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bias.F90 @ 15749

Last change on this file since 15749 was 15749, checked in by jwhile, 2 years ago
Fix for pcbias boundary.
File size: 50.1 KB

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1	MODULE bias
2	!! Is used by OPA and STEP
3	!!======================================================================
4	!! * Module bias *
5	!! Code to estimate and apply bias correction.
6	!! The bias is in T/S and Pressure. It follows the generalized
7	!! bias algorithm presented in Balmaseda et al 2007.
8	!!
9	!! It can be read from a file offline, estimated online from relaxation
10	!! terms or from assimilation increments (this latter estimtd in inner loop)
11	!!
12	!! The parameters for the time evolution of the bias can be different
13	!! from the relaxation terms and for the assim increments. Only the
14	!! parameter for the relaxtion terms are considered here.
15	!!
16	!! The offline bias term can contain the seasonal cycle.
17	!!
18	!! The time evolution of the bias for relaxtion is estimated as followed
19	!! bias_rlx(t+1)=t_rlx_membias_rlx(t)+t_rlx_upd(t/s)trdmp.
20	!!
21	!! The total bias in T/S is partion between the correction to T/S only
22	!! (fb_t) and the correction applied to the pressure gradient (fb_p).
23	!! We impose that (fb_p=1.-fb_t). These factors can be different for the
24	!! different terms(fb_t_rxl,fb_t_asm,fb_t_ofl)
25	!!
26	!! (t/s)bias = fb_t_ofl * (t/s)bias_ofl +
27	!! fb_t_rlx * (t/s)bias_rlx +
28	!! fb_t_asm * (t/s)bias_asm
29	!! (t/s)bias_p =fb_p_ofl * (t/s)bias_ofl+
30	!! fb_p_rlx * (t/s)bias_rlx_p +
31	!! fb_p_asm * (t/s)bias_asm_p
32	!! (t/s)bias is applied directely to correct T and S
33	!! (t/s)bias_p is used to compute rhd_pc and gru/v_pc
34	!!
35	!! Note: the above is an adhoc /simple way of making the partition
36	!! between bias in pressure and bias in T/S. It would be better
37	!! if the partition is done at the time of estimating the time
38	!! evolution of the bias. That would mean doubling the number of
39	!! 3D arrays.
40	!!
41	!! New addtion: (not in Balmaseda et al 2007):
42	!! A more physical alternative to the partition of the bias can be
43	!! done in terms of the inertial frequency: when the time scales of
44	!! adjustment are shorter that >1/f (Equator), the bias correction should
45	!! be in the the pressure term. Otherwise, it can act directly in T/S.
46	!! NOTE that the bias correction in the pressure term here (following
47	!! (Bell et al 2007) is just the "opposite" as the semi-prognostic method
48	!! in Greatbatch et al 2004.
49	!! The use of this partition is controlled by ln_inertial=.true.
50	!!
51	!!
52	!! 2009-03 (M.A. Balmaseda ECMWF)
53	!!======================================================================
54
55	!!----------------------------------------------------------------------
56	!! bias_init : Read in the bias namelist and the bias arrays
57	!! tra_bias : Apply the bias fields on T/S directly
58	!! dyn_bias : Compute density correction for dynamic hpg
59	!! bias_opn : open bias files for restart capabilities
60	!! bias_wrt : write bias fies " " "
61	!!----------------------------------------------------------------------
62	!! * Modules used
63	USE par_kind, ONLY: &
64	& wp
65	USE par_oce, ONLY: &
66	& jpi, &
67	& jpj, &
68	& jpk
69	USE dom_oce, ONLY: &
70	& rdt, &
71	& ln_zps, &
72	& gphit
73	USE phycst, ONLY: &
74	& rday, &
75	& rad
76	USE oce, ONLY: &
77	& tsb, tsn, tsa, &
78	& rhop, &
79	& gtsu, gtsv
80	USE dynhpg, ONLY: &
81	& ln_dynhpg_imp
82	USE tradmp
83	USE dtatsd, ONLY: &
84	& ln_tsd_tradmp
85	USE in_out_manager, ONLY: &
86	& lwp, &
87	& numnam_ref, &
88	& numnam_cfg, &
89	& numond, &
90	& numout, &
91	& lrst_oce, &
92	& nit000
93	USE iom
94	USE eosbn2
95	USE zpshde ! partial step: hor. derivative (zps_hde routine)
96	USE biaspar
97	USE fldread ! read input fields
98	USE lbclnk ! lateral boundary conditions (or mpp link)
99	USE asmpar
100	USE asminc
101	USE lib_mpp, ONLY: &
102	& ctl_stop, &
103	& ctl_nam
104
105	IMPLICIT NONE
106
107	!! * Routine accessibility
108	PRIVATE
109	PUBLIC bias_init, & !: Read in the bias namelist and the bias arrays
110	& tra_bias, & !: Estimate/apply bias on traces
111	& dyn_bias, & !: " density correction for pressure gradient.
112	& bias_opn, &
113	& bias_wrt
114
115	!! * Substitutions needed to have the variable fsdept_n
116	# include "domzgr_substitute.h90"
117	!! * Shared variables
118	!! * Private module variables
119	REAL(wp), PRIVATE :: &
120	& bias_time_unit_asm, & !: bias_asm units in s ( per day = 86400 s)
121	& bias_time_unit_rlx, & !: bias_rlx units in s ( 1 second)
122	& bias_time_unit_ofl, & !: bias_ofl units in s ( 1 second)
123	& t_rlx_mem, & !: time param for mem in bias_rlx model
124	& t_rlx_upd, & !: time param for update in bias_rlx model
125	!: (pct of incr for computation of bias)
126	& t_asm_mem, & !: time param for mem in bias_asm model
127	& t_asm_upd, & !: time param for update in bias_asm model
128	!: (pct of incr for computation of bias)
129	& fb_t_rlx, & !: parition of bias in T for rlx bias term
130	& fb_t_asm, & !: parition of bias in T for asm bias term
131	& fb_t_ofl, & !: parition of bias in T for ofl bias term
132	& fb_p_rlx, & !: parition of bias in P for rlx bias term
133	& fb_p_asm, & !: parition of bias in P for asm bias term
134	& fb_p_ofl, & !: parition of bias in P for ofl bias term
135	& fctamp, & !: amplification factor for T if inertial
136	& rn_maxlat_bias, & !: Max lat for latitudinal ramp
137	& rn_minlat_bias, & !: Min lat for latitudinal ramp
138	& zwgt, & !: weight for IPC
139	& ztscale !: decay rate for IPC
140
141	LOGICAL, PRIVATE :: lalloc
142	REAL(wp), PRIVATE, DIMENSION(:,:,:), ALLOCATABLE :: &
143	& tbias_asm, & !: Temperature bias field
144	& sbias_asm, & !: Salinity bias field
145	& tbias_rlx, & !: Temperature bias field
146	& sbias_rlx, & !: Salinity bias field
147	& tbias_asm_out, & !: Output temperature bias field
148	& sbias_asm_out, & !: Output salinity bias field
149	& tbias_rlx_out, & !: Output temperature bias field
150	& sbias_rlx_out, & !: Output salinity bias field
151	& tbias_p_out, & !: Output temperature bias field for P correction
152	& sbias_p_out, & !: Output salinity bias field for P correction
153	& tbias_i_out, & !: Output temperature bias field for incremental P correction
154	& sbias_i_out, & !: Output salinity bias field for incremental P correction
155	& tbias_asm_stscale, & !: Short time scale temperature bias field
156	& sbias_asm_stscale, & !: Short time scale salinity bias field
157	& tbias_asm_stscale_out, & !: Short time scale temperature bias output field
158	& sbias_asm_stscale_out !: Short time scale salinity bias output field
159
160	INTEGER, PRIVATE :: nn_lat_ramp ! choice of latitude dependent ramp
161	! for the pressure correction.
