' IAU starting or final time step is outside the cycle interval', &
338	& ' Valid range nit000 to nitend')
339
340	IF ( ( nitbkg_r < nit000 - 1 ).OR.( nitbkg_r > nitend ) ) &
341	& CALL ctl_stop( ' nitbkg :', &
342	& ' Background time step is outside the cycle interval')
343
344	IF ( ( nitdin_r < nit000 - 1 ).OR.( nitdin_r > nitend ) ) &
345	& CALL ctl_stop( ' nitdin :', &
346	& ' Background time step for Direct Initialization is outside', &
347	& ' the cycle interval')
348
349	IF ( nstop > 0 ) RETURN ! if there are any errors then go no further
350
351	!--------------------------------------------------------------------
352	! Initialize the Incremental Analysis Updating weighting function
353	!--------------------------------------------------------------------
354
355	IF ( ln_asmiau ) THEN
356
357	ALLOCATE( wgtiau( icycper ) )
358
359	wgtiau(:) = 0.0
360
361	IF ( niaufn == 0 ) THEN
362
363	!---------------------------------------------------------
364	! Constant IAU forcing
365	!---------------------------------------------------------
366
367	DO jt = 1, iiauper
368	wgtiau(jt+nitiaustr-1) = 1.0 / REAL( iiauper )
369	END DO
370
371	ELSEIF ( niaufn == 1 ) THEN
372
373	!---------------------------------------------------------
374	! Linear hat-like, centred in middle of IAU interval
375	!---------------------------------------------------------
376
377	! Compute the normalization factor
378	znorm = 0.0
379	IF ( MOD( iiauper, 2 ) == 0 ) THEN ! Even number of time steps in IAU interval
380	imid = iiauper / 2
381	DO jt = 1, imid
382	znorm = znorm + REAL( jt )
383	END DO
384	znorm = 2.0 * znorm
385	ELSE ! Odd number of time steps in IAU interval
386	imid = ( iiauper + 1 ) / 2
387	DO jt = 1, imid - 1
388	znorm = znorm + REAL( jt )
389	END DO
390	znorm = 2.0 * znorm + REAL( imid )
391	ENDIF
392	znorm = 1.0 / znorm
393
394	DO jt = 1, imid - 1
395	wgtiau(jt+nitiaustr-1) = REAL( jt ) * znorm
396	END DO
397	DO jt = imid, iiauper
398	wgtiau(jt+nitiaustr-1) = REAL( iiauper - jt + 1 ) * znorm
399	END DO
400
401	ENDIF
402
403	! Test that the integral of the weights over the weighting interval equals 1
404	IF(lwp) THEN
405	WRITE(numout,*)
406	WRITE(numout,*) 'asm_inc_init : IAU weights'
407	WRITE(numout,*) '~~~~~~~~~~~~'
408	WRITE(numout,*) ' time step IAU weight'
409	WRITE(numout,*) ' ========= ====================='
410	ztotwgt = 0.0
411	DO jt = 1, icycper
412	ztotwgt = ztotwgt + wgtiau(jt)
413	WRITE(numout,*) ' ', jt, ' ', wgtiau(jt)
414	END DO
415	WRITE(numout,*) ' ==================================='
416	WRITE(numout,*) ' Time-integrated weight = ', ztotwgt
417	WRITE(numout,*) ' ==================================='
418	ENDIF
419
420	ENDIF
421
422	!--------------------------------------------------------------------
423	! Allocate and initialize the increment arrays
424	!--------------------------------------------------------------------
425
426	ALLOCATE( t_bkginc(jpi,jpj,jpk) )
427	ALLOCATE( s_bkginc(jpi,jpj,jpk) )
428	ALLOCATE( u_bkginc(jpi,jpj,jpk) )
429	ALLOCATE( v_bkginc(jpi,jpj,jpk) )
430	ALLOCATE( ssh_bkginc(jpi,jpj) )
431	ALLOCATE( seaice_bkginc(jpi,jpj))
432	#if defined key_asminc
433	ALLOCATE( ssh_iau(jpi,jpj) )
434	#endif
435	t_bkginc(:,:,:) = 0.0
436	s_bkginc(:,:,:) = 0.0
437	u_bkginc(:,:,:) = 0.0
438	v_bkginc(:,:,:) = 0.0
439	ssh_bkginc(:,:) = 0.0
440	seaice_bkginc(:,:) = 0.0
441	#if defined key_asminc
442	ssh_iau(:,:) = 0.0
443	#endif
444	IF ( ( ln_trainc ).OR.( ln_dyninc ).OR.( ln_sshinc ).OR.( ln_seaiceinc ) ) THEN
445
446	!--------------------------------------------------------------------
