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trasbc.F90 in trunk/NEMOGCM/NEMO/OPA_SRC/TRA – NEMO

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source: trunk/NEMOGCM/NEMO/OPA_SRC/TRA/trasbc.F90 @ 5296

Last change on this file since 5296 was 5120, checked in by acc, 9 years ago
#1473. Re-organisation and optimisation of ice shelf cavity option. This commit merges changes from the dev_r5094_UKMO_ISFCLEAN branch onto the trunk. Results will change, even with ln_isfcav=F, due to a return to original definitions of the vertical metrics. All changes have been reviewed and SETTE tested.
Property svn:keywords set to `Id`
File size: 16.5 KB

Rev	Line
[3]	1	MODULE trasbc
	2	!!==============================================================================
	3	!! * MODULE trasbc *
	4	!! Ocean active tracers: surface boundary condition
	5	!!==============================================================================
[2528]	6	!! History : OPA ! 1998-10 (G. Madec, G. Roullet, M. Imbard) Original code
	7	!! 8.2 ! 2001-02 (D. Ludicone) sea ice and free surface
	8	!! NEMO 1.0 ! 2002-06 (G. Madec) F90: Free form and module
	9	!! 3.3 ! 2010-04 (M. Leclair, G. Madec) Forcing averaged over 2 time steps
	10	!! - ! 2010-09 (C. Ethe, G. Madec) Merge TRA-TRC
[5120]	11	!! 3.6 ! 2014-11 (P. Mathiot) isf melting forcing
[3]	12	!!----------------------------------------------------------------------
[503]	13
	14	!!----------------------------------------------------------------------
[3]	15	!! tra_sbc : update the tracer trend at ocean surface
	16	!!----------------------------------------------------------------------
	17	USE oce ! ocean dynamics and active tracers
[888]	18	USE sbc_oce ! surface boundary condition: ocean
[3]	19	USE dom_oce ! ocean space domain variables
	20	USE phycst ! physical constant
[4990]	21	USE sbcmod ! ln_rnf
	22	USE sbcrnf ! River runoff
[216]	23	USE traqsr ! solar radiation penetration
[4990]	24	USE trd_oce ! trends: ocean variables
	25	USE trdtra ! trends manager: tracers
	26	!
[3]	27	USE in_out_manager ! I/O manager
[258]	28	USE prtctl ! Print control
[2528]	29	USE sbcrnf ! River runoff
[4990]	30	USE sbcisf ! Ice shelf
[2528]	31	USE sbcmod ! ln_rnf
	32	USE iom
	33	USE lbclnk ! ocean lateral boundary conditions (or mpp link)
[3294]	34	USE wrk_nemo ! Memory Allocation
	35	USE timing ! Timing
[4990]	36	USE eosbn2
[3]	37
	38	IMPLICIT NONE
	39	PRIVATE
	40
[503]	41	PUBLIC tra_sbc ! routine called by step.F90
[3]	42
	43	!! * Substitutions
	44	# include "domzgr_substitute.h90"
	45	# include "vectopt_loop_substitute.h90"
	46	!!----------------------------------------------------------------------
[4990]	47	!! NEMO/OPA 3.7 , NEMO Consortium (2014)
[888]	48	!! $Id$
[2715]	49	!! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt)
[3]	50	!!----------------------------------------------------------------------
	51	CONTAINS
	52
	53	SUBROUTINE tra_sbc ( kt )
	54	!!----------------------------------------------------------------------
	55	!! * ROUTINE tra_sbc *
	56	!!
	57	!! ** Purpose : Compute the tracer surface boundary condition trend of
	58	!! (flux through the interface, concentration/dilution effect)
	59	!! and add it to the general trend of tracer equations.
	60	!!
	61	!! ** Method :
[664]	62	!! Following Roullet and Madec (2000), the air-sea flux can be divided
	63	!! into three effects: (1) Fext, external forcing;
	64	!! (2) Fwi, concentration/dilution effect due to water exchanged
	65	!! at the surface by evaporation, precipitations and runoff (E-P-R);
	66	!! (3) Fwe, tracer carried with the water that is exchanged.