162	! 1:inertial ramp, 2:linear ramp, else:no ramp
163	LOGICAL, PRIVATE :: ln_bsyncro ! syncronous or assincrous bias correction
164	LOGICAL, PRIVATE :: ln_itdecay ! evolve bias correction at every time step.
165	LOGICAL, PRIVATE :: ln_incpc ! incremental pressure correction plus pressure correction
166	LOGICAL, PRIVATE :: ln_incpc_only ! incremental pressure correction only
167
168	REAL(wp), PRIVATE, DIMENSION(:,:), ALLOCATABLE :: fbcoef
169	REAL(wp), PRIVATE, DIMENSION(:,:), ALLOCATABLE :: fbcoef_stscale
170
171	INTEGER, PRIVATE :: &
172	& numbias_asm, & ! netcdf id of bias file from assim
173	& numbias_tot, & ! netcdf id of bias file with total bias
174	& nn_bias_itwrt ! time step for outputting bias pressure corr
175
176	CHARACTER(LEN=128), PRIVATE :: &
177	& cn_bias_asm, & ! name of bias file from assim
178	& cn_bias_tot ! name of bias with total/rlx bias
179
180	! Structure of input T and S bias offline (file informations, fields read)
181	TYPE(FLD), PRIVATE, ALLOCATABLE, DIMENSION(:) :: sf_tbias_ofl
182	TYPE(FLD), PRIVATE, ALLOCATABLE, DIMENSION(:) :: sf_sbias_ofl
183
184	TYPE(FLD_N), PRIVATE ::& ! information about the fields to be read
185	& sn_tbias_ofl, sn_sbias_ofl
186
187	CONTAINS
188
189	SUBROUTINE bias_init
190	!!----------------------------------------------------------------------
191	!! * ROUTINE bias_init *
192	!!
193	!! ** Purpose : Read in the bias namelist and read in the bias fields.
194	!!
195	!! ** Method : Read in the bias namelist and read in the bias fields.
196	!!
197	!! ** Action :
198	!!
199	!! History :
200	!! ! 08-05 (D. Lea) Initial version
201	!! ! 08-10 (M. Martin) Tidy
202	!! ! 09-03 (M. Balmaseda). Generalize to estimate the bias
203	!! from relax and offline bias term.
204	!! Introduce parameters to control the
205	!! model for the bias
206	!! (variables and time evolution)
207	!!----------------------------------------------------------------------
208
209	IMPLICIT NONE
210
211	!! * Local declarations
212
213	CHARACTER(len=100) :: cn_dir ! dir for location ofline bias
214	INTEGER :: ierror
215	INTEGER :: ios ! Local integer output status for namelist read
216	REAL(wp) :: eft_rlx, & ! efolding time (bias memory) in days
217	& eft_asm, & ! " "
218	& log2, &
219	& lenscl_bias, & ! lengthscale pressure bias decay between minlat and maxlat.
220	& minlat_bias, & ! used in ipc
221	& maxlat_bias ! used in ipc
222
223	NAMELIST/nambias/ ln_bias, ln_bias_asm, ln_bias_rlx, ln_bias_ofl, &
224	& ln_bias_ts_app, ln_bias_pc_app, &
225	& fb_t_asm, fb_t_rlx, fb_t_ofl, fb_p_asm, fb_p_rlx, fb_p_ofl, &
226	& eft_rlx, t_rlx_upd, eft_asm, t_asm_upd, nn_lat_ramp, &
227	& bias_time_unit_asm, bias_time_unit_rlx, bias_time_unit_ofl, &
228	& cn_bias_tot, cn_bias_asm, cn_dir, sn_tbias_ofl, sn_sbias_ofl, &
229	& ln_bsyncro, fctamp, rn_maxlat_bias, rn_minlat_bias, &
230	& nn_bias_itwrt, ln_itdecay, ln_incpc,ln_incpc_only, ztscale, zwgt
231
232
233	!-----------------------------------------------------------------------
234	! Read Namelist : bias interface
235	!-----------------------------------------------------------------------
236
237
238	REWIND( numnam_ref ) ! Namelist nambias in reference namelist : Bias pressure correction
239	READ ( numnam_ref, nambias, IOSTAT = ios, ERR = 901)
240	901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nambias in reference namelist', lwp )
241
242
243	! Set additional default values (note that most values are set in the reference namelist)
244
245	IF ( ln_asmiau ) nn_bias_itwrt = nitiaufin
246
247	! ... default values (NB: frequency positive => hours, negative => months)
248	! ! file ! frequency ! variable ! time intep ! clim ! 'yearly' or !
249	! ! name ! (hours) ! name ! (T/F) ! (T/F) ! 'monthly' !
250	sn_tbias_ofl = FLD_N( 'tbias_ofl' , -1. , 'tbias' , .TRUE. , .FALSE. , 'yearly', '', '', '' )
251	sn_sbias_ofl = FLD_N( 'sbias_ofl' , -1. , 'sbias' , .TRUE. , .FALSE. , 'yearly', '', '', '' )
252
253
254	REWIND( numnam_cfg ) ! Namelist nambias in configuration namelist : Bias pressure correction
255	READ ( numnam_cfg, nambias, IOSTAT = ios, ERR = 902 )
256	902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nambias in configuration namelist', lwp )
257	IF(lwm) WRITE ( numond, nambias )
258
259
260	IF ( ( .NOT. ln_bias_asm ) .AND. ( .NOT. ln_bias_ofl ) .AND. ( .NOT. ln_bias_rlx ) ) THEN
261	ln_bias_ts_app = .FALSE.
262	ln_bias_pc_app = .FALSE.
263	ln_bias = .FALSE.