447	! Read the increments from file
448	!--------------------------------------------------------------------
449
450	CALL iom_open( c_asminc, inum )
451
452	CALL iom_get( inum, 'time', zdate_inc )
453
454	CALL iom_get( inum, 'z_inc_dateb', z_inc_dateb )
455	CALL iom_get( inum, 'z_inc_datef', z_inc_datef )
456	z_inc_dateb = zdate_inc
457	z_inc_datef = zdate_inc
458
459	IF(lwp) THEN
460	WRITE(numout,*)
461	WRITE(numout,*) 'asm_inc_init : Assimilation increments valid ', &
462	& ' between dates ', NINT( z_inc_dateb ),' and ', &
463	& NINT( z_inc_datef )
464	WRITE(numout,*) '~~~~~~~~~~~~'
465	ENDIF
466
467	IF ( ( NINT( z_inc_dateb ) < ndastp ) &
468	& .OR.( NINT( z_inc_datef ) > iitend_date ) ) &
469	& CALL ctl_warn( ' Validity time of assimilation increments is ', &
470	& ' outside the assimilation interval' )
471
472	IF ( ( ln_asmdin ).AND.( NINT( zdate_inc ) /= iitdin_date ) ) &
473	& CALL ctl_warn( ' Validity time of assimilation increments does ', &
474	& ' not agree with Direct Initialization time' )
475
476	IF ( ln_trainc ) THEN
477
478	IF (ln_sco) THEN
479
480	ALLOCATE(z_mld(jpi,jpj))
481	SELECT CASE(mld_choice)
482	CASE(1)
483	z_mld = hmld
484	CASE(2)
485	z_mld = hmlp
486	CASE(3)
487	#if defined key_karaml
488	z_mld = hmld_kara
489	#endif
490	CALL ctl_stop("Kara mixed layer not defined in current version of NEMO") ! JW: Safty feature, should be removed
491	! once the kara mixed layer is availible
492	CASE(4)
493	z_mld = hmld_tref
494	END SELECT
495
496	ALLOCATE( t_bkginc_2d(jpi,jpj) )
497	CALL iom_get( inum, jpdom_autoglo, 'bckinsurft', t_bkginc_2d, 1)
498	#if defined key_bdy
499	DO jk = 1,jpkm1
500	WHERE( z_mld(:,:) > fsdepw(:,:,jk) )
501	t_bkginc(:,:,jk) = t_bkginc_2d(:,:) * bdytmask(:,:)
502	ELSEWHERE
503	t_bkginc(:,:,jk) = 0.
504	ENDWHERE
505	ENDDO
506	#else
507	t_bkginc(:,:,:) = 0.
508	#endif
509	s_bkginc(:,:,:) = 0.
510
511	!DEALLOCATE temporary arrays
512	DEALLOCATE(z_mld, t_bkginc_2d)
513
514	ELSE
515
516	CALL iom_get( inum, jpdom_autoglo, 'bckint', t_bkginc, 1 )
517	CALL iom_get( inum, jpdom_autoglo, 'bckins', s_bkginc, 1 )
518	! Apply the masks
519	t_bkginc(:,:,:) = t_bkginc(:,:,:) * tmask(:,:,:)
520	s_bkginc(:,:,:) = s_bkginc(:,:,:) * tmask(:,:,:)
521	! Set missing increments to 0.0 rather than 1e+20
522	! to allow for differences in masks
523	WHERE( ABS( t_bkginc(:,:,:) ) > 1.0e+10 ) t_bkginc(:,:,:) = 0.0
524	WHERE( ABS( s_bkginc(:,:,:) ) > 1.0e+10 ) s_bkginc(:,:,:) = 0.0
525
526	ENDIF
527
528	ENDIF
529
530	IF ( ln_dyninc ) THEN
531	CALL iom_get( inum, jpdom_autoglo, 'bckinu', u_bkginc, 1 )
532	CALL iom_get( inum, jpdom_autoglo, 'bckinv', v_bkginc, 1 )
533	! Apply the masks
534	u_bkginc(:,:,:) = u_bkginc(:,:,:) * umask(:,:,:)
535	v_bkginc(:,:,:) = v_bkginc(:,:,:) * vmask(:,:,:)
536	! Set missing increments to 0.0 rather than 1e+20
537	! to allow for differences in masks
538	WHERE( ABS( u_bkginc(:,:,:) ) > 1.0e+10 ) u_bkginc(:,:,:) = 0.0
539	WHERE( ABS( v_bkginc(:,:,:) ) > 1.0e+10 ) v_bkginc(:,:,:) = 0.0
540	ENDIF
541
542	IF ( ln_sshinc ) THEN
543	CALL iom_get( inum, jpdom_autoglo, 'bckineta', ssh_bkginc, 1 )
544	! Apply the masks
545	ssh_bkginc(:,:) = ssh_bkginc(:,:) * tmask(:,:,1)
546	! Set missing increments to 0.0 rather than 1e+20
547	! to allow for differences in masks
548	WHERE( ABS( ssh_bkginc(:,:) ) > 1.0e+10 ) ssh_bkginc(:,:) = 0.0
549	ENDIF
550
551	IF ( ln_seaiceinc ) THEN
552	CALL iom_get( inum, jpdom_autoglo, 'bckinseaice', seaice_bkginc, 1 )
553	! Apply the masks
554	seaice_bkginc(:,:) = seaice_bkginc(:,:) * tmask(:,:,1)