[3625]	67	!! - salinity : salt flux only due to freezing/melting
	68	!! sa = sa + sfx / rau0 / e3t for k=1
[664]	69	!!
	70	!! Fext, flux through the air-sea interface for temperature and salt:
[3]	71	!! - temperature : heat flux q (w/m2). If penetrative solar
	72	!! radiation q is only the non solar part of the heat flux, the
	73	!! solar part is added in traqsr.F routine.
	74	!! ta = ta + q /(rau0 rcp e3t) for k=1
	75	!! - salinity : no salt flux
[664]	76	!!
	77	!! The formulation for Fwb and Fwi vary according to the free
	78	!! surface formulation (linear or variable volume).
	79	!! * Linear free surface
	80	!! The surface freshwater flux modifies the ocean volume
[3]	81	!! and thus the concentration of a tracer and the temperature.
	82	!! First order of the effect of surface freshwater exchange
	83	!! for salinity, it can be neglected on temperature (especially
[664]	84	!! as the temperature of precipitations and runoffs is usually
	85	!! unknown).
[3]	86	!! - temperature : we assume that the temperature of both
	87	!! precipitations and runoffs is equal to the SST, thus there
	88	!! is no additional flux since in this case, the concentration
	89	!! dilution effect is balanced by the net heat flux associated
[664]	90	!! to the freshwater exchange (Fwe+Fwi=0):
	91	!! (Tp P - Te E) + SST (P-E) = 0 when Tp=Te=SST
[3]	92	!! - salinity : evaporation, precipitation and runoff
[3625]	93	!! water has a zero salinity but there is a salt flux due to
	94	!! freezing/melting, thus:
	95	!! sa = sa + emp * sn / rau0 / e3t for k=1
	96	!! + sfx / rau0 / e3t
[3]	97	!! where emp, the surface freshwater budget (evaporation minus
	98	!! precipitation minus runoff) given in kg/m2/s is divided
[4990]	99	!! by rau0 (density of sea water) to obtain m/s.
[664]	100	!! Note: even though Fwe does not appear explicitly for
	101	!! temperature in this routine, the heat carried by the water
	102	!! exchanged through the surface is part of the total heat flux
	103	!! forcing and must be taken into account in the global heat
	104	!! balance).
	105	!! * nonlinear free surface (variable volume, lk_vvl)
	106	!! contrary to the linear free surface case, Fwi is properly
	107	!! taken into account by using the true layer thicknesses to
	108	!! calculate tracer content and advection. There is no need to
	109	!! deal with it in this routine.
	110	!! - temperature: Fwe=SST (P-E+R) is added to Fext.
	111	!! - salinity: Fwe = 0, there is no surface flux of salt.
[3]	112	!!
	113	!! ** Action : - Update the 1st level of (ta,sa) with the trend associated
	114	!! with the tracer surface boundary condition
[4990]	115	!! - send trends to trdtra module (l_trdtra=T)
[503]	116	!!----------------------------------------------------------------------
[2528]	117	INTEGER, INTENT(in) :: kt ! ocean time-step index
[3]	118	!!
[2528]	119	INTEGER :: ji, jj, jk, jn ! dummy loop indices
[4990]	120	INTEGER :: ikt, ikb
	121	INTEGER :: nk_isf
[3625]	122	REAL(wp) :: zfact, z1_e3t, zdep
[4990]	123	REAL(wp) :: zalpha, zhk
	124	REAL(wp) :: zt_frz, zpress
[3294]	125	REAL(wp), POINTER, DIMENSION(:,:,:) :: ztrdt, ztrds
[3]	126	!!----------------------------------------------------------------------
[3294]	127	!
	128	IF( nn_timing == 1 ) CALL timing_start('tra_sbc')
	129	!