264	ENDIF
265
266	! set up decay scales
267	log2 = LOG( 2.0_wp )
268	t_rlx_mem = EXP( - log2 * rdt / ( eft_rlx * rday ) )
269	t_asm_mem = EXP( - log2 * bias_time_unit_asm/ ( eft_asm * rday ) )
270
271	! Control print
272	IF(lwp) THEN
273	WRITE(numout,*)
274	WRITE(numout,*) 'bias_init : '
275	WRITE(numout,*) '~~~~~~~~~~~ '
276	WRITE(numout,*) ' Namelist nambias : '
277
278	WRITE(numout,*) ' Bias switches/options/variables '
279	WRITE(numout,*) ' bias main switch ln_bias = ',ln_bias
280	WRITE(numout,*) ' bias from assim ln_bias_asm = ',ln_bias_asm
281	WRITE(numout,*) ' bias from relax ln_bias_rlx = ',ln_bias_rlx
282	WRITE(numout,*) ' bias from offln ln_bias_ofl = ',ln_bias_ofl
283	WRITE(numout,*) ' bias T and S apply ln_bias_ts_app = ',ln_bias_ts_app
284	WRITE(numout,*) ' bias pressure correctn apply ln_bias_pc_app = ',ln_bias_pc_app
285	WRITE(numout,*) ' lat ramp for bias correction nn_lat_ramp = ',nn_lat_ramp
286	WRITE(numout,*) ' time step for writing bias fld nn_bias_itwrt = ',nn_bias_itwrt
287	WRITE(numout,*) ' evolve pcbias at each timestep ln_itdecay = ',ln_itdecay
288	WRITE(numout,*) ' incremental press. correction ln_incpc = ',ln_incpc
289	WRITE(numout,*) ' incremental press. correction only ln_incpc_only = ',ln_incpc_only
290	WRITE(numout,*) ' incremental press. correction zwgt = ',zwgt
291	WRITE(numout,*) ' incremental press. correction ztscale = ',ztscale
292	WRITE(numout,*) ' Parameters for parition of bias term '
293	WRITE(numout,*) ' fb_t_rlx = ',fb_t_rlx
294	WRITE(numout,*) ' fb_t_asm = ',fb_t_asm
295	WRITE(numout,*) ' fb_t_ofl = ',fb_t_ofl
296	WRITE(numout,*) ' fb_p_rlx = ',fb_p_rlx
297	WRITE(numout,*) ' fb_p_asm = ',fb_p_asm
298	WRITE(numout,*) ' fb_p_ofl = ',fb_p_ofl
299	WRITE(numout,*) ' Parameters for time evolution of bias '
300	WRITE(numout,) ' Rlx efolding time (mem) eft_rlx,t_rlx_mem = ', eft_rlx, t_rlx_mem, 1. - log2 rdt / (eft_rlx * rday)
301	WRITE(numout,*) ' uptdate factor t_rlx_upd = ',t_rlx_upd
302	WRITE(numout,) ' Asm efolding time (mem) eft_asm,t_asm_mem = ', eft_asm, t_asm_mem, 1. - log2 rdt / (eft_asm * rday)
303	WRITE(numout,*) ' uptdate factor t_asm_upd = ',t_asm_upd
304	WRITE(numout,*) ' Filenames and input structures'
305	WRITE(numout,*) ' bias_tot filename cn_bias_to = ',cn_bias_tot
306	WRITE(numout,*) ' bias_asm filename cn_bias_asm = ',cn_bias_asm
307	WRITE(numout,*) ' bias_asm time unit (secs) bias_time_unit_asm = ',bias_time_unit_asm
308	WRITE(numout,*) ' structure Tem bias ofl sn_tbias_ofl = ',sn_tbias_ofl
309	WRITE(numout,*) ' structure Sal bias ofl sn_sbias_ofl = ',sn_sbias_ofl
310
311	IF ( ( (.NOT. ln_tsd_tradmp) .OR. (.NOT. ln_tradmp) ) .AND. ln_bias_rlx ) &
312	& CALL ctl_stop (' lk_dtatem, lk_dtasal and lk_tradmp need to be true with ln_bias_rlx' )
313
314	IF ( (.NOT. ln_itdecay) .AND. ln_incpc) &
315	& CALL ctl_stop (' if you set ln_incpc to .true. then you need to set ln_itdecay to .true. as well' )
316
317	IF ( (.NOT. ln_incpc) .AND. ln_incpc_only) &
318	& CALL ctl_stop (' if you set ln_incpc_only to .true. then you need to set ln_incpc to .true. as well' )
319
320	WRITE(numout,*) ' time step is = ',rdt,'you choose to write pcbias at nn_bias_itwrt = ',nn_bias_itwrt,'and end of iau is rday/rdt=',rday/rdt
321	ENDIF
322	IF( .NOT. ln_bias ) RETURN
323
324	IF( .NOT. lalloc ) THEN
325
326	ALLOCATE( tbias(jpi,jpj,jpk) , &
327	& sbias(jpi,jpj,jpk) , &
328	& tbias_p(jpi,jpj,jpk), &
329	& sbias_p(jpi,jpj,jpk), &
330	& tbias_i(jpi,jpj,jpk), &
331	& sbias_i(jpi,jpj,jpk), &
332	& rhd_pc(jpi,jpj,jpk) , &
333	& gru_pc(jpi,jpj) , &
334	& grv_pc(jpi,jpj) )
335
336	ALLOCATE( fbcoef(jpi,jpj), fbcoef_stscale(jpi,jpj) )
337
338	IF( ln_bias_asm ) ALLOCATE( tbias_asm(jpi,jpj,jpk), &
339	& sbias_asm(jpi,jpj,jpk), &
340	tbias_asm_out(jpi,jpj,jpk), &
341	sbias_asm_out(jpi,jpj,jpk), &
342	tbias_p_out(jpi,jpj,jpk), &
343	sbias_p_out(jpi,jpj,jpk) )
344
345	IF( ln_bias_rlx ) ALLOCATE( tbias_rlx(jpi,jpj,jpk), &
346	& sbias_rlx(jpi,jpj,jpk), &
347	tbias_rlx_out(jpi,jpj,jpk), &
348	sbias_rlx_out(jpi,jpj,jpk) )
349
350	IF( ln_incpc ) ALLOCATE( tbias_asm_stscale(jpi,jpj,jpk), &
351	& sbias_asm_stscale(jpi,jpj,jpk), &
352	tbias_asm_stscale_out(jpi,jpj,jpk), &
353	sbias_asm_stscale_out(jpi,jpj,jpk), &
354	tbias_i_out(jpi,jpj,jpk), &
355	sbias_i_out(jpi,jpj,jpk) )
356
357	lalloc = .TRUE.
358
359	ENDIF
360
361	IF( ln_bias_ofl ) THEN ! set sf_tbias_ofl and sf_sbias_ofl strctrs
362	!
363	! tbias
364	!
365	ALLOCATE( sf_tbias_ofl(1), STAT=ierror )
366	IF( ierror > 0 ) THEN
367	CALL ctl_stop( 'bias_init: unable to allocate sf_tbias_ofl structure' ) ; RETURN
368	ENDIF
369	ALLOCATE( sf_tbias_ofl(1)%fnow(jpi,jpj,jpk) )
370	ALLOCATE( sf_tbias_ofl(1)%fdta(jpi,jpj,jpk,2) )
371
372	! fill structure with values and control print
373	CALL fld_fill( sf_tbias_ofl, (/ sn_tbias_ofl /), cn_dir, 'bias_init', 'Offline T bias term ', 'nam_tbias_ofl' )
374	!
375	! salinity bias
376	!
377	ALLOCATE( sf_sbias_ofl(1), STAT=ierror )
378	IF( ierror > 0 ) THEN
379	CALL ctl_stop( 'bias_init: unable to allocate sf_sbias_ofl structure' ) ; RETURN
380	ENDIF
381	ALLOCATE( sf_sbias_ofl(1)%fnow(jpi,jpj,jpk) )
382	ALLOCATE( sf_sbias_ofl(1)%fdta(jpi,jpj,jpk,2) )
383
384	! fill structure with values and control print
385	CALL fld_fill( sf_sbias_ofl, (/ sn_sbias_ofl /), cn_dir, 'bias_init', 'Offline S bias term ', 'nam_sbias_ofl' )
386
387	ENDIF
388
389	! Read total bias
390	IF ( ln_bias ) THEN
391	tbias(:,:,:) = 0.0_wp
392	sbias(:,:,:) = 0.0_wp
393	tbias_p(:,:,:) = 0.0_wp
394	sbias_p(:,:,:) = 0.0_wp
395	tbias_i(:,:,:) = 0.0_wp
396	sbias_i(:,:,:) = 0.0_wp
397	gru_pc(:,:) = 0.0_wp
398	grv_pc(:,:) = 0.0_wp
399
400	IF ( ln_bias_rlx ) THEN
401	tbias_rlx(:,:,:) = 0.0_wp
402	sbias_rlx(:,:,:) = 0.0_wp
403	ENDIF
404
405	IF ( ln_bias_asm ) THEN !now rlx and asm bias in same file
406	tbias_asm(:,:,:) = 0.0_wp
407	sbias_asm(:,:,:) = 0.0_wp
408	tbias_asm_out(:,:,:) = 0.0_wp
409	sbias_asm_out(:,:,:) = 0.0_wp
410	ENDIF
411
412	IF ( ln_incpc ) THEN !incr pressure correction
413	tbias_asm_stscale(:,:,:) = 0.0_wp
414	sbias_asm_stscale(:,:,:) = 0.0_wp
415	tbias_asm_stscale_out(:,:,:) = 0.0_wp
416	sbias_asm_stscale_out(:,:,:) = 0.0_wp
417	ENDIF
418
419
420	numbias_tot = 0
421	! Get bias from file and prevent fail if the file does not exist
422	IF(lwp) WRITE(numout,*) 'Opening ',TRIM( cn_bias_tot )
423	CALL iom_open( cn_bias_tot, numbias_tot, ldstop=.FALSE. )
424
425	IF ( numbias_tot > 0 ) THEN
426	! Could check validity time of bias fields here...