555	! Set missing increments to 0.0 rather than 1e+20
556	! to allow for differences in masks
557	WHERE( ABS( seaice_bkginc(:,:) ) > 1.0e+10 ) seaice_bkginc(:,:) = 0.0
558	ENDIF
559
560	CALL iom_close( inum )
561
562	ENDIF
563
564	!-----------------------------------------------------------------------
565	! Apply divergence damping filter
566	!-----------------------------------------------------------------------
567
568	IF ( ln_dyninc .AND. nn_divdmp > 0 ) THEN
569
570	CALL wrk_alloc(jpi,jpj,hdiv)
571
572	DO jt = 1, nn_divdmp
573
574	DO jk = 1, jpkm1
575
576	hdiv(:,:) = 0._wp
577
578	DO jj = 2, jpjm1
579	DO ji = fs_2, fs_jpim1 ! vector opt.
580	hdiv(ji,jj) = &
581	( e2u(ji ,jj ) * fse3u(ji ,jj ,jk) * u_bkginc(ji ,jj ,jk) &
582	- e2u(ji-1,jj ) * fse3u(ji-1,jj ,jk) * u_bkginc(ji-1,jj ,jk) &
583	+ e1v(ji ,jj ) * fse3v(ji ,jj ,jk) * v_bkginc(ji ,jj ,jk) &
584	- e1v(ji ,jj-1) * fse3v(ji ,jj-1,jk) * v_bkginc(ji ,jj-1,jk) ) &
585	/ ( e1t(ji,jj) * e2t(ji,jj) * fse3t(ji,jj,jk) )
586	END DO
587	END DO
588
589	CALL lbc_lnk( hdiv, 'T', 1. ) ! lateral boundary cond. (no sign change)
590
591	DO jj = 2, jpjm1
592	DO ji = fs_2, fs_jpim1 ! vector opt.
593	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) &
594	- e1t(ji ,jj)e2t(ji ,jj) hdiv(ji ,jj) ) &
595	/ e1u(ji,jj) * umask(ji,jj,jk)
596	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) &
597	- e1t(ji,jj )e2t(ji,jj ) hdiv(ji,jj ) ) &
598	/ e2v(ji,jj) * vmask(ji,jj,jk)
599	END DO
600	END DO
601
602	END DO
603
604	END DO
605
606	CALL wrk_dealloc(jpi,jpj,hdiv)
607
608	ENDIF
609
610
611
612	!-----------------------------------------------------------------------
613	! Allocate and initialize the background state arrays
614	!-----------------------------------------------------------------------
615
616	IF ( ln_asmdin ) THEN
617
618	ALLOCATE( t_bkg(jpi,jpj,jpk) )
619	ALLOCATE( s_bkg(jpi,jpj,jpk) )
620	ALLOCATE( u_bkg(jpi,jpj,jpk) )
621	ALLOCATE( v_bkg(jpi,jpj,jpk) )
622	ALLOCATE( ssh_bkg(jpi,jpj) )
623
624	t_bkg(:,:,:) = 0.0
625	s_bkg(:,:,:) = 0.0
626	u_bkg(:,:,:) = 0.0
627	v_bkg(:,:,:) = 0.0
628	ssh_bkg(:,:) = 0.0
629
630	!--------------------------------------------------------------------
631	! Read from file the background state at analysis time
632	!--------------------------------------------------------------------
633
634	CALL iom_open( c_asmdin, inum )
635
636	CALL iom_get( inum, 'rdastp', zdate_bkg )
637
638	IF(lwp) THEN
639	WRITE(numout,*)
640	WRITE(numout,*) 'asm_inc_init : Assimilation background state valid at : ', &
641	& NINT( zdate_bkg )
642	WRITE(numout,*) '~~~~~~~~~~~~'
643	ENDIF
644
645	IF ( NINT( zdate_bkg ) /= iitdin_date ) &
646	& CALL ctl_warn( ' Validity time of assimilation background state does', &
647	& ' not agree with Direct Initialization time' )
648
649	IF ( ln_trainc ) THEN
650	CALL iom_get( inum, jpdom_autoglo, 'tn', t_bkg )
651	CALL iom_get( inum, jpdom_autoglo, 'sn', s_bkg )
652	t_bkg(:,:,:) = t_bkg(:,:,:) * tmask(:,:,:)
653	s_bkg(:,:,:) = s_bkg(:,:,:) * tmask(:,:,:)
654	ENDIF
655
656	IF ( ln_dyninc ) THEN
657	CALL iom_get( inum, jpdom_autoglo, 'un', u_bkg )
658	CALL iom_get( inum, jpdom_autoglo, 'vn', v_bkg )
659	u_bkg(:,:,:) = u_bkg(:,:,:) * umask(:,:,:)
660	v_bkg(:,:,:) = v_bkg(:,:,:) * vmask(:,:,:)
661	ENDIF
662
663	IF ( ln_sshinc ) THEN
664	CALL iom_get( inum, jpdom_autoglo, 'sshn', ssh_bkg )
665	ssh_bkg(:,:) = ssh_bkg(:,:) * tmask(:,:,1)
666	ENDIF
667
668	CALL iom_close( inum )
669
670	ENDIF
671	!