[3]	130	IF( kt == nit000 ) THEN
	131	IF(lwp) WRITE(numout,*)
	132	IF(lwp) WRITE(numout,*) 'tra_sbc : TRAcer Surface Boundary Condition'
	133	IF(lwp) WRITE(numout,*) '~~~~~~~ '
	134	ENDIF
	135
[4990]	136	IF( l_trdtra ) THEN !* Save ta and sa trends
[3294]	137	CALL wrk_alloc( jpi, jpj, jpk, ztrdt, ztrds )
	138	ztrdt(:,:,:) = tsa(:,:,:,jp_tem)
	139	ztrds(:,:,:) = tsa(:,:,:,jp_sal)
[216]	140	ENDIF
	141
[2528]	142	!!gm IF( .NOT.ln_traqsr ) qsr(:,:) = 0.e0 ! no solar radiation penetration
	143	IF( .NOT.ln_traqsr ) THEN ! no solar radiation penetration
	144	qns(:,:) = qns(:,:) + qsr(:,:) ! total heat flux in qns
	145	qsr(:,:) = 0.e0 ! qsr set to zero
	146	ENDIF
[3]	147
[2528]	148	!----------------------------------------
[4990]	149	! EMP, SFX and QNS effects
[2528]	150	!----------------------------------------
	151	! Set before sbc tracer content fields
	152	! ************************************
	153	IF( kt == nit000 ) THEN ! Set the forcing field at nit000 - 1
	154	! ! -----------------------------------
	155	IF( ln_rstart .AND. & ! Restart: read in restart file
	156	& iom_varid( numror, 'sbc_hc_b', ldstop = .FALSE. ) > 0 ) THEN
	157	IF(lwp) WRITE(numout,*) ' nit000-1 surface tracer content forcing fields red in the restart file'
[4990]	158	zfact = 0.5_wp
[2528]	159	CALL iom_get( numror, jpdom_autoglo, 'sbc_hc_b', sbc_tsc_b(:,:,jp_tem) ) ! before heat content sbc trend
	160	CALL iom_get( numror, jpdom_autoglo, 'sbc_sc_b', sbc_tsc_b(:,:,jp_sal) ) ! before salt content sbc trend
	161	ELSE ! No restart or restart not found: Euler forward time stepping
[4990]	162	zfact = 1._wp
	163	sbc_tsc_b(:,:,:) = 0._wp
[2528]	164	ENDIF
	165	ELSE ! Swap of forcing fields
	166	! ! ----------------------
[4990]	167	zfact = 0.5_wp
[2528]	168	sbc_tsc_b(:,:,:) = sbc_tsc(:,:,:)
	169	ENDIF
	170	! Compute now sbc tracer content fields
	171	! *************************************
	172
	173	! Concentration dilution effect on (t,s) due to
	174	! evaporation, precipitation and qns, but not river runoff
	175
[3625]	176	IF( lk_vvl ) THEN ! Variable Volume case ==>> heat content of mass flux is in qns
[3294]	177	DO jj = 1, jpj
	178	DO ji = 1, jpi
[3625]	179	sbc_tsc(ji,jj,jp_tem) = r1_rau0_rcp * qns(ji,jj) ! non solar heat flux
	180	sbc_tsc(ji,jj,jp_sal) = r1_rau0 * sfx(ji,jj) ! salt flux due to freezing/melting
[2528]	181	END DO
[3]	182	END DO
[3625]	183	ELSE ! Constant Volume case ==>> Concentration dilution effect
[2528]	184	DO jj = 2, jpj
	185	DO ji = fs_2, fs_jpim1 ! vector opt.
	186	! temperature : heat flux
[3625]	187	sbc_tsc(ji,jj,jp_tem) = r1_rau0_rcp * qns(ji,jj) & ! non solar heat flux
	188	& + r1_rau0 * emp(ji,jj) * tsn(ji,jj,1,jp_tem) ! concent./dilut. effect
	189	! salinity : salt flux + concent./dilut. effect (both in sfx)
	190	sbc_tsc(ji,jj,jp_sal) = r1_rau0 * ( sfx(ji,jj) & ! salt flux (freezing/melting)
	191	& + emp(ji,jj) * tsn(ji,jj,1,jp_sal) ) ! concent./dilut. effect
[2528]	192	END DO
	193	END DO
[4990]	194	IF( iom_use('emp_x_sst') ) CALL iom_put( "emp_x_sst", emp (:,:) * tsn(:,:,1,jp_tem) ) ! c/d term on sst
	195	IF( iom_use('emp_x_sss') ) CALL iom_put( "emp_x_sss", emp (:,:) * tsn(:,:,1,jp_sal) ) ! c/d term on sss
[2528]	196	ENDIF
	197	! Concentration dilution effect on (t,s) due to evapouration, precipitation and qns, but not river runoff