427	! Get the T and S bias data
428	IF(lwp) WRITE(numout,*) 'Reading bias fields from tot...'
429
430	!Search for bias from relaxation term if needed. Use same file
431	IF ( ln_bias_rlx ) THEN
432	IF(lwp) WRITE(numout,*) 'Reading bias fields for bias rlx from file ',cn_bias_tot
433	IF( iom_varid( numbias_tot, 'tbias_rlx' ) > 0 ) THEN
434	! Get the T and S bias data
435	CALL iom_get( numbias_tot, jpdom_autoglo, 'tbias_rlx', tbias_rlx )
436	CALL iom_get( numbias_tot, jpdom_autoglo, 'sbias_rlx', sbias_rlx )
437	ELSE
438	CALL ctl_stop( 'Bias relaxation variables not found in ',cn_bias_tot )
439	ENDIF
440	ENDIF
441
442
443	!Search for bias from assim term if needed. Use same file
444	IF ( ln_bias_asm .and. .not.ln_bsyncro ) THEN
445	IF(lwp) WRITE(numout,*) 'Reading a-syncro bias fields for bias asm from file ',cn_bias_tot
446	IF( iom_varid( numbias_tot, 'tbias_asm' ) > 0 ) THEN
447	! Get the T and S bias data
448	CALL iom_get( numbias_tot, jpdom_autoglo, 'tbias_asm', tbias_asm )
449	CALL iom_get( numbias_tot, jpdom_autoglo, 'sbias_asm', sbias_asm )
450	ELSE
451	CALL ctl_stop( 'Bias assim variables not found in ',cn_bias_tot )
452	ENDIF
453	ENDIF
454
455	IF ( ln_incpc .and. .not.ln_bsyncro ) THEN
456	IF(lwp) WRITE(numout,*) 'Reading short time scale bias correction fields for bias asm from file ',cn_bias_tot
457	IF( iom_varid( numbias_tot, 'tbias_asm_stscale' ) > 0 ) THEN
458	! Get the T and S bias data
459	CALL iom_get( numbias_tot, jpdom_autoglo, 'tbias_asm_stscale', tbias_asm_stscale )
460	CALL iom_get( numbias_tot, jpdom_autoglo, 'sbias_asm_stscale', sbias_asm_stscale )
461	ELSE
462	CALL ctl_stop( 'Short time scale bias assim variables not found in ',cn_bias_tot )
463	ENDIF
464	ENDIF
465
466
467
468	! Close the file
469	CALL iom_close(numbias_tot)
470
471	ELSE
472	IF(lwp) WRITE(numout,*) 'No bias file found so T and S bias fields are set to zero'
473	ENDIF
474
475	ENDIF
476
477	! for the time being, the bias_asm is read in the same file as
478	! bias_rlx
479	! Implications: bias_asm is estimated/evolved in time in the second outer
480	! loop only, when the assimilation increments are ready.
481	! bias_asm is kept cte during the first outer loop.
482	! => Assyncronous bias correction.
483	! Alternative: Syncronous bias correction:
484	! bias_asm estimated/evolved in the first outer loop
485	! with the asm incrments of the previous cycle.
486	! bias_asm kept cte during the second outer loop.
487	! Implication: bias_asm should be estimated really in the
488	! inner loop.
489	IF ( ln_bsyncro ) THEN
490	! Read bias from assimilation from a separate file
491	IF ( ln_bias_asm ) THEN
492	tbias_asm(:,:,:) = 0.0_wp
493	sbias_asm(:,:,:) = 0.0_wp
494	numbias_asm = 0
495	! Get bias from file and prevent fail if the file does not exist
496	IF(lwp) WRITE(numout,*) 'Opening file for syncro assim bias ',TRIM( cn_bias_asm )
497	CALL iom_open( cn_bias_asm, numbias_asm, ldstop=.FALSE. )
498
499	IF ( numbias_asm > 0 ) THEN
500	! Could check validity time of bias fields here...
501
502	! Get the T and S bias data
503	IF(lwp) WRITE(numout,*) 'Reading syncro bias fields from asm from file ',cn_bias_asm
504	CALL iom_get( numbias_asm, jpdom_autoglo, 'tbias_asm', tbias_asm )
505	CALL iom_get( numbias_asm, jpdom_autoglo, 'sbias_asm', sbias_asm )
506
507	! this is only applicable if tbias_asm were to be calculated in the inner loop
508	tbias_asm(:,:,:) = tbias_asm(:,:,:) * rdt / bias_time_unit_asm
509	sbias_asm(:,:,:) = sbias_asm(:,:,:) * rdt / bias_time_unit_asm
510
511	! Close the file
512	CALL iom_close(numbias_asm)
513
514	ELSE
515	IF(lwp) WRITE(numout,*) 'No bias file found from asm so T and S bias fields are set to zero'
516	ENDIF
517
518	ENDIF
519
520	ENDIF
521
522	!latitudinal dependence of partition coeficients. Adhoc
523	IF ( nn_lat_ramp == 1 ) THEN
524	! Use the inertial ramp.
525	lenscl_bias = ( rn_maxlat_bias - rn_minlat_bias )*2._wp
526	fbcoef(:,:) = 1._wp - exp( -( abs( gphit(:,:) ) - rn_minlat_bias ) &
527	* ( abs( gphit(:,:) ) - rn_minlat_bias ) / lenscl_bias )
528	WHERE ( abs( gphit(:,:) ) <= rn_minlat_bias )
529	fbcoef(:,:) = 0._wp
530	ENDWHERE
531	WHERE ( abs( gphit(:,:) ) >= rn_maxlat_bias )
532	fbcoef(:,:) = 1._wp
533	ENDWHERE
534
535	ELSEIF ( nn_lat_ramp == 2 ) THEN
536	! Use a linear ramp consist with the geostrophic velocity balance ramp in NEMOVAR
537
538	fbcoef(:,:) = 1._wp - ((rn_maxlat_bias - abs( gphit(:,:)))/(rn_maxlat_bias - rn_minlat_bias))
539	WHERE ( abs( gphit(:,:) ) <= rn_minlat_bias )
540	fbcoef(:,:) = 0._wp
541	ENDWHERE
542	WHERE ( abs( gphit(:,:) ) >= rn_maxlat_bias )
543	fbcoef(:,:) = 1._wp
544	ENDWHERE
545
546
547	ELSE
548	fbcoef(:,:) = 0.0_wp
549	fctamp = 0.0_wp
550	fbcoef_stscale(:,:) = 0.0_wp
551	ENDIF
552
553
554	IF ( ln_incpc) THEN
555	minlat_bias = 3.0_wp
556	maxlat_bias = 8.0_wp
557	WHERE ( abs( gphit(:,:) ) <= minlat_bias )
558	fbcoef_stscale(:,:)=0._wp
559	ELSEWHERE ( abs( gphit(:,:) ) >= maxlat_bias )
560	fbcoef_stscale(:,:)=1._wp
561	ELSEWHERE
562	fbcoef_stscale(:,:)=1._wp - ((maxlat_bias - abs( gphit(:,:)))/(maxlat_bias-minlat_bias))
563	ENDWHERE
564	ENDIF
565
566
567	END SUBROUTINE bias_init
568
569	SUBROUTINE tra_bias ( kt )
570	!!----------------------------------------------------------------------
571	!! * ROUTINE tra_bias *
572	!!