672	END SUBROUTINE asm_inc_init
673
674
675	SUBROUTINE calc_date( kit000, kt, kdate0, kdate )
676	!!----------------------------------------------------------------------
677	!! * ROUTINE calc_date *
678	!!
679	!! ** Purpose : Compute the calendar date YYYYMMDD at a given time step.
680	!!
681	!! ** Method : Compute the calendar date YYYYMMDD at a given time step.
682	!!
683	!! ** Action :
684	!!----------------------------------------------------------------------
685	INTEGER, INTENT(IN) :: kit000 ! Initial time step
686	INTEGER, INTENT(IN) :: kt ! Current time step referenced to kit000
687	INTEGER, INTENT(IN) :: kdate0 ! Initial date
688	INTEGER, INTENT(OUT) :: kdate ! Current date reference to kdate0
689	!
690	INTEGER :: iyea0 ! Initial year
691	INTEGER :: imon0 ! Initial month
692	INTEGER :: iday0 ! Initial day
693	INTEGER :: iyea ! Current year
694	INTEGER :: imon ! Current month
695	INTEGER :: iday ! Current day
696	INTEGER :: idaystp ! Number of days between initial and current date
697	INTEGER :: idaycnt ! Day counter
698
699	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
700
701	!-----------------------------------------------------------------------
702	! Compute the calendar date YYYYMMDD
703	!-----------------------------------------------------------------------
704
705	! Initial date
706	iyea0 = kdate0 / 10000
707	imon0 = ( kdate0 - ( iyea0 * 10000 ) ) / 100
708	iday0 = kdate0 - ( iyea0 * 10000 ) - ( imon0 * 100 )
709
710	! Check that kt >= kit000 - 1
711	IF ( kt < kit000 - 1 ) CALL ctl_stop( ' kt must be >= kit000 - 1')
712
713	! If kt = kit000 - 1 then set the date to the restart date
714	IF ( kt == kit000 - 1 ) THEN
715
716	kdate = ndastp
717	RETURN
718
719	ENDIF
720
721	! Compute the number of days from the initial date
722	idaystp = INT( REAL( kt - kit000 ) * rdt / 86400. )
723
724	iday = iday0
725	imon = imon0
726	iyea = iyea0
727	idaycnt = 0
728
729	CALL calc_month_len( iyea, imonth_len )
730
731	DO WHILE ( idaycnt < idaystp )
732	iday = iday + 1
733	IF ( iday > imonth_len(imon) ) THEN
734	iday = 1
735	imon = imon + 1
736	ENDIF
737	IF ( imon > 12 ) THEN
738	imon = 1
739	iyea = iyea + 1
740	CALL calc_month_len( iyea, imonth_len ) ! update month lengths
741	ENDIF
742	idaycnt = idaycnt + 1
743	END DO
744	!
745	kdate = iyea * 10000 + imon * 100 + iday
746	!
747	END SUBROUTINE
748
749
750	SUBROUTINE calc_month_len( iyear, imonth_len )
751	!!----------------------------------------------------------------------
752	!! * ROUTINE calc_month_len *
753	!!
754	!! ** Purpose : Compute the number of days in a months given a year.
755	!!
756	!! ** Method :
757	!!----------------------------------------------------------------------
758	INTEGER, DIMENSION(12) :: imonth_len !: length in days of the months of the current year
759	INTEGER :: iyear !: year
760	!!----------------------------------------------------------------------
761	!
762	! length of the month of the current year (from nleapy, read in namelist)
763	IF ( nleapy < 2 ) THEN
764	imonth_len(:) = (/ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 /)
765	IF ( nleapy == 1 ) THEN ! we are using calendar with leap years
766	IF ( MOD(iyear, 4) == 0 .AND. ( MOD(iyear, 400) == 0 .OR. MOD(iyear, 100) /= 0 ) ) THEN
767	imonth_len(2) = 29
768	ENDIF
769	ENDIF
770	ELSE
771	imonth_len(:) = nleapy ! all months with nleapy days per year
772	ENDIF
773	!
774	END SUBROUTINE
775
776
777	SUBROUTINE tra_asm_inc( kt )
778	!!----------------------------------------------------------------------
779	!! * ROUTINE tra_asm_inc *
780	!!
781	!! ** Purpose : Apply the tracer (T and S) assimilation increments
782	!!
783	!! ** Method : Direct initialization or Incremental Analysis Updating
784	!!
785	!! ** Action :
786	!!----------------------------------------------------------------------
787	INTEGER, INTENT(IN) :: kt ! Current time step
788	!
789	INTEGER :: ji,jj,jk
790	INTEGER :: it
791	REAL(wp) :: zincwgt ! IAU weight for current time step
792	REAL (wp), DIMENSION(jpi,jpj,jpk) :: fzptnz ! 3d freezing point values
793	!!----------------------------------------------------------------------
794
795	! freezing point calculation taken from oc_fz_pt (but calculated for all depths)
796	! used to prevent the applied increments taking the temperature below the local freezing point
797
798	! Note: For NEMO/CICE this will be identical to nTf (for the surface), but defined at the now point.