	198	DO jn = 1, jpts
	199	DO jj = 2, jpj
	200	DO ji = fs_2, fs_jpim1 ! vector opt.
	201	z1_e3t = zfact / fse3t(ji,jj,1)
	202	tsa(ji,jj,1,jn) = tsa(ji,jj,1,jn) + ( sbc_tsc_b(ji,jj,jn) + sbc_tsc(ji,jj,jn) ) * z1_e3t
	203	END DO
	204	END DO
[3]	205	END DO
[2528]	206	! Write in the ocean restart file
	207	! *******************************
	208	IF( lrst_oce ) THEN
	209	IF(lwp) WRITE(numout,*)
	210	IF(lwp) WRITE(numout,*) 'sbc : ocean surface tracer content forcing fields written in ocean restart file ', &
	211	& 'at it= ', kt,' date= ', ndastp
	212	IF(lwp) WRITE(numout,*) '~~~~'
	213	CALL iom_rstput( kt, nitrst, numrow, 'sbc_hc_b', sbc_tsc(:,:,jp_tem) )
	214	CALL iom_rstput( kt, nitrst, numrow, 'sbc_sc_b', sbc_tsc(:,:,jp_sal) )
	215	ENDIF
	216	!
[4990]	217	!
[2528]	218	!----------------------------------------
[4990]	219	! Ice Shelf effects (ISF)
	220	! tbl treated as in Losh (2008) JGR
	221	!----------------------------------------
	222	!
	223	IF( nn_isf > 0 ) THEN
	224	zfact = 0.5e0
	225	DO jj = 2, jpj
	226	DO ji = fs_2, fs_jpim1
	227
	228	ikt = misfkt(ji,jj)
	229	ikb = misfkb(ji,jj)
	230
	231	! level fully include in the ice shelf boundary layer
	232	! if isfdiv, we have to remove heat flux due to inflow at 0oC (as in rnf when you add rnf at sst)
	233	! sign - because fwf sign of evapo (rnf sign of precip)
	234	DO jk = ikt, ikb - 1
	235	! compute tfreez for the temperature correction (we add water at freezing temperature)
	236	! zpress = gravrau0fsdept(ji,jj,jk)*1.e-04
	237	zt_frz = -1.9 !eos_fzp( tsn(ji,jj,jk,jp_sal), zpress )
	238	! compute trend
	239	tsa(ji,jj,jk,jp_tem) = tsa(ji,jj,jk,jp_tem) &
	240	& + zfact * (risf_tsc_b(ji,jj,jp_tem) + risf_tsc(ji,jj,jp_tem) &
	241	& - rdivisf * (fwfisf(ji,jj) + fwfisf_b(ji,jj)) * zt_frz * r1_rau0) &
	242	& * r1_hisf_tbl(ji,jj)
	243	tsa(ji,jj,jk,jp_sal) = tsa(ji,jj,jk,jp_sal) &
	244	& + zfact * (risf_tsc_b(ji,jj,jp_sal) + risf_tsc(ji,jj,jp_sal)) * r1_hisf_tbl(ji,jj)
	245	END DO
	246
	247	! level partially include in ice shelf boundary layer
	248	! compute tfreez for the temperature correction (we add water at freezing temperature)
	249	! zpress = gravrau0fsdept(ji,jj,ikb)*1.e-04
	250	zt_frz = -1.9 !eos_fzp( tsn(ji,jj,ikb,jp_sal), zpress )
	251	! compute trend
	252	tsa(ji,jj,ikb,jp_tem) = tsa(ji,jj,ikb,jp_tem) &
	253	& + zfact * (risf_tsc_b(ji,jj,jp_tem) + risf_tsc(ji,jj,jp_tem) &