573	!! ** Purpose : Update bias field every time step
574	!!
575	!! ** Method : add contributions to bias from 3 terms
576	!!
577	!! ** Action : Bias from assimilation (read in bias_init)
578	!! Bias from relaxation term is estimated according to
579	!! the prescribed time evolution of the bias
580	!! Bias from ofl term is read from external file
581	!! The difference contributions are added and the partition
582	!! into direct bias in T/S and pressure perfomed.
583	!!
584	!! History : 09-03 (M. Balmaseda)
585	!!----------------------------------------------------------------------
586	!! called every timestep after dta_sst if ln_bias true.
587
588	IMPLICIT NONE
589
590	!! * Arguments
591	INTEGER, INTENT(IN) :: kt ! ocean time-step index
592	!! * Local variables
593	INTEGER :: ji,jj,jk, it ! local loop index
594	REAL(wp) :: tsclf ! time saling factor
595	REAL(wp) :: fb_t_asm_max, fb_t_rlx_max, fb_t_ofl_max
596	REAL(wp) :: ztfrac, ztsday
597	REAL(wp) :: zfrac, zfrac1 ! temporal weights for inst pcbias (names could be changed)
598	REAL(wp) :: zdecay ! used in inst pcorr
599	REAL(wp), DIMENSION(jpi,jpj) :: zcof1, zcof2
600
601	IF ( .NOT. ln_bias ) RETURN
602	fb_t_rlx_max = MIN(fb_t_rlx*fctamp,1.0_wp)
603	fb_t_asm_max = MIN(fb_t_asm*fctamp,1.0_wp)
604	fb_t_ofl_max = MIN(fb_t_ofl*fctamp,1.0_wp)
605
606	tbias(:,:,:) = 0.0_wp
607	sbias(:,:,:) = 0.0_wp
608	tbias_p(:,:,:) = 0.0_wp
609	sbias_p(:,:,:) = 0.0_wp
610	tbias_i(:,:,:) = 0.0_wp
611	sbias_i(:,:,:) = 0.0_wp
612
613	IF ( ln_bias_asm ) THEN
614
615	tsclf = 1
616	IF ( .NOT.ln_bsyncro ) tsclf = rdt / bias_time_unit_asm
617	zcof1(:,:) = tsclf * ( ( 1.0_wp - fbcoef(:,:) ) * fb_t_asm + &
618	& fbcoef(:,:) * fb_t_asm_max )
619	zcof2(:,:) = ( 1.0_wp - fbcoef(:,:) ) * fb_p_asm
620
621	IF ( ln_itdecay ) THEN !decay the pressure correction at each time step
622
623	ztsday = rday / REAL(rdt,wp)
624
625	zdecay = (1-ztscale)**(1/REAL(ztsday,wp)) ! used in ipc
626	zfrac1 = zdecay**REAL(kt,wp) ! used in ipc
627	IF ( zfrac1 <= 0.0 ) zfrac1 = 0.0_wp
628
629	IF( ln_asmiau .and. ln_trainc ) THEN ! nudge in increments and decay historical contribution
630
631	IF ( kt <= nitiaufin ) THEN ! During IAU calculate the fraction of increments to apply at each time step
632
633	ztfrac = REAL(kt,wp) / REAL(nitiaufin,wp) ! nudging factor during the IAU
634
635	IF (lwp) THEN
636	WRITE(numout,*) 'tra_bias : bias weights'
637	WRITE(numout,*) '~~~~~~~~~~~~'
638	WRITE(numout,* ) "proportion of increment applied in pcbias ",ztfrac
639	WRITE(numout,* ) "proportion of historical pcbias applied ",t_asm_mem**(REAL(kt,wp)/ztsday)
640	ENDIF
641
642	DO jk = 1, jpkm1
643	tbias(:,:,jk) = tbias(:,:,jk) + &
644	& ( t_asm_mem*(REAL(kt,wp)/ztsday) tbias_asm(:,:,jk) + &
645	& ztfrac * t_asm_upd * t_bkginc(:,:,jk) * tmask(:,:,jk) ) * zcof1(:,:)
646	sbias(:,:,jk) = sbias(:,:,jk) + &
647	& ( t_asm_mem*(REAL(kt,wp)/ztsday) sbias_asm(:,:,jk) + &
648	& ztfrac * t_asm_upd * s_bkginc(:,:,jk) * tmask(:,:,jk) ) * zcof1(:,:)
649
650	tbias_p(:,:,jk) = tbias_p(:,:,jk) + &
651	& ( t_asm_mem*(REAL(kt,wp)/ztsday) tbias_asm(:,:,jk) + &
652	& ztfrac * t_asm_upd * t_bkginc(:,:,jk) * tmask(:,:,jk) ) * zcof2(:,:)
653	sbias_p(:,:,jk) = sbias_p(:,:,jk) + &
654	& ( t_asm_mem*(REAL(kt,wp)/ztsday) sbias_asm(:,:,jk) + &
655	& ztfrac * t_asm_upd * s_bkginc(:,:,jk) * tmask(:,:,jk) ) * zcof2(:,:)
656	ENDDO
657
658	IF (ln_incpc) THEN
659
660	IF (lwp) THEN
661	WRITE(numout,*) 'tra_bias : bias weights'
662	WRITE(numout,*) '~~~~~~~~~~~~'
663	WRITE(numout,* ) "IPC - proportion of increment applied in pcbias ",ztfrac
664	WRITE(numout,* ) "IPC - proportion of historical pcbias applied ",zfrac1
665	ENDIF
666
667	DO jk = 1, jpkm1
668
669	tbias_i(:,:,jk) = ( t_bkginc(:,:,jk) * tmask(:,:,jk)* zwgt * ztfrac * (1.0 - fbcoef_stscale(:,:)) ) &
670	& + ( tbias_asm_stscale(:,:,jk) * zfrac1 * (1.0 - fbcoef_stscale(:,:)) )
671	sbias_i(:,:,jk) = ( s_bkginc(:,:,jk) * tmask(:,:,jk)* zwgt * ztfrac * (1.0 - fbcoef_stscale(:,:)) ) &
672	& + ( sbias_asm_stscale(:,:,jk) * zfrac1 * (1.0 - fbcoef_stscale(:,:)) )
673
674	ENDDO
675
676	ENDIF
677
678	IF ( .not.ln_bsyncro ) THEN
679
680	IF ( kt == nn_bias_itwrt ) THEN
681
682	DO jk = 1, jpkm1
683	tbias_asm_out(:,:,jk) = t_asm_mem*(REAL(kt,wp)/ztsday) tbias_asm(:,:,jk) + &
684	& ztfrac * t_asm_upd * t_bkginc(:,:,jk) * tmask(:,:,jk)
685	sbias_asm_out(:,:,jk) = t_asm_mem*(REAL(kt,wp)/ztsday) sbias_asm(:,:,jk) + &
686	& ztfrac * t_asm_upd * s_bkginc(:,:,jk) * tmask(:,:,jk)
687	END DO
688
689	IF ( ln_incpc) THEN
690	DO jk = 1, jpkm1
691	tbias_asm_stscale_out(:,:,jk) = ( t_bkginc(:,:,jk) * tmask(:,:,jk) * zwgt * ztfrac ) + ( tbias_asm_stscale(:,:,jk) * zfrac1 )