799
800	DO jk=1, jpkm1
801	fzptnz (:,:,jk) = tfreez(tsn(:,:,jk,jp_sal )) - 7.53e-4_wp * fsdepw(:,:,jk)
802	ENDDO
803
804	IF ( ln_asmiau ) THEN
805
806	!--------------------------------------------------------------------
807	! Incremental Analysis Updating
808	!--------------------------------------------------------------------
809
810	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
811
812	it = kt - nit000 + 1
813	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
814
815	IF(lwp) THEN
816	WRITE(numout,*)
817	WRITE(numout,*) 'tra_asm_inc : Tracer IAU at time step = ', &
818	& kt,' with IAU weight = ', wgtiau(it)
819	WRITE(numout,*) '~~~~~~~~~~~~'
820	ENDIF
821
822	! Update the tracer tendencies
823	DO jk = 1, jpkm1
824	IF (ln_temnofreeze) THEN
825	! Do not apply negative increments if the temperature will fall below freezing
826	WHERE(t_bkginc(:,:,jk) > 0.0_wp .OR. &
827	& tsn(:,:,jk,jp_tem) + tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * wgtiau(it) > fzptnz(:,:,jk) )
828	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
829	END WHERE
830	ELSE
831	tsa(:,:,jk,jp_tem) = tsa(:,:,jk,jp_tem) + t_bkginc(:,:,jk) * zincwgt
832	ENDIF
833	IF (ln_salfix) THEN
834	! Do not apply negative increments if the salinity will fall below a specified
835	! minimum value salfixmin
836	WHERE(s_bkginc(:,:,jk) > 0.0_wp .OR. &
837	& tsn(:,:,jk,jp_sal) + tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * wgtiau(it) > salfixmin )
838	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
839	END WHERE
840	ELSE
841	tsa(:,:,jk,jp_sal) = tsa(:,:,jk,jp_sal) + s_bkginc(:,:,jk) * zincwgt
842	ENDIF
843	END DO
844
845	ENDIF
846
847	IF ( kt == nitiaufin_r + 1 ) THEN ! For bias crcn to work
848	DEALLOCATE( t_bkginc )
849	DEALLOCATE( s_bkginc )
850	ENDIF
851
852
853	ELSEIF ( ln_asmdin ) THEN
854
855	!--------------------------------------------------------------------
856	! Direct Initialization
857	!--------------------------------------------------------------------
858
859	IF ( kt == nitdin_r ) THEN
860
861	neuler = 0 ! Force Euler forward step
862
863	! Initialize the now fields with the background + increment
864	IF (ln_temnofreeze) THEN
865	! Do not apply negative increments if the temperature will fall below freezing
866	WHERE(t_bkginc(:,:,:) > 0.0_wp .OR. &
867	& tsn(:,:,:,jp_tem) + t_bkginc(:,:,:) > fzptnz(:,:,:) )
868	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
869	END WHERE
870	ELSE
871	tsn(:,:,:,jp_tem) = t_bkg(:,:,:) + t_bkginc(:,:,:)
872	ENDIF
873	IF (ln_salfix) THEN
874	! Do not apply negative increments if the salinity will fall below a specified
875	! minimum value salfixmin
876	WHERE(s_bkginc(:,:,:) > 0.0_wp .OR. &
877	& tsn(:,:,:,jp_sal) + s_bkginc(:,:,:) > salfixmin )
878	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
879	END WHERE
880	ELSE
881	tsn(:,:,:,jp_sal) = s_bkg(:,:,:) + s_bkginc(:,:,:)
882	ENDIF
883
884	tsb(:,:,:,:) = tsn(:,:,:,:) ! Update before fields
885
886	CALL eos( tsb, rhd, rhop ) ! Before potential and in situ densities
887
888	IF( ln_zps .AND. .NOT. lk_c1d ) &
889	& CALL zps_hde( nit000, jpts, tsb, & ! Partial steps: before horizontal derivative
890	& gtsu, gtsv, rhd, & ! of T, S, rd at the bottom ocean level
891	& gru , grv )
892
893	#if defined key_zdfkpp
894	CALL eos( tsn, rhd ) ! Compute rhd
895	#endif
896
897	DEALLOCATE( t_bkginc )
898	DEALLOCATE( s_bkginc )
899	DEALLOCATE( t_bkg )
900	DEALLOCATE( s_bkg )
901	ENDIF
902	!
903	ENDIF
904	! Perhaps the following call should be in step
905	IF ( ln_seaiceinc ) CALL seaice_asm_inc ( kt ) ! apply sea ice concentration increment
906	!
907	END SUBROUTINE tra_asm_inc
908
909
910	SUBROUTINE dyn_asm_inc( kt )
911	!!----------------------------------------------------------------------
912	!! * ROUTINE dyn_asm_inc *
913	!!