	254	& - rdivisf * (fwfisf(ji,jj) + fwfisf_b(ji,jj)) * zt_frz * r1_rau0) &
	255	& * r1_hisf_tbl(ji,jj) * ralpha(ji,jj)
	256	tsa(ji,jj,ikb,jp_sal) = tsa(ji,jj,ikb,jp_sal) &
	257	& + zfact * (risf_tsc_b(ji,jj,jp_sal) + risf_tsc(ji,jj,jp_sal)) * r1_hisf_tbl(ji,jj) * ralpha(ji,jj)
	258	END DO
	259	END DO
	260	IF( lrst_oce ) THEN
	261	IF(lwp) WRITE(numout,*)
	262	IF(lwp) WRITE(numout,*) 'sbc : isf surface tracer content forcing fields written in ocean restart file ', &
	263	& 'at it= ', kt,' date= ', ndastp
	264	IF(lwp) WRITE(numout,*) '~~~~'
	265	CALL iom_rstput( kt, nitrst, numrow, 'fwf_isf_b', fwfisf(:,:) )
	266	CALL iom_rstput( kt, nitrst, numrow, 'isf_hc_b' , risf_tsc(:,:,jp_tem) )
	267	CALL iom_rstput( kt, nitrst, numrow, 'isf_sc_b' , risf_tsc(:,:,jp_sal) )
	268	ENDIF
	269	END IF
	270	!
	271	!----------------------------------------
[2528]	272	! River Runoff effects
	273	!----------------------------------------
	274	!
[3764]	275	IF( ln_rnf ) THEN ! input of heat and salt due to river runoff
	276	zfact = 0.5_wp
[2528]	277	DO jj = 2, jpj
	278	DO ji = fs_2, fs_jpim1
[3764]	279	IF( rnf(ji,jj) /= 0._wp ) THEN
	280	zdep = zfact / h_rnf(ji,jj)
[2528]	281	DO jk = 1, nk_rnf(ji,jj)
	282	tsa(ji,jj,jk,jp_tem) = tsa(ji,jj,jk,jp_tem) &
	283	& + ( rnf_tsc_b(ji,jj,jp_tem) + rnf_tsc(ji,jj,jp_tem) ) * zdep
	284	IF( ln_rnf_sal ) tsa(ji,jj,jk,jp_sal) = tsa(ji,jj,jk,jp_sal) &
	285	& + ( rnf_tsc_b(ji,jj,jp_sal) + rnf_tsc(ji,jj,jp_sal) ) * zdep
[2715]	286	END DO
[2528]	287	ENDIF
[2715]	288	END DO
	289	END DO
[3764]	290	ENDIF
	291
[4990]	292	IF( l_trdtra ) THEN ! send trends for further diagnostics
[2528]	293	ztrdt(:,:,:) = tsa(:,:,:,jp_tem) - ztrdt(:,:,:)
	294	ztrds(:,:,:) = tsa(:,:,:,jp_sal) - ztrds(:,:,:)
[4990]	295	CALL trd_tra( kt, 'TRA', jp_tem, jptra_nsr, ztrdt )
	296	CALL trd_tra( kt, 'TRA', jp_sal, jptra_nsr, ztrds )
[3294]	297	CALL wrk_dealloc( jpi, jpj, jpk, ztrdt, ztrds )
[216]	298	ENDIF
[503]	299	!
[2528]	300	IF(ln_ctl) CALL prt_ctl( tab3d_1=tsa(:,:,:,jp_tem), clinfo1=' sbc - Ta: ', mask1=tmask, &
	301	& tab3d_2=tsa(:,:,:,jp_sal), clinfo2= ' Sa: ', mask2=tmask, clinfo3='tra' )
[503]	302	!
[3294]	303	IF( nn_timing == 1 ) CALL timing_stop('tra_sbc')
	304	!
[3]	305	END SUBROUTINE tra_sbc
	306
	307	!!======================================================================
	308	END MODULE trasbc

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