692	sbias_asm_stscale_out(:,:,jk) = ( s_bkginc(:,:,jk) * tmask(:,:,jk) * zwgt * ztfrac ) + ( sbias_asm_stscale(:,:,jk) * zfrac1 )
693	ENDDO
694	ENDIF
695
696	ENDIF
697
698	ENDIF
699
700	! update the historical component with the increments at the end of the IAU
701	IF ( kt == nitiaufin ) THEN
702	DO jk = 1, jpkm1
703	tbias_asm(:,:,jk) = t_asm_mem*(REAL(kt,wp)/ztsday) tbias_asm(:,:,jk) + &
704	& ztfrac * t_asm_upd * t_bkginc(:,:,jk) * tmask(:,:,jk)
705	sbias_asm(:,:,jk) = t_asm_mem*(REAL(kt,wp)/ztsday) sbias_asm(:,:,jk) + &
706	& ztfrac * t_asm_upd * s_bkginc(:,:,jk) * tmask(:,:,jk)
707	END DO
708
709	IF (ln_incpc) THEN
710	DO jk = 1, jpkm1
711	tbias_asm_stscale(:,:,jk) = ( t_bkginc(:,:,jk) * tmask(:,:,jk) * zwgt * ztfrac ) + ( tbias_asm_stscale(:,:,jk) * zfrac1 )
712	sbias_asm_stscale(:,:,jk) = ( s_bkginc(:,:,jk) * tmask(:,:,jk) * zwgt * ztfrac ) + ( sbias_asm_stscale(:,:,jk) * zfrac1 )
713	ENDDO
714	ENDIF
715
716	ENDIF
717
718	ELSE ! decay pressure correction from combined historical component and increments after IAU
719
720	ztfrac=t_asm_mem**(REAL(kt-nitiaufin,wp)/REAL(nitiaufin,wp)) ! decay from end of IAU
721
722	DO jk = 1, jpkm1
723	tbias(:,:,jk) = tbias(:,:,jk) + &
724	& ( ztfrac * tbias_asm(:,:,jk) ) * zcof1(:,:)
725	sbias(:,:,jk) = sbias(:,:,jk) + &
726	& ( ztfrac * sbias_asm(:,:,jk) ) * zcof1(:,:)
727	tbias_p(:,:,jk) = tbias_p(:,:,jk) + &
728	& ( ztfrac * tbias_asm(:,:,jk) ) * zcof2(:,:)
729	sbias_p(:,:,jk) = sbias_p(:,:,jk) + &
730	& ( ztfrac * sbias_asm(:,:,jk) ) * zcof2(:,:)
731	ENDDO
732
733	IF (ln_incpc) THEN
734
735	zfrac = zdecay**REAL(kt-nitiaufin,wp)
736	IF ( zfrac <= 0.0 ) zfrac = 0.0_wp
737
738	DO jk = 1, jpkm1
739	tbias_i(:,:,jk) = tbias_asm_stscale(:,:,jk) * zfrac * (1.0 - fbcoef_stscale(:,:))
740	sbias_i(:,:,jk) = sbias_asm_stscale(:,:,jk) * zfrac * (1.0 - fbcoef_stscale(:,:))
741	ENDDO
742
743	IF (lwp) THEN
744	WRITE(numout,*) 'tra_bias : bias weights'
745	WRITE(numout,*) '~~~~~~~~~~~~'
746	WRITE(numout,* ) "IPC - proportion of increments + historical pcbias applied ",zfrac
747	ENDIF
748
749	ENDIF
750
751	IF (lwp) THEN
752	WRITE(numout,*) 'tra_bias : bias weights'
753	WRITE(numout,*) '~~~~~~~~~~~~'
754	WRITE(numout,* ) "proportion of increments + historical pcbias applied ",ztfrac
755	ENDIF
756
757	IF ( ln_trainc .and. .not.ln_bsyncro ) THEN
758	IF ( kt == nn_bias_itwrt ) THEN
759	DO jk = 1, jpkm1
760	tbias_asm_out(:,:,jk) = ztfrac * tbias_asm(:,:,jk)
761	sbias_asm_out(:,:,jk) = ztfrac * sbias_asm(:,:,jk)
762	END DO
763
764	IF ( ln_incpc ) THEN
765	IF (lwp) WRITE(numout,*) 'after end of IAU - IPC - saving s/tbias_asm_stscale'
766	DO jk = 1, jpkm1
767	tbias_asm_stscale_out(:,:,jk) = tbias_asm_stscale(:,:,jk) * zfrac
768	sbias_asm_stscale_out(:,:,jk) = sbias_asm_stscale(:,:,jk) * zfrac
769	ENDDO
770	ENDIF
771	ENDIF
772	ENDIF
773	ENDIF
774
775	ELSE ! no assimilation increments, simply decay pressure correction (e.g for forecasts)
776	! this occurs at obsoper step as well ( ln_asmiau is false )
777
778	DO jk = 1, jpkm1
779	tbias(:,:,jk) = tbias(:,:,jk) + &
780	& ( t_asm_mem*(REAL(kt,wp)/ztsday) tbias_asm(:,:,jk) ) * zcof1(:,:)
781	sbias(:,:,jk) = sbias(:,:,jk) + &
782	& ( t_asm_mem*(REAL(kt,wp)/ztsday) sbias_asm(:,:,jk) ) * zcof1(:,:)
783	tbias_p(:,:,jk) = tbias_p(:,:,jk) + &
784	& ( t_asm_mem*(REAL(kt,wp)/ztsday) tbias_asm(:,:,jk) ) * zcof2(:,:)
785	sbias_p(:,:,jk) = sbias_p(:,:,jk) + &
786	& ( t_asm_mem*(REAL(kt,wp)/ztsday) sbias_asm(:,:,jk) ) * zcof2(:,:)
787	ENDDO
788
789	IF (lwp) THEN
790	WRITE(numout,*) 'tra_bias : bias weights'
791	WRITE(numout,*) '~~~~~~~~~~~~'
792	WRITE(numout,* ) "proportion of historical pcbias applied ",t_asm_mem**(REAL(kt,wp)/ztsday)
793	ENDIF
794
795	IF (ln_incpc) THEN
796	IF (lwp) WRITE(numout,*) 'obsoper or forecast mode - IPC - computing tbias_i and sbias_i'
797	DO jk = 1, jpkm1
798	tbias_i(:,:,jk) = tbias_i(:,:,jk) + ( tbias_asm_stscale(:,:,jk) * zfrac1 * (1.0 - fbcoef_stscale(:,:)) )
799	sbias_i(:,:,jk) = sbias_i(:,:,jk) + ( sbias_asm_stscale(:,:,jk) * zfrac1 * (1.0 - fbcoef_stscale(:,:)) )
800	ENDDO
801	tbias_i(:,:,:) =tbias_i(:,:,:)*tmask(:,:,:)
802	sbias_i(:,:,:) =sbias_i(:,:,:)*tmask(:,:,:)
803	ENDIF
804	ENDIF
805
806	ELSE ! maintain a constant pressure correction
807
808	DO jk = 1, jpkm1
809	tbias(:,:,jk) = tbias(:,:,jk) + tbias_asm(:,:,jk) * zcof1(:,:)
810	sbias(:,:,jk) = sbias(:,:,jk) + sbias_asm(:,:,jk) * zcof1(:,:)
811	tbias_p(:,:,jk) = tbias_p(:,:,jk) + tbias_asm(:,:,jk) * zcof2(:,:)
812	sbias_p(:,:,jk) = sbias_p(:,:,jk) + sbias_asm(:,:,jk) * zcof2(:,:)
813	END DO
814
815	IF( ln_asmiau .and. ln_trainc .and. .not.ln_bsyncro ) THEN
816	! if last outer loop (ln_asmiau=true and ln_trainc=true). t/sbias_asm
817	! is updated, only once (end of run) taking into account units.