914	!! ** Purpose : Apply the dynamics (u and v) assimilation increments.
915	!!
916	!! ** Method : Direct initialization or Incremental Analysis Updating.
917	!!
918	!! ** Action :
919	!!----------------------------------------------------------------------
920	INTEGER, INTENT(IN) :: kt ! Current time step
921	!
922	INTEGER :: jk
923	INTEGER :: it
924	REAL(wp) :: zincwgt ! IAU weight for current time step
925	!!----------------------------------------------------------------------
926
927	IF ( ln_asmiau ) THEN
928
929	!--------------------------------------------------------------------
930	! Incremental Analysis Updating
931	!--------------------------------------------------------------------
932
933	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
934
935	it = kt - nit000 + 1
936	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
937
938	IF(lwp) THEN
939	WRITE(numout,*)
940	WRITE(numout,*) 'dyn_asm_inc : Dynamics IAU at time step = ', &
941	& kt,' with IAU weight = ', wgtiau(it)
942	WRITE(numout,*) '~~~~~~~~~~~~'
943	ENDIF
944
945	! Update the dynamic tendencies
946	DO jk = 1, jpkm1
947	ua(:,:,jk) = ua(:,:,jk) + u_bkginc(:,:,jk) * zincwgt
948	va(:,:,jk) = va(:,:,jk) + v_bkginc(:,:,jk) * zincwgt
949	END DO
950
951	IF ( kt == nitiaufin_r ) THEN
952	DEALLOCATE( u_bkginc )
953	DEALLOCATE( v_bkginc )
954	ENDIF
955
956	ENDIF
957
958	ELSEIF ( ln_asmdin ) THEN
959
960	!--------------------------------------------------------------------
961	! Direct Initialization
962	!--------------------------------------------------------------------
963
964	IF ( kt == nitdin_r ) THEN
965
966	neuler = 0 ! Force Euler forward step
967
968	! Initialize the now fields with the background + increment
969	un(:,:,:) = u_bkg(:,:,:) + u_bkginc(:,:,:)
970	vn(:,:,:) = v_bkg(:,:,:) + v_bkginc(:,:,:)
971
972	ub(:,:,:) = un(:,:,:) ! Update before fields
973	vb(:,:,:) = vn(:,:,:)
974
975	DEALLOCATE( u_bkg )
976	DEALLOCATE( v_bkg )
977	DEALLOCATE( u_bkginc )
978	DEALLOCATE( v_bkginc )
979	ENDIF
980	!
981	ENDIF
982	!
983	END SUBROUTINE dyn_asm_inc
984
985
986	SUBROUTINE ssh_asm_inc( kt )
987	!!----------------------------------------------------------------------
988	!! * ROUTINE ssh_asm_inc *
989	!!
990	!! ** Purpose : Apply the sea surface height assimilation increment.
991	!!
992	!! ** Method : Direct initialization or Incremental Analysis Updating.
993	!!
994	!! ** Action :
995	!!----------------------------------------------------------------------
996	INTEGER, INTENT(IN) :: kt ! Current time step
997	!
998	INTEGER :: it
999	INTEGER :: jk
1000	REAL(wp) :: zincwgt ! IAU weight for current time step
1001	!!----------------------------------------------------------------------
1002
1003	IF ( ln_asmiau ) THEN
1004
1005	!--------------------------------------------------------------------
1006	! Incremental Analysis Updating
1007	!--------------------------------------------------------------------
1008
1009	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
1010
1011	it = kt - nit000 + 1
1012	zincwgt = wgtiau(it) / rdt ! IAU weight for the current time step
1013
1014	IF(lwp) THEN
1015	WRITE(numout,*)
1016	WRITE(numout,*) 'ssh_asm_inc : SSH IAU at time step = ', &
1017	& kt,' with IAU weight = ', wgtiau(it)
1018	WRITE(numout,*) '~~~~~~~~~~~~'
1019	ENDIF
1020
1021	! Save the tendency associated with the IAU weighted SSH increment
1022	! (applied in dynspg.*)
1023	#if defined key_asminc
1024	ssh_iau(:,:) = ssh_bkginc(:,:) * zincwgt
1025	#endif
1026	IF ( kt == nitiaufin_r ) THEN
1027	DEALLOCATE( ssh_bkginc )
1028	ENDIF
1029
1030	ENDIF
1031
1032	ELSEIF ( ln_asmdin ) THEN
1033
1034	!--------------------------------------------------------------------
1035	! Direct Initialization
1036	!--------------------------------------------------------------------
1037
1038	IF ( kt == nitdin_r ) THEN
1039
1040	neuler = 0 ! Force Euler forward step
1041
1042	! Initialize the now fields the background + increment
1043	sshn(:,:) = ssh_bkg(:,:) + ssh_bkginc(:,:)
1044
1045	! Update before fields
1046	sshb(:,:) = sshn(:,:)
1047
1048	DEALLOCATE( ssh_bkg )
1049	DEALLOCATE( ssh_bkginc )
1050
1051	ENDIF
1052	!