818	IF ( kt == nn_bias_itwrt ) THEN
819	IF(lwp) WRITE(numout,*)' estimating asm bias at timestep: ',kt
820	DO jk = 1, jpkm1
821	tbias_asm_out(:,:,jk) = t_asm_mem * tbias_asm(:,:,jk) + &
822	& t_asm_upd * t_bkginc(:,:,jk) * tmask(:,:,jk)
823	sbias_asm_out(:,:,jk) = t_asm_mem * sbias_asm(:,:,jk) + &
824	& t_asm_upd * s_bkginc(:,:,jk) * tmask(:,:,jk)
825	END DO
826	ENDIF
827	ENDIF
828
829	ENDIF
830
831	ENDIF
832
833
834	#if defined key_tradmp
835	! Time evolution of bias from relaxation
836	IF ( ln_bias_rlx ) THEN
837	tbias_rlx(:,:,:) = t_rlx_mem * tbias_rlx(:,:,:) + &
838	& t_rlx_upd * ttrdmp(:,:,:) * rdt
839	sbias_rlx(:,:,:) = t_rlx_mem * sbias_rlx(:,:,:) + &
840	& t_rlx_upd * strdmp(:,:,:) * rdt
841	zcof1(:,:) = ( 1.0_wp - fbcoef(:,:) ) * fb_t_rlx + &
842	& fbcoef(:,:) * fb_t_rlx_max
843	zcof2(:,:) = ( 1.0_wp - fbcoef(:,:) ) * fb_p_rlx
844	DO jk = 1, jpkm1
845	tbias(:,:,jk) = tbias(:,:,jk) + tbias_rlx(:,:,jk) * zcof1(:,:)
846	sbias(:,:,jk) = sbias(:,:,jk) + sbias_rlx(:,:,jk) * zcof1(:,:)
847	tbias_p(:,:,jk) = tbias_p(:,:,jk) + tbias_rlx(:,:,jk) * zcof2(:,:)
848	sbias_p(:,:,jk) = sbias_p(:,:,jk) + sbias_rlx(:,:,jk) * zcof2(:,:)
849	ENDDO
850	IF ( kt == nn_bias_itwrt ) THEN
851	tbias_rlx_out(:,:,:) = tbias_rlx(:,:,:)
852	sbias_rlx_out(:,:,:) = sbias_rlx(:,:,:)
853	ENDIF
854	ENDIF
855	#endif
856	! ofline bias
857	IF ( kt == nit000 ) THEN
858	IF(lwp) WRITE(numout,*) ' tra_bias: ln_bias_ofl = ',ln_bias_ofl
859	IF(lwp) WRITE(numout,*) ' ~~~~~~~~~'
860	ENDIF
861	IF ( ln_bias_ofl ) THEN
862	IF(lwp) WRITE(numout,*) 'reading offline bias'
863	CALL fld_read( kt, 1, sf_tbias_ofl )
864	CALL fld_read( kt, 1, sf_sbias_ofl )
865
866	zcof1(:,:) = ( 1.0_wp - fbcoef(:,:) ) * fb_t_ofl + &
867	& fbcoef(:,:) * fb_t_ofl_max
868	zcof2(:,:) = ( 1.0_wp - fbcoef(:,:) ) * fb_p_ofl
869	DO jk = 1, jpkm1
870	tbias(:,:,jk) = tbias(:,:,jk) + sf_tbias_ofl(1)%fnow(:,:,jk) * zcof1(:,:)
871	sbias(:,:,jk) = sbias(:,:,jk) + sf_sbias_ofl(1)%fnow(:,:,jk) * zcof1(:,:)
872	tbias_p(:,:,jk) = tbias_p(:,:,jk) + sf_tbias_ofl(1)%fnow(:,:,jk) * zcof2(:,:)
873	sbias_p(:,:,jk) = sbias_p(:,:,jk) + sf_sbias_ofl(1)%fnow(:,:,jk) * zcof2(:,:)
874	ENDDO
875	ENDIF
876
877
878	!apply bias on tracers if needed
879	IF ( ln_bias_ts_app ) THEN
880
881	! Add the bias directely to T/s
882	tsa(:,:,:,jp_tem) = tsa(:,:,:,jp_tem) + tmask(:,:,:) * tbias(:,:,:) / rdt
883	tsa(:,:,:,jp_sal) = tsa(:,:,:,jp_sal) + tmask(:,:,:) * sbias(:,:,:) / rdt
884
885	! lateral boundary conditions (is this needed?)
886	CALL lbc_lnk( tsa(:,:,:,jp_tem), 'T', 1.0_wp )
887	CALL lbc_lnk( tsa(:,:,:,jp_sal), 'T', 1.0_wp )
888
889	ENDIF
890
891	IF ( kt == nn_bias_itwrt ) THEN
892	tbias_p_out(:,:,:) = tbias_p(:,:,:)
893	sbias_p_out(:,:,:) = sbias_p(:,:,:)
894	IF (ln_incpc) THEN
895	tbias_i_out(:,:,:) = tbias_i(:,:,:)
896	sbias_i_out(:,:,:) = sbias_i(:,:,:)
897	ENDIF
898	ENDIF
899
900	END SUBROUTINE tra_bias
901
902	SUBROUTINE dyn_bias( kt )
903	!!----------------------------------------------------------------------
904	!! * ROUTINE dyn_bias *
905	!!
906	!! ** Purpose : Computes rhd_pc, gru/v_pc bias corrected
907	!! for hydrostatic pressure gradient
908	!! depending on time step (semi-implicit/centered)
909	!! If partial steps computes bottom pressure gradient.
910	!! These correction terms will affect only the dynamical
911	!! component (pressure gradient calculation), but not
912	!! the isopycnal calculation for the lateral mixing.
913	!!
914	!! ** Method : At this stage of the computation, ta and sa are the
915	!! after temperature and salinity. If semi-implicit, these
916	!! are used to compute rho and bottom pressure gradient.
917	!! If centered, tb,sb are used instead.
918	!! If bias key is activated, the temperature,salinity are
919	!! bias corrected in the calculation of the density fields
920	!! used in the pressure gradient calculation.
921	!!
922	!!
923	!! ** Action : - rhd_pc ready. rhop will be overwriten later
924	!! - if ln_zps, bottom density gradients gru/v_pc ready.
925	!!----------------------------------------------------------------------
926	!!
927	!! * Arguments
928	INTEGER, INTENT(IN) :: kt ! ocean time-step index
929	!! * Local variables
930	REAL(wp) :: tsw(jpi,jpj,jpk,jpts)
931	!!
932	!!----------------------------------------------------------------------
933	!
934	! gtu,gsu,gtv,gsv rhop will be overwritten later in step.
935	!
936	IF( ln_dynhpg_imp ) THEN ! semi-implicit hpg
937	tsw(:,:,:,jp_tem) = tsa(:,:,:,jp_tem) - tbias_p(:,:,:)
938	tsw(:,:,:,jp_sal) = tsa(:,:,:,jp_sal) - sbias_p(:,:,:)
939	IF ( ln_incpc ) THEN
940	tsw(:,:,:,jp_tem) = tsa(:,:,:,jp_tem) - tbias_p(:,:,:) - tbias_i(:,:,:)
941	tsw(:,:,:,jp_sal) = tsa(:,:,:,jp_sal) - sbias_p(:,:,:) - sbias_i(:,:,:)
942	IF ( ln_incpc_only ) THEN
943	IF(lwp) WRITE(numout,*) 'ln_incpc_only =', ln_incpc_only, 'tsw updated with IPC only and ln_dynhpg_imp = ',ln_dynhpg_imp
944	tsw(:,:,:,jp_tem) = tsa(:,:,:,jp_tem) - tbias_i(:,:,:)
945	tsw(:,:,:,jp_sal) = tsa(:,:,:,jp_sal) - sbias_i(:,:,:)
946	ENDIF
947	ENDIF
948	ELSE
949	tsw(:,:,:,jp_tem) = tsb(:,:,:,jp_tem) - tbias_p(:,:,:)
950	tsw(:,:,:,jp_sal) = tsb(:,:,:,jp_sal) - sbias_p(:,:,:)
951	IF ( ln_incpc ) THEN
952	tsw(:,:,:,jp_tem) = tsb(:,:,:,jp_tem) - tbias_p(:,:,:) - tbias_i(:,:,:)
953	tsw(:,:,:,jp_sal) = tsb(:,:,:,jp_sal) - sbias_p(:,:,:) - sbias_i(:,:,:)
954	IF ( ln_incpc_only ) THEN
955	IF(lwp) WRITE(numout,*) 'ln_incpc_only =', ln_incpc_only, 'tsw updated with IPC only and ln_dynhpg_imp = ',ln_dynhpg_imp
956	tsw(:,:,:,jp_tem) = tsb(:,:,:,jp_tem) - tbias_i(:,:,:)
957	tsw(:,:,:,jp_sal) = tsb(:,:,:,jp_sal) - sbias_i(:,:,:)
958	ENDIF
959	ENDIF
960	ENDIF
961
962	IF(lwp) WRITE(numout,*) 'dyn_bias( kt ) calculating rhd_pc, kt =', kt
963	CALL eos( tsw, rhd_pc, rhop, fsdept_n(:,:,:) )
964
965	CALL lbc_lnk( rhd_pc, 'T', 1.0_wp )
966
967
968	! Partial steps: now horizontal gradient of t,s,rd
969	! at the bottom ocean level
970
971	IF( ln_zps ) THEN
972	CALL zps_hde( kt, jpts, tsw, gtsu, gtsv, &
973	& rhd_pc, gru_pc , grv_pc )
974	ENDIF
975
976	END SUBROUTINE dyn_bias
977
978	SUBROUTINE bias_opn( kt )
979	!!---------------------------------------------------------------------
980	!! * ROUTINE bias_opn *
981	!!
982	!! ** Purpose : open bias restart file following the same logic as the
983	!! standard restarts.
984	!!----------------------------------------------------------------------
985	!! * Arguments
986	INTEGER, INTENT(IN) :: kt ! ocean time-step
987	!! * Local variables
988	CHARACTER(LEN=20) :: clbkt ! ocean time-step deine as a character
989	CHARACTER(LEN=50) :: clbias_tot ! total bias restart file name
990	!!----------------------------------------------------------------------
991	!
992	IF( lrst_oce .AND. .NOT.lrst_bias ) THEN ! create bias file
993	IF( nitend > 999999999 ) THEN ; WRITE(clbkt, * ) nitend
994	ELSE ; WRITE(clbkt, '(i8.8)') nitend
995	ENDIF
996	clbias_tot = TRIM(cexper)//"_"//TRIM(ADJUSTL(clbkt))//"_"//TRIM(cn_bias_tot)
997	IF(lwp) THEN
998	WRITE(numout,*)
999	SELECT CASE ( jprstlib )
1000	CASE ( jprstdimg ) ; WRITE(numout,*) ' open tot bias restart binary file: '//clbias_tot
1001	CASE DEFAULT ; WRITE(numout,*) ' open tot bias restart NetCDF file: '//clbias_tot
1002	END SELECT
1003	ENDIF
1004	CALL iom_open( clbias_tot, numbias_tot , ldwrt = .TRUE., kiolib = jprstlib )
1005	lrst_bias=.TRUE.
1006
1007	ENDIF
1008	!
1009	END SUBROUTINE bias_opn
1010
1011	SUBROUTINE bias_wrt( kt )
1012	!!---------------------------------------------------------------------
1013	!! * ROUTINE bias_wrt *
1014	!!
1015	!! ** Purpose : Write bias restart fields in the format corresponding to jprstlib
1016	!!
1017	!! ** Method : Write in numbias_tot when kt == nitend in output
1018	!! file, save fields which are necessary for restart.
1019	!!
1020	!! Changed the timestep for writing to nitend rather than nitrst as this causes a
1021	!! problem if the nstock list is used to determine the restart output times and
1022	!! means that the bias is not output at all. M. Martin. 08/2011.
1023	!! Need to check with Magdalena that this is ok for ECMWF.
1024	!!----------------------------------------------------------------------
1025	!! * Arguments
1026	INTEGER, INTENT(IN) :: kt ! ocean time-step
1027	!!----------------------------------------------------------------------
1028	! ! the begining of the run [s]
1029
1030	IF ( ln_bias_rlx ) THEN
1031	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'tbias_rlx' , tbias_rlx_out )
1032	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'sbias_rlx' , sbias_rlx_out )
1033	ENDIF
1034
1035	IF ( ln_bias_asm ) THEN
1036	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'tbias_asm' , tbias_asm_out )
1037	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'sbias_asm' , sbias_asm_out )
1038	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'tbias_p' , tbias_p_out )
1039	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'sbias_p' , sbias_p_out )
1040	ENDIF
1041
1042	IF ( ln_incpc ) THEN
1043	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'tbias_asm_stscale' , tbias_asm_stscale_out )
1044	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'sbias_asm_stscale' , sbias_asm_stscale_out )
1045	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'tbias_i' , tbias_i_out )
1046	CALL iom_rstput( nn_bias_itwrt, nn_bias_itwrt, numbias_tot, 'sbias_i' , sbias_i_out )
1047	ENDIF
1048
1049	IF( kt == nitend ) THEN
1050	CALL iom_close( numbias_tot ) ! close the restart file (only at last time step)
1051	lrst_bias = .FALSE.
1052	ENDIF
1053	!
1054	END SUBROUTINE bias_wrt
1055
1056	END MODULE bias

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source: branches/UKMO/dev_r5518_GO6_package_FOAMv14_ASMFix/NEMOGCM/NEMO/OPA_SRC/ASM/bias.F90 @ 15749

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