1053	ENDIF
1054	!
1055	END SUBROUTINE ssh_asm_inc
1056
1057	SUBROUTINE seaice_asm_inc( kt, kindic )
1058	!!----------------------------------------------------------------------
1059	!! * ROUTINE seaice_asm_inc *
1060	!!
1061	!! ** Purpose : Apply the sea ice assimilation increment.
1062	!!
1063	!! ** Method : Direct initialization or Incremental Analysis Updating.
1064	!!
1065	!! ** Action :
1066	!!
1067	!! History :
1068	!! ! 07-2011 (D. Lea) Initial version based on ssh_asm_inc
1069	!!----------------------------------------------------------------------
1070
1071	IMPLICIT NONE
1072
1073	!! * Arguments
1074	INTEGER, INTENT(IN) :: kt ! Current time step
1075	INTEGER, OPTIONAL, INTENT(IN) :: kindic ! flag for disabling the deallocation
1076
1077	!! * Local declarations
1078	INTEGER :: it
1079	REAL(wp) :: zincwgt ! IAU weight for current time step
1080
1081	#if defined key_lim3 \|\| defined key_lim2
1082	REAL(wp), DIMENSION(jpi,jpj) :: zofrld, zohicif, zseaicendg, zhicifinc ! LIM
1083	REAL(wp) :: zhicifmin=0.5_wp ! ice minimum depth in metres
1084
1085	#endif
1086
1087
1088	IF ( ln_asmiau ) THEN
1089
1090	!--------------------------------------------------------------------
1091	! Incremental Analysis Updating
1092	!--------------------------------------------------------------------
1093
1094	IF ( ( kt >= nitiaustr_r ).AND.( kt <= nitiaufin_r ) ) THEN
1095
1096	it = kt - nit000 + 1
1097	zincwgt = wgtiau(it) ! IAU weight for the current time step
1098	! note this is not a tendency so should not be divided by rdt (as with the tracer and other increments)
1099
1100	IF(lwp) THEN
1101	WRITE(numout,*)
1102	WRITE(numout,*) 'seaice_asm_inc : sea ice conc IAU at time step = ', &
1103	& kt,' with IAU weight = ', wgtiau(it)
1104	WRITE(numout,*) '~~~~~~~~~~~~'
1105	ENDIF
1106
1107	#if defined key_lim3 \|\| defined key_lim2
1108
1109	zofrld(:,:)=frld(:,:)
1110	zohicif(:,:)=hicif(:,:)
1111
1112	frld = MIN( MAX( frld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1113	pfrld = MIN( MAX( pfrld(:,:) - seaice_bkginc(:,:) * zincwgt, 0.0_wp), 1.0_wp)
1114	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1115
1116	zseaicendg(:,:)=zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1117
1118	! Nudge sea ice depth to bring it up to a required minimum depth
1119
1120	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1121	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1122	ELSEWHERE
1123	zhicifinc(:,:) = 0.0_wp
1124	END WHERE
1125
1126	! nudge ice depth
1127	hicif(:,:)=hicif(:,:) + zhicifinc(:,:)
1128	phicif(:,:)=phicif(:,:) + zhicifinc(:,:)
1129
1130	! seaice salinity balancing (to add)
1131
1132	#endif
1133
1134	#if defined key_cice
1135
1136	! Pass ice increment tendency into CICE
1137	ndaice_da(:,:) = seaice_bkginc(:,:) * zincwgt / rdt
1138
1139	#endif
1140
1141	IF ( kt == nitiaufin_r ) THEN
1142	DEALLOCATE( seaice_bkginc )
1143	ENDIF
1144
1145	ELSE
1146
1147	#if defined key_cice
1148
1149	! Zero ice increment tendency into CICE
1150	ndaice_da(:,:) = 0.0_wp
1151
1152	#endif
1153
1154	ENDIF
1155
1156	ELSEIF ( ln_asmdin ) THEN
1157
1158	!--------------------------------------------------------------------
1159	! Direct Initialization
1160	!--------------------------------------------------------------------
1161
1162	IF ( kt == nitdin_r ) THEN
1163
1164	neuler = 0 ! Force Euler forward step
1165
1166	#if defined key_lim3 \|\| defined key_lim2
1167
1168	zofrld(:,:)=frld(:,:)
1169	zohicif(:,:)=hicif(:,:)
1170
1171	! Initialize the now fields the background + increment
1172
1173	frld(:,:) = MIN( MAX( frld(:,:) - seaice_bkginc(:,:), 0.0_wp), 1.0_wp)
1174	pfrld(:,:) = frld(:,:)
1175	fr_i(:,:) = 1.0_wp - frld(:,:) ! adjust ice fraction
1176
1177	zseaicendg(:,:)=zofrld(:,:) - frld(:,:) ! find out actual sea ice nudge applied
1178
1179	! Nudge sea ice depth to bring it up to a required minimum depth
1180
1181	WHERE( zseaicendg(:,:) > 0.0_wp .AND. hicif(:,:) < zhicifmin )
1182	zhicifinc(:,:) = (zhicifmin - hicif(:,:)) * zincwgt
1183	ELSEWHERE
1184	zhicifinc(:,:) = 0.0_wp
1185	END WHERE
1186
1187	! nudge ice depth
1188	hicif(:,:)=hicif(:,:) + zhicifinc(:,:)
1189	phicif(:,:)=phicif(:,:)
1190
1191	! seaice salinity balancing (to add)
1192
1193	#endif
1194
1195	#if defined key_cice
1196
1197	! Pass ice increment tendency into CICE - is this correct?
1198	ndaice_da(:,:) = seaice_bkginc(:,:) / rdt
1199
1200	#endif
1201	IF ( .NOT. PRESENT(kindic) ) THEN
1202	DEALLOCATE( seaice_bkginc )
1203	END IF
1204
1205	ELSE
1206
1207	#if defined key_cice
1208
1209	! Zero ice increment tendency into CICE
1210	ndaice_da(:,:) = 0.0_wp
1211
1212	#endif
1213
1214	ENDIF
1215
1216	!#if defined key_lim3 \|\| defined key_lim2 \|\| defined key_cice
1217	!
1218	! IF (ln_seaicebal ) THEN
1219	! !! balancing salinity increments
1220	! !! simple case from limflx.F90 (doesn't include a mass flux)
1221	! !! assumption is that as ice concentration is reduced or increased
1222	! !! the snow and ice depths remain constant
1223	! !! note that snow is being created where ice concentration is being increased
1224	! !! - could be more sophisticated and
1225	! !! not do this (but would need to alter h_snow)
1226	!
1227	! usave(:,:,:)=sb(:,:,:) ! use array as a temporary store
1228	!
1229	! DO jj = 1, jpj
1230	! DO ji = 1, jpi
1231	! ! calculate change in ice and snow mass per unit area
1232	! ! positive values imply adding salt to the ocean (results from ice formation)
1233	! ! fwf : ice formation and melting
1234	!
1235	! zfons = ( -nfresh_da(ji,jj)soce + nfsalt_da(ji,jj) )rdt
1236	!
1237	! ! change salinity down to mixed layer depth
1238	! mld=hmld_kara(ji,jj)
1239	!
1240	! ! prevent small mld
1241	! ! less than 10m can cause salinity instability
1242	! IF (mld < 10) mld=10
1243	!
1244	! ! set to bottom of a level
1245	! DO jk = jpk-1, 2, -1
1246	! IF ((mld > gdepw(ji,jj,jk)) .and. (mld < gdepw(ji,jj,jk+1))) THEN
1247	! mld=gdepw(ji,jj,jk+1)
1248	! jkmax=jk
1249	! ENDIF
1250	! ENDDO
1251	!
1252	! ! avoid applying salinity balancing in shallow water or on land
1253	! !
1254	!
1255	! ! dsal_ocn (psu kg m^-2) / (kg m^-3 * m)
1256	!
1257	! dsal_ocn=0.0_wp
1258	! sal_thresh=5.0_wp ! minimum salinity threshold for salinity balancing
1259	!
1260	! if (tmask(ji,jj,1) > 0 .AND. tmask(ji,jj,jkmax) > 0 ) &
1261	! dsal_ocn = zfons / (rhop(ji,jj,1) * mld)
1262	!
1263	! ! put increments in for levels in the mixed layer
1264	! ! but prevent salinity below a threshold value
1265	!
1266	! DO jk = 1, jkmax
1267	!
1268	! IF (dsal_ocn > 0.0_wp .or. sb(ji,jj,jk)+dsal_ocn > sal_thresh) THEN
1269	! sb(ji,jj,jk) = sb(ji,jj,jk) + dsal_ocn
1270	! sn(ji,jj,jk) = sn(ji,jj,jk) + dsal_ocn
1271	! ENDIF
1272	!
1273	! ENDDO
1274	!
1275	! ! ! salt exchanges at the ice/ocean interface
1276	! ! zpmess = zfons / rdt_ice ! rdt_ice is ice timestep
1277	! !
1278	! !! Adjust fsalt. A +ve fsalt means adding salt to ocean
1279	! !! fsalt(ji,jj) = fsalt(ji,jj) + zpmess ! adjust fsalt
1280	! !!
1281	! !! emps(ji,jj) = emps(ji,jj) + zpmess ! or adjust emps (see icestp1d)
1282	! !! ! E-P (kg m-2 s-2)
1283	! ! emp(ji,jj) = emp(ji,jj) + zpmess ! E-P (kg m-2 s-2)
1284	! ENDDO !ji
1285	! ENDDO !jj!
1286	!
1287	! ENDIF !ln_seaicebal
1288	!
1289	!#endif
1290
1291
1292	ENDIF
1293
1294	END SUBROUTINE seaice_asm_inc
1295	!!======================================================================
1296	END MODULE asminc

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source: branches/UKMO/CO5_package_branch/NEMOGCM/NEMO/OPA_SRC/ASM/asminc.F90 @ 7367

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